Biomech Exam 2

Closed-chain hip adduction (pelvic obliquity) by gravity occurs in the absence of a sufficient contraction of the hip abductors.

The lateral hip ligament prevents further hip adduction. The arrow (to the right) represents the optional contraction of tensor fasciae latae to balance gravity's closed-chain adduction torque instead of relying on the ligament.

Where would each axis for the humero-radial joint be located?

The longitudinal axis for rotation would be in the CENTER of the radius (the blue line) ***Disregard the words- just look at the lines in the picture here

Reaching With Spasticity Patient at the VA with the fellow Michelle from last year - Mike reaching for balls with his right arm and reaching to the side to drop them in a container ***What I want you to recognize in this video is how his arc of motion is different and what kind of struggles he is having because of the fact that he cannot straighten his elbow

The patient does have a spastic UE b/c of a stroke - so his flexors are really tight and you will see how his movement is different along the entire line - His shoulder is tightened by the pec - His elbow is tightened by the biceps tone and the wrist and hand are also tight

The pectoralis minor is one of the major problem muscles that leads to anterior tilting

The pectoralis minor is one of the major problem muscles that leads to anterior tilting of the scapula which can then cause other problems - The pectoralis minor is one of those muscles - it's an antagonist to the serratus anterior The serratus anterior is arguably one of the most important muscles for upward rotation of the scapula which prevents impingement remember - So if your pectoralis minor is so tight that it's inhibiting the serratus anterior from doing its job, then we have all other sorts of issues - Like impingement syndrome - So pectoralis minor is a very common muscle to be tight b/c of postural faults

Vertebral Column

The vertebral columns, 33 vertebral bony segments - 7 cervical segments - 12 thoracic segments- align with the number of ribs we have - 5 lumbar segments - 5 sacral segments - 4 coccygeal segments ***The sacral and coccygeal vertebrae are usually fused in adults. (looks like one bone) Forming individual sacral and coccygeal bones

- If we increase the size of the box - The larger moment arm increases the torque on L5 to be 72 Nm (double from the smaller box)

There are nearly double the compression force on the spine when carrying the larger box

Michael Melnik's Principles • Principles of low back care: - Keep the curves/ Keep it close - Staggered stance - Build a bridge - Prepare and compensate

These 4 principles can really help you break down any activity and problem solve how to minimize lower back pain and take off some of the load

Michael Melnik's Principles • Principles of low back care: - 1. Keep the curves/ Keep it close - 2. Staggered stance - 3. Build a bridge - 4. Prepare and compensate 1. Keep the curves/ Keep it close

These 4 principles can really help you break down any activity and problem solve how to minimize lower back pain and take off some of the load 1) So you want to keep the natural curves of the spine and keep the load CLOSE to our center of gravity

Which of the following signals is afferent (part of an ascending tract conducting centrally) - Pain signals from touching hot stove- afferent - Light touch signals of feather brushing your shoulder- afferent - Motor signal for muscle contraction- efferent - Constant touch like feeling of tight gloves- afferent - Muscle fiber stretch signal- afferent - All except C - All except C and E - All are ascending

- All except C

Nerve Physiology: Excursion • Peripheral nerves adapt to the movement of joints Active movement results in greater excursion of nerves than???

Active movement results in greater excursion of nerves than passive movement • Changes in any joint movement can affect nerve excursion proximally or distally - • Support the continuum theory

Sternocleidomastoid (SCM) • Attachments on the sternum, proximal clavicle and the mastoid process of the skull • Contributes to neck and head WHAT??

Contributes to neck and head (as a unit) forward flexion and rotation • Can produce extension of the head (craniocervical joint) and compression of the cervical vertebrae

The anterior hip ligament (iliofemoral ligament) helps maintain upright posture when what is weak?

when hip flexors are weak or absent

***Free nerve endings are the first nerve to come back after an injury!!! AND also the last to??

- Makes sense from an evolutionary standpoint and functional standpoint - Pain signals come back first AND they are the LAST to be lost in a nerve injury And the first to come back

Efferent: Exiting the CNS

- Motor signals - But there's a sensory component we should explore further

Kinesthetic Awareness - Things that DO NOT help with your kinesthetic awareness Negative impact - Muscle fatigue - Vibration - Hand-over-hand assistance

- Muscle fatigue - Vibration - Hand-over-hand assistance - Muscle fatigue - increases your risk of injury b/c can't fire as normally does and intrafusal muscle fibers are not going to kick in and identify when you need to stop or how much is too much for your muscle - (ex. 500 lb cooler) - Hand over hand assistance- when providing external feedback that is a completely different phenomenon and unnatural thing than if you were reach and doing the same thing yourself - Allows person to rely on you as an external source of guidance- this won't help them function independently when you're not there- does not help with kinesthetic awareness at all

How forces activate sensory receptors On the left is where you can see the muscle Muscular tendinous junction

- Muscular tendinous junction=where the muscle belly comes into contact with the tendon - The Golgi tendon organ is an important part too

Introduction to Sensation Cells in our left hemisphere's orientation association area that define the boundaries of our body- where we begin and where we end relative to the space around us Cells in our right hemisphere's orientation association area that orients our body in space so in general...

- Our left hemisphere teaches us where our body begins and ends - Our right hemisphere helps us place where the body is and where we want it to go

Merkel Cells

- Pressure and light touch- helps with dexterity - Close to the skin - Slowly adapting Merkel cells - VERY IMPORTANT - close to the surface of the skin- so one of the first after the hair follicles to sense TOUCH - pressure and light touch are sensed by Merkel cells When someone has a nerve injury like diabetic neuropathy - the nerve signals are affected - this cell is actually commonly affected Merkel cells= particularly affected in diabetic neuropathy

Kinesthesia - the system for sensing the position and movement of individual body parts.

- Receives information from the muscle fibers, paired with the skin's receptors contribute to our brain's imaginary map (or perception) of the body - Our kinesthetic senses are dynamic- more of where our body begins and ends and our dynamic movements and where we are in space but more DURING movement!! - Continuous background information to the CNS

Brain Function Cerebrum

- Receives sensory info and processes it to produce body movement - Two strips of cells make up the homunculi (motor and sensory homunculus): motor and sensory along the superior portion of the cortex (from ear to ear) - Located along the superior portion of the motor cortex

The feedback loop is very similar to what we just covered - Afferent arriving in SC or CNS - Sensory info comes from sensory fiber and info from muscle spindles - And goes up to DRG and brain - Brain sends info to anterior horn - Then sends info to muscle fibers Don't often talk about this interaction This double arrow area----what is this???

- This double arrow area b/w muscle fiber and sensory fiber - So muscle fibers actually have sensory fibers built into them NOT just an efferent signal telling the muscle to move b/c what you need is also for that muscle to be communicating back to the sensory system so that you can

Cerebellum

- Two hemispheres connected by the corpus callosum - Receives sensory info from and controls the opposite side of the body - Coordinates voluntary movements like posture, balance, and speech ***- It takes in the sensory information and responds to it appropriately

Appendicular skeleton is comprised of?

- Upper / lower extremities - Clavicle - Scapula - Pelvis

Proprioception and Kinesthesia - First what's the difference - How do these things help us in daily function? Your readings talk about this

- Vibration is not good for your sensory nerve endings - Basically if you hold onto a sander all the time, vibratory input causes nerve endings to malfunction so skin and joint receptors are less sensitive and less available to detect where your body is in space - Why you see so many carpentry injuries b/c they have less kinesthetic sense- they are not able to sense as well where their body is in space during that activity and now are more likely to cut a nerve or cut their finger off

So intrafusal fibers are very important to proprioception- to understanding where your body is in space

- The strongest sensory signal for proprioception - Joint receptors are not as strong for proprioception b/c they only kick in at joint end ranges - Most of what we do in daily life are in that middle range which your joint receptors cannot detect

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes

A common image of someone who has shoulder tightness - b/c her humeral head can't shift in capsule appropriately, she is shifting her whole shoulder girdle and scapula forward when she is trying to reach behind her back

Clinical Pearl A dyskinesia is an abnormal movement pattern

A dyskinesia is an abnormal movement pattern - This can happen when part of the joint is stiff, when a muscle doesn't contract or lengthen properly, or when there is pain (to name a few reasons) - If the TMJ is not working properly, functional consequences can be large - b/c can affect your talking, eating, and chewing - Kinesiotape can be used to correct body dyskinesias by increasing awareness and improving neuromuscular control

Review and application Just another example of how the effort arm is of a certain length, and then if you cut the resistance arm or extend it?

if you cut the resistance arm to be RA1 there, it will be SHORT and therefore cause problems if you go 2/3 down the forearm, like RA2, generally it is going to be much more stable and actually prevent elbow motion

Are Joint receptors or intrafusal fibers the strongest sensory signal for proprioception?

intrafusal fibers are the strongest sensory signal for proprioception - Joint receptors are not as strong for proprioception b/c they only kick in at joint end ranges - Most of what we do in daily life are in that middle range which your joint receptors cannot detect

The proximal carpal row is called the intercalated segment- what does this mean?

it just means that it doesn't have strong attachments for muscle function - So there are no tendons that actually attach to the proximal carpal row - So therefore, it relies on its attachments to other structures around it through ligaments in order to shift and move with the wrist

When someone has a trauma or a major injury, the volar plate can become tighter or not slide as well when there is a lot of swelling

or when its immobilized for a long time, it can actually tighten and then not allow full extension

UE reach patterns • UE reach patterns depends on variety of scapular movements So here's a couple functional patterns: - Forward reach:

scapular (ST) protraction, shoulder flexion and elbow extension - Need to have protraction at the ST joint, shoulder motion

UE reach patterns • UE reach patterns depends on variety of scapular movements So here's a couple functional patterns: - Placing the hand high above the head

scapular (ST) upward rotation, GH external rotation, full shoulder flexion and elbow extension

- Muscle spindles: extrafusal fibers provide information about the muscle contraction force whereas intrafusal fibers are more about?

about the speed or rate of change and the length of muscle fibers - Muscle also has the Golgi Tendon Organ GTO in it which provides information during activities about the length and tension on that tendon - GTO acts together with sensory receptors and intrafusal fibers to maintain or change the contraction during activities

**Pruritis disorders-

disorders of itching Itching is also a sign of healing - you know that pain signals are one of the first to come back after a nerve injury, so assuming that nerve is healing- the pain signals are going to come back first, temperature, AND itching - Itching is a good thing! There is an itch/scratch cycle - itching is relieved by this temporary pain signal coming from this scratch - serotonin is released from your brain which can cause more itching

Which fibers provide information to the brain about the forces produced during muscle contraction? extrafusal fibers intrafusal fibers semicircular canal labyrinthe artery

extrafusal fibers

register information regarding motion of the head in the coronal plane (head tilting and lateral movements)

hair cells in the utricles

Which nerve fibers provide information from the muscle to the brain in response to active and passive stretching? extrafusal fibers intrafusal fibers Ruffini receptors Motor end plate

intrafusal fibers

provide information about movement in the sagittal plane (up and down, forward and back)

sacculae

Opening and closing of the jaw is a combination of

• Opening and closing of the jaw is a combination of both translation and rotation • TMJ= One of most frequently used joints in the body, used to: - - Talk, chew, yawn, swallow and sneeze

Head and torso - Protect delicate life supporting organs

• Skull (protects brain), spine (protects SC), ribcage (heart and lungs), and pelvis (reproductive and GI tract)

Locations of the five vestibular sense organs - The two maculae are the sensory end organs of the static labyrinth which signals head position - The three cristae, are the end organs of the kinetic or dynamic labyrinth, which signals head MOVEMENT

Each of these canals is set up in a different plane of movement - One in transverse, frontal, and sagittal planes

T/F--Recent evidence has shown that the most important part of proprioception (where is my body in space- or joint awareness) is generally due to intrafusal fibers providing info about the length of the muscle!!

TRUE!! - Remember, intrafusal muscle fibers are WITHIN the muscle belly - So it's very important, the brain receives information form the muscle belly about HOW STRETCHED that muscle is - This contributes to this big MAP that's happening in your brain- that whole right left hemisphere thing- where your body starts and ends and the position of your body in space

Temporomandibular Joint (TMJ)

TMJ is a synovial joint that connects the skull and the mandible and allows for translation and rotation • TMJ= One of most frequently used joints in the body, used to: - - Talk, chew, yawn, swallow and sneeze

Circumduction - Cone like motion that combines several movements

- It is not a true rotation because combines movements and involves more than one axis

When you are in supination, your interosseus membrane is in what kind of position?

When you are in supination, your interosseus membrane is in a maximum stretch position

Carpal Tunnel • The carpal tunnel becomes narrow during both wrist flexion and extension

When you both flex and extend your wrist you get narrowing of the carpal tunnel - That's why it is important to have one wear a splint at night to prevent them positions that would aggravate the carpal tunnel- a neutral wrjst splint- so no wrist flexion or extension

This is showing the roll and slide mechanics when you go into ulnar deviation versus radial deviation - So what we are seeing here is a dorsal view of the LEFT wrist - And when you see the roll and the slide - the scaphoid, lunate, and triquetrum which make up the proximal carpal row When you go into radial deviation what is happening?

When you go into radial deviation, the opposite occurs, so the capitate and the distal carpal row are pushing the proximal carpal row to slide down the incline of the radius towards the ulna When you do that, you can actually feel the triquetrum stick out on the ulnar side of your wrist

In-situ Buckle Force Transducers

"In-situ" means in the body Buckle force transducers are a device that they put on cadavers to assess how much tension or strain is placed on a nerve or a tendon at a certain point in the body So the buckle force transducers pull a tendon or nerve through those two spaces and then they assess what the reaction force is on the strain gauge when they apply a certain amount of tension

Kinesiology

"The study of movement from the perspective of musculoskeletal anatomy and neuromuscular physiology" (Green ch.1) - This second half of the semester is geared more towards a kinesiology approach

Reduced volume within the subacromial space is what causes impingement

***(Increased ST internal rotation, increased ST downward rotation, increased ST anterior tilt, and increased GH internal rotation)----all of these things REDUCE the subacromial space

Excursion- is really just movement of that nerve or tendon - In this case, we are talking about the nerve, distally or proximally

***Active movement results in greater excursion of nerves than passive movement - This is true of tendons and nerves

Remember back to head and torso lecture where Nikki said the muscles are going to move whichever segment is lighter/easier - So when a muscle contracts, it pulls one segment closer to the other

***BUT if the distal segment is the weaker one or is not stabilized by muscles around it, then that is going to be the one to move - If the proximal segment is not stable, and supported by other muscles around it, then its going to move that proximal segment - So that's why the first part of this slide is true! (- Without scapular stabilization, the GH muscles would cause scapular motion (opposite of the desired motion) instead of humeral motion.) - So you need your scapular muscles to stabilize before the GH muscles can work to effect the humerus

Subscapularis (runs along anterior side of the scapula) - so this attaches at the front of the humerus - the subscapularis is the muscle cut when a surgeon performs a total shoulder replacement - so it's very important and that's the reason that there are restrictions after a total shoulder replacement

***Remember, when the subscapularis, when it is removed or cut to do the total shoulder replacement, then they have to repair it - that repair of the muscle is what leads to many of the restrictions after surgery - so if that subscapularis is repaired, remember the subscapularis is responsible for internal rotation - so if we wanted to stretch the subscapularis, we would be going into external rotation since it performs internal rotation - when a muscle is repaired or sewn back together, we DON'T want to stretch it BUT we also don't want to resist it- allow strong contraction of that muscle b/c that is also going to cause a pull from origin to insertion so with post-surgical patients, therapists are often afraid to deal with b/c you don't really want to do anything wrong - but if you understand precautions and why they exist, you can do a really great job rehabbing that person

***The fact that the erector spinae muscles have a small moment arm, it's more about??

***The fact that the erector spinae muscles have a small moment arm, it's more about the control here and the endurance and not so much about mechanical efficiency of these muscles

What is the maximum stretch position of the interosseus membrane and what is the force that is going to cause farther stretch of the interosseus membrane?

***now we know that supination is the maximum stretch position and a compression force is going to cause farther stretch of the interosseus membrane

the spine looks a lot like those snake toys where you can pull on one side and it effects the rest of how the snake moves- similar to the spine

- ***If you change one part of the spine, it does have an impact on the rest of the body - Ex. A forward head or pelvic tilt, it's going to cause the rest of the spine to shift in response

REDUCED subacromial space- A lot of these motions listed are common when someone is self-propelling a wheelchair

- **So manual wheelchair users are at more of a risk of subacromial impingement

Degrees of freedom • "Degrees of freedom" refers to the number of axes around which a joint can rotate around • The glenohumeral (GH) joint of the shoulder has three degrees of freedom--what are they??

- - Flexion and extension (occurs in sagittal plane around a medial/lateral axis of rotation) - - Abduction and adduction (occurs in a frontal plane around an anterior-posterior axis of rotation) - - External and internal rotation (occurs in a transverse plane around a longitudinal axis of rotation)

Conclusion • Anatomy is extremely important

- - If you know the anatomy, you can better problem solve patient concerns and conditions - Kinesiology is based on anatomy and physiology, and it's a VERY important part of valuable, patient centered OT practice for any physical condition

Shoulder complex abduction • Scapulohumeral rhythm: --- Motion available to the GH joint alone does not account for the full range of elevation (abduction/flexion) available to the humerus

- - The remainder of the range is contributed by the scapulothoracic joint via its SC and AC linkages - - Under normal conditions, contributions of these joints result in a coordinated movement called the scapulohumeral rhythm (The Shoulder Complex, Norkin et al., 2nd Ed.) - The rhythm can be divided into three phases • Phase 1 the setting portion 0-30° • Phase 2 the critical phase 30° to 130° • Phase 3 the final phase 140° to 180°

"Shoulder complex" abduction • First the scapular muscles contract to stabilize the scapula

- - Without scapular stabilization, the GH muscles would cause scapular motion (opposite of the desired motion) instead of humeral motion. - - The scapula is smaller and lighter than the humerus so moves more easily • The scapular muscles allow the GH muscles to do their job efficiently

• The chain starts with proximal screening

- - focus on Stability BEFORE mobility - So we really want to focus on scapulohumeral rhythm to make sure things are working proximally before we focus too much on mobilizing the GH joint!

Scapular upward rotation - This is where the scapula moves as shown in the photo here during elevation of the arm Phases of arm elevation (includes scapular glenohumeral and sternoclavicular movement)- what are these phases?

- Early - Middle - Late

The Elbow and Forearm Elbow complex consists of which joints?

- Elbow joint - Humero-ulnar and humeroradial joints - Proximal radio-ulnar joint

We are going to get into the extrinsic muscles When are talking about the flexor muscles of the wrist: Flexor carpi radialis (FCR)

- - goes from medial epicondyle and inserts on the base of the second metacarpal - so it crosses the carpals, but its effect is by pulling on the metacarpal to cause a radial directed force on the wrist - It's going to pull that metacarpal towards the ulna at sort of that oblique angle where the muscle is pulling - But the effect is really the wrist flexion occurs with the FCR **Of course all of the muscles that cross the wrist can have an effect on wrist flexion because they cross anterior to the axis of rotation

You see you get 180 degrees of shoulder abduction- how much is this from the GH joint?

- 120 degrees of these is from the GH joint - 60 degrees from the ST joint

• Hip joint - Ball and socket joint, head of femur and acetabulum how many df?

- 3 degrees of freedom: flexion/extension, abduction/adduction, and internal/external rotation

Lateral edge of the acromion is where an impingement would occur

- A Subacromial impingement occurs under the acromion - It's the humerus coming up and pinching on the supraspinatus tendon in the subacromial area

Median Nerve Injury The median nerve can be compressed under the pronator teres

- A condition called pronator syndrome looks like carpal tunnel syndrome without nocturnal waking - So people generally don't get numbness and tingling that wakes them up at night when they have pronator syndrome A motor branch can be compressed under the fibrous arch of the flexor tendons - Anterior interossues nerve entrapment is displayed as loss of the long flexor to the index and thumb (FDP and FPL) i.e. can't flex the DIP. The median nerve also goes through a muscle that has two heads - Can be compressed under the pronator teres

Anatomy of the MCP joint. When we label the ACL and the PCL- those are the two different parts of the collateral ligament

- ACL = accessory collateral ligament - PCL= proper collateral ligament PCL (proper collateral ligament)= tightest in flexion

Pure wrist motions work in PAIRS!!! - So these synergistic movements Activation of FCR and FCU produce?

- Activation of FCR and ECU produced balanced flexion - They are pulling from both sides- versus if only one of them were pulling, you would get more of a deviation with it So if only the FCU is functioning and not the FCR, you are going to get very strict flexion of the wrist toward the ulnar side - Versus if the FCR and FCU are working together, you are more likely to get a neutral wrist flexion Same with FCU and ECU - cancel out flexion and extension to produce a balanced ulnar deviation

Latissimus dorsi - Actually attached to the front of the humerus

- Actually attached to the front of the humerus - b/c of that, it has a lot of actions- so as a scapular depressor it is less effective b/c it is pulling the scapula down indirectly by pulling on the humerus - when you pull the humerus down, there are ligamentous attachments that we discussed earlier, so the humeral head is actually pulling the scapula more downward - although the latissimus dorsi also pulls on the inferior angle as it crosses over the scapula on its way down to the lower back and pelvis

- Erector spinae muscles are not designed to take on a lot of force - They are more designed for ENDURANCE If you're bending with your back a lot and overusing these erector spinae muscles, its like stretching a rubber band repetitively so if you keep opening and closing a rubber band, over time it ends up wearing out

- All have seen a rubber band that's stretched out and cracking or just about to snap - This is pretty consistent with what can happen in your body - You get microtears all the time, but as you age, those tears become easier to have- so damage to muscles is more prevalent - It becomes even more important to have established good habits early on in life to use leg muscles meant for force generation ***The fact that the erector spinae muscles have a small moment arm, it's more about the control here and the endurance and not so much about mechanical efficiency of these muscles

Importance of the elbow - The connection between the shoulder and the hand

- Allows you to bring your hand to your mouth Some people overlook the elbow as a "simple" joint - b/c it's a hinge joint and just does flexion/extension but it's a lot more complicated - It's very important if you even lose a little elbow flexion or extension, you could lose your ability to feed yourself - It can affect your ability to perform hand gestures in normal communication and of course it can affect your ability to weight-bear- whether you are weight-bearing on the elbow and its sensitive or you are pushing yourself out of bed in the morning and you need that elbow to get straight so you can push yourself upright at the edge of the bed

- Now looking at Olivia who has her head slightly flexed at a 30 degree angle: - The erector spinae muscles have to work a lot harder to hold the head up against gravity - Erector spinae muscles are now contracting at a force of 7.5 kg

- And they also have to take on a load from the portion of the head's weight- so just know it's more than 7.5 kg that's being exerted at I guess, C6 would be the axis of rotation here - So we're having a lot more moment (torque at that joint) then the muscles are acting and contributing a lot more to this which can lead to fatigue and other issues

Axis of ankle joint • In neutral ankle position, the joint axis passes through - fibular malleolus - body of talus - through or just below the tibial malleolus

- At 14 degrees of inclination from the transverse plane - At 23 degrees of inclination from the frontal plane

- • The scapula moves in the following ways

- Elevate - Depress - Protract (also called scapular abduction) - Retract (also called scapular adduction) - Upward rotation (also called lateral rotation) - Downward rotation (also called medial rotation)

A lot of ligaments around the shoulder are named very specifically and easily- so you can figure out where the ligament is just based on the name

- Ex. Coracohumeral ligament - goes to the coracoid process of the scapula to the humerus - Also a coracoacromial ligament - goes from the coracoid process to the acromion process- this is one that is just inferior to the acromioclavicular ligament shown in this image

Articulations The "humero-ulnar" joint is a hinge joint

- Between trochlear notch of the ulna and trochlea of humerus - You can feel this when you cup your olecranon while you flex and extend - Forearm rotation (pronation/supination) has NO effect on this joint's function

The lower extremities - Carry the weight of the body on the LE during walking LE help maintain

- Carry the weight of the body on the LE during walking - LE help maintain balance and equilibrium during walking, standing, and sitting, and reaching Of course, the upper body does have an effect on the lower body if you lean one way reaching for something, it does require that the LE adjust to maintain balance

- Open packed is the loosest when the joint is in the most lax position or has the most accessory joint motion

- Close packed positions is where joints are the tightest and have the least accessory motion in the joint

Cervical Spine • The skull is attached to the neck via the atlas (atlanto-occipital joint)

- Connected via bilateral synovial joints - Primarily allow flexion and extension of the skull on the neck - Nodding motion • The atlas sits on top of the axis (atlantoaxial joint) - Rotates on the dens - Largest range of rotation occurs at this joint • Head and neck motion occurs throughout the cervical spine - Motion at the cervical spine allows the head to flex, extend, rotate and laterally flex - Combined motions also occur

Look at bottom picture and tell how the concave/convex rule applies for wrist extension - Open chain

- Convex on concave, opposite directions - Convex carpals on concave distal radius scaphoid/lunate roll posteriorly(toward dorsum) and glide anteriorly(toward palm).

Scapulohumeral abduction • Summary:

- Coordinated effort is necessary for full motion - The humerus moves more in the initial and final phases - In the middle phase the humerus and the scapula move in a 2:1 ratio - remember that the GH joint is moving 2 degrees and the scapula is moving 1 degree - Throughout the motion, the scapular muscles stabilize allowing the GH muscles to elevate the humerus vs. pull on the scapula

Primary scapular depressors - Lower trapezius - Latissimus dorsi - Pectoralis minor • These muscles can also pull the ribs,pelvis or humerus toward the scapula (closed chain for the scapula)

- Crutch walking and walker use

Reaching With Spasticity The patient does have a spastic UE b/c of a stroke - so his flexors are really tight and you will see how his movement is different along the entire line - His shoulder is tightened by the pec - His elbow is tightened by the biceps tone and the wrist and hand are also tight Treatment of Mike (Case Study)

- Did Kinesiotaping - He also has some nerve issues around his elbow so there is an extra piece of tape around his cubital tunnel that is where his ulnar nerve crosses the elbow Tried to facilitate elbow extension to try and make elbow extension a little easier for him

BONY end feel is HARD and unforgiving

- Ex. When you get into full elbow extension its basically bone on bone as the ulna hits the distal humerus - There's not going to be any accessory movement, no side to side with that

The Wrist: Articulations • The wrist joint is classified as a condyloid joint • The wrist joint has 2 degrees of freedom

- Flexion and extension in the sagittal plane - Abduction (radial deviation) and adduction (ulnar deviation) occur in the frontal plane **- So you are going to have more motion in ulnar deviation than radial deviation

We are going to get into the extrinsic muscles When are talking about the flexor muscles of the wrist: Flexor carpi ulnaris-

- Flexor carpi ulnaris- attaches to the fifth metacarpal base, causing a more ulnar directed flexion - ***This is the strongest wrist flexor - So when you go into wrist flexion - notice how you are going to go into more of an ulnar deviated position A couple of reasons for this but... - Just based on the fact that the surface of the distal radius doesn't allow much movement in that direction - So there's a lot more space to go towards the ulnar side because the ulna is generally a little shorter than the radius - With that disc, there's a softer block and therefore, there is less obstruction to moving in a flexion plane towards the ulnar side of the wrist

Clinical Pearl • In general, muscle balance is important. • We don't want one or only a few muscles to do all the work

- For example, an overused or contracted SCM could pull the medial clavicle up, leading to difficulty with the sterno-clavicular joint which would affect the acromio-clavicular joint and lead to shoulder dysfunction, spiraling into a complex problem to rehab

Circumduction is NOT anything like rotation that you would expect at a joint like your shoulder - A ball and socket joint that allows you to move your arm in a spiral fashion creating a cone-like motion

- For your wrist, you can do circumduction, but it is NOT a true rotation because it is really a combination of deviation and flexion/extension What happens when you combine some of these movements is you create kind of that cone movement - Which is called circumduction

- Degrees of freedom - You should be able to count them for every joint

- GH has 3 - Ulna on the humerus has 1 - Radius on the humerus has 2 - Radius on the ulna has 1

Muscles that produce GH motion • GH joint motion is very complex. • Besides requiring synergistic cooperation of the SC, AC and ST joints, the action of the muscles around the joint are dependent upon each other to determine how they will function

- GH joint motion is very complex BUT the shoulder girdle is really what is most complex

***Anterior interosseus nerve (AIN) is ONLY a motor nerve

- Gives you the ability to use your flexor digitorum profundus and your flexor pollicis longus - So someone with paralysis of this nerve would not be able to make an OK sign with a perfect circle of their index finger and thumb **Does not involve flexion of the DIP joint or the thumb in AIN syndrome

The hand on the right is a silver-backed gorilla - These are both CT renderings - On the left is a human hand - Can appreciate similarities and differences

- Gorilla's hands are used a lot more for weight-bearing- that's why the carpal bones in the right hand are a lot more compressed and osteoarthritic

Balance at the Hip - Gravity induces hip motion based on location of center of gravity hip flexion, extension occurs when gravity falls in which directions?

- Gravity flexes hip when upper body's center of gravity falls anterior to the frontal plane - Gravity extends hip when upper body's center of gravity falls posterior to side to side axis (frontal plane) - Hip muscles equalize gravity's action

Compensating for lack of supination involves Shoulder ADDUCTION and lack of pronation involves Shoulder ABDUCTION What could you do to decrease the compensatory strategy?

- Have a person put a ball or a towel under their elbow between their ribcage and elbow so that they cannot actually compensate - And then have them practice a functional activity while in that position - If they drop the item under their elbow, then you know they are unable to reduce that compensatory strategy

Anterior and posterior pelvic tilt • Following closed-chain movements reinforce lumbar curve and anterior pelvic tilt

- Hip flexors (iliopsoas) as they pull anteriorly on their origin, and back extensors (erector spinae) pull up on their origin (sacrum, iliac crest)

The bottom left shows how the scapula rides along the ribcage - This also helps to visualize for scaption, which we learned is a more functional movement pattern for raising your arm

- How the scapula fits really nicely around the ribcage and when it comes out into a more protracted state, it's going to be easier for the arm to elevate as well

Iliofemoral Ligament - Attaches your pelvis to the head of the femur - Can sometimes feel it, its like a band-like structure - The ligament is twisted and tense when standing which prevents the trunk from falling backwards

- If someone has more laxity in their joints, like the girl in the picture, they would theoretically compensate for that ligament laxity by maintaining really strong muscles around the hip like strong hip flexors would help keep this joint stable

Basically the scapular muscles have to kick in to stabilize that scapula or else your deltoid as it tries to pull your arm up into scaption

- If you look at how the deltoid functions, it would actually if it pulled in the opposite direction b/c the scapula is unstable or if its weaker, then the deltoid is actually going to pull the scapula into more of a downward rotation when we need it to go into upward rotation - In order to get the acromion out of the way for the humerus to move ***Scaption slide to this current slide are really important to understand!!!

The shoulder complex **** No single joint can allow elevation of the hand above the head - The term elevation is frequently used in place of either flexion or abduction. • You can use it generically but if you are describing an exercise or patient performance, you should be specific • Abduction and flexion are different motions involving different muscles.

- If you want to use the term elevation for the UE, it's fine, but just know that it's very vague - There's no single joint involved in bringing your hand over your head, it's a collaboration of all the joints we just discussed - So if one of those joints are not functioning properly, it can affect the whole shoulder girdle - If you are talking very generally about upper extremity movement, you can say arm elevation or UE elevation and it would mean really just like reaching up - But if you are talking about an exercise or describing what you are doing with a patient, you should try and be more specific especially during documentation

If you are trying to block both supination and pronation, you really need to block both the DRUJ and the PRUJ --what type of cast would you use for this?

- In the Muenster or Sugar Tong orthosis - prevent full forearm rotation, but in this one, they have the sides of the orthosis going around the epicondyles- allowing the olecranon to be FREE which will allow this person to maintain elbow flexion and extension while blocking forearm pronation and supination This can be relevant for some fractures and some wrist issues - This orthosis solves the problem because you are not blocking the elbow from an anterior or posterior aspect really much at all because there is just a strap around the dorsal side of the elbow - If it's soft enough, it also doesn't dig in so you don't get that issue with the leverage The other cast is a solution but she doesn't like how the wrist is hanging off the edge - The proximal edge of this orthosis above the elbow is LONGER so there is a lot more leverage to work with here- so it's a lot less likely to allow elbow motion at all, which would then prevent that rocking from happening

OSHA standards state the maximum lifting capacity for any person in the workplace is for dead weight- NOT lifting humans

- Is 50 POUNDS!!

Importance of the elbow

- It can affect your ability to perform hand gestures in normal communication and of course it can affect your ability to weight-bear- whether you are weight-bearing on the elbow and its sensitive or you are pushing yourself out of bed in the morning and you need that elbow to get straight so you can push yourself upright at the edge of the bed

Humero-Radial/Radio-Capitular Joint - has how many degrees of freedom?

- It has TWO degrees of freedom, flexion/extension and rotation at the forearm Where the radius articulates with the capitulum of the humerus Good practice is checking to see if the radial head feels the same on both the right and the left

It's also important to know that the standard for weight-bearing through the wrist, that 60% goes through the radius, 40% goes through the ulna - That is when the TFCC is FUNCTIONING and healthy

- It is a major stabilizer of the distal radioulnar joint. Allows forearm rotation by giving a strong but flexible connection between the distal radius and ulna Can see how the TFCC functions as a tight hammock or a trampoline that allows forces to be distributed more easily

Lateral Epicondylitis (LE) Tennis elbow, can also call this lateral tendinopathy - Can also call it an epicondylosis - in the literature saying it's a degenerative condition more than an inflammatory one - When you say epicondylitis - "itis" means inflammation - So want to reform how we talk about tendinopathy of the elbow Lateral aspect of elbow is sore, tender, and painful Due to overuse of common extensor tendon

- It is more common in people with jobs where they are overusing those tendons but also common in people with malnutrition of some kind or comorbidities that increase inflammatory response of the body - like diabetes A person may feel acute pain when fully extending the elbow - Especially when extending the wrist at the same time - Also with gripping b/c the most common muscle involved in lateral epicondylosis is the extensor carpi radialis brevis- it's the strongest wrist extensor and when we grip we use a tenodesis which means we put our wrist into a little extension while we squeeze- so that motion is going to use the tendon that extends the wrist and that's going to force some strain at the elbow - at the origin This is why a wrist brace can actually help lateral epicondylosis a lot!!

So with radial and ulnar deviation it is in the frontal plane

- It is moving around an axis that passes through the capitate - That is why you are going to put your goniometer axis on the capitate in order to measure radial and ulnar deviation

There's an axillary pouch- that's the inferior part of the capsule -also called the inferior glenohumeral ligament- this inferior glenohumeral ligament is really important when you are doing ABDUCTION

- It serves as a SLING to the humeral head - Can see this on the lower Right picture - As you raise your arm up, the upper portion of the capsule becomes slack, and the lower portion prevents the subluxation of the humeral head off the inferior portion of the joint

• Gastrocnemius is less of a mobility muscle and more of a dynamic stabilizer at the knee

- It works synergistically with quadriceps to increase stiffness of knee joint during gait

C1 is what holds your skull in place

- It's connected via bilateral synovial joints on each sides of those disks - Primarily flexion/extension of the neck - nodding "yes" - Sits on top of axis (C2) - Rotates on the dens - So when you turn your head side to side- the largest rotation occurs at the atlanto-axial joint

So when you move into radial deviation, your capitate, or the distal carpal row that is moving in line with the metacarpals

- It's going to cause a sort of compression and push the proximal carpal row more ulnarly So basically you get this shifting of the proximal carpal row towards the ulnar side of the wrist as it gets pressed down by the distal carpal row and causes that entire proximal carpal row to slide down the incline of the radius towards the ulna

- Kg is supposed to be a measurement of mass, and does NOT include the pull of gravity

- Kg is not a vector force b/c it is a measurement of mass not weight

- If a worker lifts a box, you are estimating compressive forces are going to be at his L5 and S1 segment of the spine (axis of motion) - Use Newtons and meters

- Kg is supposed to be a measurement of mass, and does NOT include the pull of gravity - Kg is not a vector force b/c it is a measurement of mass not weight

• Primary scapular elevators are

- Levator scapula - Upper trapezius So levator scapula clearly in the name is a scapular elevator And the upper trapezius is a scapular elevator Should be clear based on the origin and insertions, the angle of pull, the line of pull and the action of that muscle just by looking at it

So it's important to recognize when someone is doing a movement pattern that is creating this risk factor for impingement in the subacromial space

- Like ST and GH internal rotation- when we talk about GH internal rotation, an empty can position like when you push your thumb down, people will come in with shoulder pain - And when you ask people to raise their arm up, they will already have their palm to the floor or thumb to the floor as they are lifting their arm - they are rotating inward - Not sure if it's a bad habit or a tight pec muscle but they are already causing more of an impingement by being in this internally rotated position - So let them do this and then have them do the same motion but with their thumb pointed toward the ceiling in more external rotation - you are increasing the space below the acromion which allows better shoulder function without that impingement - It's not a fix it, but it's going to be a lot better and they should have a lot smoother motion and more ROM

Provocative Testing for the Ulnar Nerve Wartenberg's sign

- Loss of adduction of digits - Possible ulnar nerve compression at the elbow+ Most nerves have a sensory and motor component - The motor component means it powers different muscles - So for the ulnar nerve you can do a test seeing if they can pull their little finger in towards the ring finger- this may indicate ulnar nerve compression at the elbow - This may also indicate that there is an ulnar nerve issue at the wrist or farther down as well The idea here is that the intrinsic muscle is paralyzed that would normally pull the small finger in toward the ring finger - This is called Wartenberg's sign

Primary scapular depressors

- Lower trapezius - Latissimus dorsi - Pectoralis minor • As these muscles contract, or shorten, they pull the scapula toward the ribs, pelvis or humerus (open chain for the scapula)

Ulnar Nerve Stays on the ulnar side of the forearm to the wrist, then it's going to go through Guyon's canal - After Guyon's canal, the motor and sensory fibers SEPARATE, so you get cutaneous innervation to the small finger and half of the ring finger (sensation to the skin= cutaneous) - And muscular input so your muscles can contract to:

- Lumbricals 3-4 (only the ones that bend your MP joints and extend your IP joints to the 4th and 5th digits), hypothenar (OAF- opponens, abductor, and the flexor), palmar and dorsal interossei- ulnar to radial (b/c the ulnar nerve as it approaches the wrist, crosses the wrist and it actually plugs into muscles as it goes through those muscles- so it plugs into dorsal and palmar interossei from an ulnar standpoint since that's where it enters the hand, then it traverses over to the radial aspect of the hand and plugs into each muscle along the way) flexor pollicis brevis (deep head), adductor pollicis (one of the pinching muscles important especially during lateral pinch)

Introduction • Upper extremities are specialized for manipulation of materials and tool use • Manipulation of materials by the fingers and thumbs (tool use / hand use) depends on arm movement, positioning and stabilization • Various combinations of shoulder and elbow movements place the hand at multiple points in space • The shoulder complex contributes significantly to the freedom of the upper extremity

- Manipulation of the fingers and hand would not be possible without arm movement, positioning and stabilization - Shoulder complex contributes a lot to where the arm goes - Goes back to evolution when monkeys would swing in trees- the range they developed there with their arms in space while participating in purposeful activities like eating and hunting changed the neuromuscular system and the brain's process and helped us be where we are today

Retraction muscles

- Middle trapezius - primary - Rhomboids and lower trapezius as secondary muscles • This motion occurs primarily when the serratus anterior rests and the resting tone of these muscles provide a recoil action. • The retraction muscles themselves are not strong and cramp quickly with isometric contractions However, it is a really good thing to work on increasing muscle endurance of the retractors b/c it helps balance out the activity of the upper body - like when we're working in daily life, we tend to do things in front of us b/c that's where our eyes are - So we want to make sure we strengthen in the reverse just so we keep a good muscular balance

Clinical Pearl When a hip replacement is done through an anterior approach, the post-op restrictions include:

- No extension beyond neutral - No external rotation • Now that you know a little more about the ligaments at the front of the hip, it makes sense, right? • But, the risk of damaging nerves and important blood vessels is greater when accessing the joint from the front

Shoulder (GH) flexors and extensors • GH flexors are muscles that attach anterior to the axis of rotation. • GH extensors are muscles that attach posterior to the axis of rotation. • Think about the orientation of the supraspinatus muscle. Does it contribute to these motions?

- No!! - From origin to insertion, the supraspinatus muscle attaches very LATERALLY - So it is pretty much AT the axis of rotation - b/c of the way it attaches it actually has an effect on internal and external rotation of the humeral head - and of course it helps a little bit with abduction ONLY in the beginning range of motion - so from about 0-30 degrees is where it is most active for abduction of the shoulder

Medial Epicondylitis - Or Golfer's elbow - Overuse injury of

- Overuse injury of - Forearm flexor origin and pronator teres origin - Provocative tests - Palpate the medial epicondyle, positive if painful - PAIN is also reproduced with resisted wrist and finger flexion Contraction of the muscle bellies (concentric contraction) that are attached to the inflamed tendons cause pain at the origin - so basically you can test muscles individually by resisting wrist flexion alone in an ulnar fashion and a radial fashion The pain is further aggravated by resistance (isometric or eccentric contraction) - This is why it's important to understand how normal activities are going to further aggravate their condition and what NOT to do as well

- Scapulohumeral rhythm is the motion of the shoulder complex- scapula and humerus working together and all the joints we talked about The scapulohumeral rhythm is divided into 3 phases

- Phase 1- the setting portion - this is when your scapula needs to be stabilized and the supraspinatus can perform abduction in the initial range (b/w 0-30 degrees) - Phase 2- the critical phase - b/w 30 and 130 - Phase 3- the final phase- this is where it is primarily your deltoid contracting to bring your shoulder from 140 to 180 degrees

Introduction • Pinching the ulnar nerve at the elbow strains the lower trunk of the brachial plexus (it's origin). • Pinching a nerve root (level of the cervical spine) increases risk of nerve injury distally

- Picture of tug of war is exactly what your nerves DON'T want - So if you pinch the nerve in one area, like the girl in the pink is your neck - If the neck is pulling real hard b/c it's pinching on that nerve, then the lower part of the nerve is going to be affected by that - The lower part is going to be pulled along or it's not going to have as much movement - THE SAME IS TRUE IN THE OPPOSITE DIRECTION - So if you pinch a nerve root at the level of the cervical spine, it increases the risk of nerve injury distally - And if you pinch the ulnar nerve at your elbow which is also known as your funny bone, then strain will occur in the lower trunk of the brachial plexus which is its origin

Ankle Joint • Hinge joint - Lower ends of tibia and fibula with talus • Motion occurring at this joint is

- Plantar flexion vs. dorsiflexion - Prime movers: • Anteriorly: Tibialis anterior, • Posteriorly: Gastrocnemius & Soleus Sagittal plane and coronal axis

Gait • If you have a keen eye when observing gait alterations, you may be able to identify issues that contribute to:

- Poor seated posture, which of course affects the way one uses their arms or function in a wheelchair - Chronic pain which affects various aspects of life - Reduced muscle endurance which affects performance overall

Elbow Flexion Test - Fully flex the elbow- either with forearm in neutral or supination - and have person hold there for 30 seconds or so - Note the stretch of the ulnar nerve over the medial epicondyle Positive if WHAT?

- Positive if the small and ring fingers tingle - Indicates irritation of the ulnar nerve at the elbow

Stand Pivot Demo- video - Keep it close, keep the curves, build a bridge, staggered stance and prepare to compensate

- Prepare environment - Gait belt - put at patient's waist

Iliofemoral Ligament - Y-shaped

- Strongest ligament in the human body - In standing posture, the iliofemoral ligament is twisted and tense which prevents the trunk from falling backward

Shoulder complex abduction • The SETTING phase: 0-30° abduction (60° flexion) - Scapula seeks a position of stability in relation to the humerus (The Shoulder Complex, Norkin et al., 2nd Ed.)

- Primarily GH moves while the scapula stabilizes - This refers to "setting" the humeral head into the glenoid fossa - This is accompanied by depression of the humeral head (inferior translation)

Joint kinematics of the glenohumeral (GH) joint Flexion and extension, internal and external rotation (in 90 degrees of abduction)

- Primarily a spin between humeral head and glenoid fossa

Wrist Flexion/Extension • These movements involve three separate articulations:

- RADIO-CARPAL and ULNOCARPAL (proximal carpal row articulates with the radius and TFCC) - MID-CARPAL (proximal carpal row articulates with the distal carpal row)

Following closed-chain movements reinforce posterior pelvic tilt

- Rectus abdominis as it pulls up on its origin (pubis), and hamstrings as they pull posteriorly on their origin (iliac crest)

Glenohumeral movement (A) with and (B) without scapular stabilization. Notice that the amount of humeral movement remains the same in each case

- Remember, it's not just the GH joint that's working - So first the scapular muscles are supposed to contract to stabilize the scapula - The GH muscles otherwise would cause scapular motion- opposite of desired motion

Shoulder impingement • Sub-acromial impingement

- Repeated and damaging compression of the soft tissues that reside within the subacromial space - Reduced volume within the subacromial space • Orientation of the humerus and scapula and the resulting rotation angle of ST and GH joints • Increased ST internal rotation, increased ST downward rotation, increased ST anterior tilt, and increased GH internal rotation

Review of Kinematics Joint kinematics of the glenohumeral (GH) joint Joint kinematics:

- Roll - Spin - Slide - Compress - Distract/traction- pulling apart- traction is another word for distraction Joint movement occurs based on the joint shape, structure and forces acting on it

Joint kinematics of the glenohumeral (GH) joint Internal and external rotation

- Roll and slide along joint's transverse diameter

• The atlas sits on top of the axis (atlantoaxial joint)

- Rotates on the dens - Largest range of rotation occurs at this joint • Head and neck motion occurs throughout the cervical spine - Motion at the cervical spine allows the head to flex, extend, rotate and laterally flex - Combined motions also occur

The elbow and forearm Proximal radio-ulnar joint (PRUJ) - what actions occur here?

- Rotation of the forearm occurs at radio-ulnar joints - Supination and pronation

SC joint is important to look at but doesn't use very often clinically

- SC joint is important in terms of balancing the UE in making sure that if there is a problem with the shoulder, that it's not due to stiffness at this joint - It's sort of just part of your screening process to see if there is any pain or stiffness or asymmetry - So b/w one side and the other, you want to make sure that they are functioning similarly - Although a little bit of a difference wouldn't be super uncommon either b/c people tend to be more dominant in one extremity than the other

Shear forces are the same as???

- Shear forces are the same as FRICTIONAL forces - So its when the vertebra are sliding or translating on one another causing shearing force on the intervertebral disc

Wheelchair adjustment • High footrests- causes?

- Shift pressure distribution from posterior thighs to ischial tuberosities, which promotes posterior pelvic tilt as increased hip flexion pulls the ischial tuberosities forward through The hamstring link High and low footrests promote development of pressure sores • Correctly adjusted footrests place hips near 90 degrees and posterior thigh is contact with the seat and feet rest in neutral position

Closing The upper extremity is very complex It is important for occupational therapists to understand the biomechanics of upper extremity motion - We discussed joint structure - Muscle attachments and function - And external forces

- Shoulder is a ball and socket - Ulna on the humerus is a hinge joint - Radius on the humerus is a shallow ball and socket joint - The radius on the ulna is a pivot type joint for the PRUJ and the DRUJ

When Nancy stands at the sink, the L5 vertebra forms a 30-degree angle to the floor. Her elbows project 20 cm from the axis of motion at her L5 disk. B, When she bends over the sink, the L5 vertebra forms a 70-degree angle to the floor. Her elbows project 52 cm from the axis of motion at her L5 disk. - How do we recommend someone with lower back pain perform their ADLs at the sink?

- So If we actually use less extensor force by supporting one arm on the counter top, it's going to save her back a lot The other thing you can do is include a stool under this kind of sink and put one foot up on the stool which not only increases your base of support and throws your COG Bending at the knees allows Nancy to lower her face to the sink without bending her back.

Kinetic Chain - What happens to the shoulder during activities when an elbow flexion contracture occurs? You can see the boy on the left that because of the elbow flexion contracture, the arm does NOT hang the same way

- So even his resting position is changed - So because of that, what the person will try to do is keep their hands in the positions where they are symmetric because that is what they see and that is what other people see - So the boy might bring his hands into the same position where they are touching his thigh - If he does that, this actually causes the shoulder to rest in a slightly greater degree of extension - So this could start to cause some issues at the shoulder

You get 35-40 of external rotation requires for full arm elevation at the GH joint This is a good point because when we have a total shoulder replacement, the shoulder external rotation restriction is at somewhere between 0 and 30 degrees of external rotation after surgery

- That restriction lasts between 4 and 6 weeks- so its important to know that for full arm elevation you really need 35 to 40 degrees of external rotation - So this is something that doesn't come until the later phases of shoulder rehab after a total shoulder replacement

So think of your shoulder like a crane - --It's the pull in the opposite direction that allows the shoulder to be stable

- So even though, we're moving the arm into a forward and upward position - It is the lower trapezius muscle that needs to contract to hold the base down so that it doesn't tip up - Another analogy for this would be scapula as kind of like a boat - where if you are trying to launch a cannon out of a boat, it's not going to work b/c you need stable ground to have those reaction forces- right? Newton's laws - So if you shoot a cannon off a steel platform, its going to function right and nothing will happen to the base it is shooting from - But if you shoot it off a boat where it's unstable, then you get all this shifting and the boat will sink- so it doesn't work b/c of the ground reaction forces

Introduction • Every movement requires MULTIPLE systems to adapt: nerves, arteries and veins, skin, and, of course, skeletal.

- So every time you lift your arm or every time you move, you are expecting that your nerves, arteries, veins, and skin are gliding and functioning as it should and allowing that movement to occur - If there's a tightness or a scar tissue, then the movement allowed will change, whether that's conscious or subconscious- people will adjust to the amount of range they have allowed by their soft tissues and skeletal system

• NOTE: NERVES DON'T LIKE STRETCH OR STRAIN

- So nerves really don't like stress or strain, they like GLIDE!!!

Important nerve principles • Pulleys: You might ask why we don't want that to happen if its going to relieve tension on the nerve - But you don't want the nerve to pop out of its groove and then pop back in is because nerves don't like any kind of forces on it

- So shear forces, tension, vibration any kind of contusion or trauma to the nerve, they really don't tolerate any of that, they need to be able to move- like glide side to side and they really need blood flow and nutrients - That is what creates healthy nerves

Scapulohumeral rhythm • The combination of scapular and humeral movements results in what is commonly held to be a maximum range of elevation to 180 degrees • Overall, for every 2 degrees of movement at the GH joint there is 1 degree of movement at the ST joint (The Shoulder Complex, Norkin et al., 2nd Ed.)

- So that critical phase between 30 and 130 is where there needs to be a really nice rhythm b/w the humerus and the scapula - So every 2 degrees of movement at the GH joint, there is 1 degree of movement at the ST joint (It's a 2:1 ratio b/w that ROM) where the scapula needs to move at a consistent 1 degree of movement for every 2 degrees of GH shoulder movement

Gleno-humeral ligaments • The gleno-humeral capsule also consists of a network of ligaments that provide additional stability

- So the inferior glenohumeral ligament mentioned before is part of the GH capsule! Ligaments • Ligaments are generally named logically based on their location - - Glenohumeral • Refers to ligaments that connect the glenoid fossa and the humerus - - By the name you can figure out roughly where it is located • Ligaments stop motions that stretch them, - i.e. the inferior glenohumeral ligament stops the inferior glide of the humerus when it is fully abducted - So when a ligament is taut, the ligament is preventing further motion of that joint

Each of the nerves of the UE enters the forearm through a bifurcated muscle So the radial nerve enters the forearm through which muscle?

- So the radial nerve enters the forearm through the supinator muscle called the radial tunnel - The supinator can actually cause impingement to the nerve when it becomes hypertrophic like if you are overusing your supinator

• Second injury resulted in loss of all extensor movement. - If we had a second injury that resulted in loss of ALL extensor movement, then you would only have the flexors working- so every time you tried to grip, you are not going to have a balance between wrist extensors creating a tenodesis and the flexors of the fingers working together So then you would have wrist flexion with finger flexion which we all know what it means!!!

- So then you would have wrist flexion with finger flexion which we all know what it means from an insufficiency standpoint- you will have ACTIVE INSUFFICIENCY - that causes weakness and then you are going to get really poor habits because of this which can make retraining after the nerves recover its really hard to get the person to balance out the wrist again so that they can have a normal tenodesis motion with grip

Lower trapezius- Hoover considers to be the most effective scapular depression b/c it attaches to the spine of the scapula and its origin is on the spine

- So this downward angle of the fibers is directly pulling on the scapula to create a lowering movement

This is what we call neutral spine- can call it natural curves or pathologic curves - This is where the spine is expected to function at ITS BEST

- So this includes the spinal nerves where they project out b/w the vertebrae it's important to have a neutral spine so that we're not causing pressure on any of the nerves or causing joint stiffness or deformities b/c of abnormal postures that cause the discs to shift or vertebral bodies to shift Cervical spine has a lordotic curve- anterior convex - So in cervical you would say it is more concave on the dorsal side, but convex on the anterior side Thoracic is more convex on the posterior side, concave on the anterior side Lumbar is more concave on the posterior side, convex on anterior side Sacro-coccygeal is more convex on posterior side, concave on anterior side the spine looks a lot like those snake toys where you can pull on one side and it effects the rest of how the snake moves- similar to the spine - ***If you change one part of the spine, it does have an impact on the rest of the body - Ex. A forward head or pelvic tilt, it's going to cause the rest of the spine to shift in response

Clavicular protraction and retraction - Occurs around a vertical axis of motion - This is like when you pull your shoulder forward like you are going to round your shoulders into really bad posture - And also when you push your chest forward and your shoulder blades back - Could attempt to measure that via a birds eye view - Protraction is also going to occur a little bit with elevation and retraction with depression - So these are pretty hard to isolate all together Upward and downward rotation of clavicle occurs around the clavicle's longitudinal axis---details?

- So this is more of a rotation through the longitudinal axis of the clavicle and would happen more with accessory motions of the shoulder - 40 degrees of upward rotation occurs in shoulder flexion and abduction

So if we know the anterior scalene is really weak, what might we want to do? - Connects to mid portion of clavicle and goes to cervical vertebrae - Want to incorporate other muscles -

- So want to strengthen the deeper muscles around it so it doesn't have to act alone - But then also want to go to a gravity minimized or eliminated position for activities - (may want to go into a prone position with the head positioned over the edge of the mat and then have the person work on activating that muscle working on control by keeping cervical spine in neutral and then making small movements into cervical flexion, then maybe with a little bit of rotation or lateral flexion to get some of the surrounding muscles to kick in without a lot of resistance) - (could also go into a side-lying position, might be in a gravity reduced position here so you could do a lot of cervical flexion without gravity's impact- b/c it does go on the side a bit, the muscle will kick in during this position) - Especially if you're lying on your right side, the left anterior scalene is going to kick in more b/c it's going to try to pick the head up from falling down into the mat So see how side-lying and lying prone can decrease the resistance from the weight of the head on a muscle like the anterior scalene

movements of the scapula include - (A) elevation and depression, - (B) retraction and protraction - (C) upward and downward rotation. ***there is also another movement not listed - that is TILT

- So we can also describe the scapula from the anterior tilt standpoint or posterior tilt - So that is, if you imagine, you hold your hand up in the air and that you are going to vow something like in front of a court - Imagine that the top of your fingertips is the superior border of the scapula and the base of your hand is the inferior border of the scapula - Now if you bring the base of your hand toward you and then you push the fingers away, that tilting action is ANTERIOR tilt - ANTERIOR tilt - is when the inferior border of the scapula lifts away from the ribcage or thorax - Posterior tilt- is when the inferior border of the scapula lifts toward the ribcage or thorax

Eccentric versus concentric Poll everywhere: Name a peri-scapular muscle that is eccentrically contracting when lowering the arm to the side

- So when I have my arm overhead, remember my upward rotators are activating I guess we could call the deltoid a peri-scapular muscle but not really what I meant So just include all of the muscles that raise your arm up - When you lower your arm back down, those are the same muscles that are eccentrically contracting - Serratus anterior, and upper and lower trapezius

***Based on what we just talked about, which muscles are primarily stabilizing the scapula in 140-180 degrees ROM?

- So when we're in about 90 - 110 degrees of ROM, you can see that the scapula is upwardly rotating (when the inferior angle moves away along the ribcage) and the superior angle is moving toward the spine and a little bit inferior - that is upward rotation We talked about how upward rotation occurs with the serratus anterior and the lower trapezius - Now we know the lower trapezius attaches to the spine of the scapula near the medial border - So this one makes the most sense

If the ligament is too stretched out- we call that Attenuated --In order to test the The Lateral collateral ligament (LCL) integrity So if you want to test this (attenuation), you want the person to go into a shoulder internal rotation with their elbow almost fully straight - want to have a slight bend in the elbow because it allows the olecranon to pop a little out of the really bony part that it sits in

- So you basically very slightly flex the elbow and you are going to apply a stress or a force from MEDIAL TO LATERAL - So you want to see if that LCL can handle that additional lateral stress - If it's a positive test indicating that there is an injury there, it will either pop or you will feel a little bit of a shifting happening OR the person may just be in pain Generally a POP or a shifting sensation is the most valid in terms of what you are looking for b/c pain isn't always something we can rely on

- Wrist is part of the body that doesn't really have a lot of proprioceptive input So because of that, the wrist doesn't have much muscle belly that's crossing it, it's all tendinous - So that's why the wrist really doesn't have a lot of proprioceptive feedback

- So you rely more on the sensory feedback from the skin stretching, the mechanoreceptors that way and rely on how it feels in your forearm and the fingertips - So you are relying more on the sensation coming through your fingertips, the force to determine if you need to flex your wrist or extend your wrist to get a better grip on something Various ligaments arrange the carpal bones into an arch - This arch is CONVEX on the dorsal side and concave on the palmar side

Important to note that there is a bit of a CARRYING ANGLE in the elbow

- Somewhere between 4 and 8 degree angle for the axis of rotation of the elbow - Right at that trochlea you can kind of see that when you are extending the elbow straight in the photo, there is a bit of a carrying angle - The line from the humerus to the ulna is at a bit of an angle it's not a perfect straight position - But as you bend your elbow, because of this carrying angle that exists, it's actually going to during flexion, it's actually going to get closer to the mouth- so the angle changes as you come into more flexion - From anatomic position and in elbow flexion, you have a carrying angle - which we call a valgus- the proper term - so you have a valgus angle at the elbow joint

Erector Spinae • Runs mostly parallel to the vertebral column

- Spinalis (connects spinous processes) - Longissimis (connects transverse processes) - Iliocostalis (connects ribs) • Positioned close to the axes of the vertebrae - Lateral and posterior to the intervertebral "joints" - Small moment arms for motion - Participate in neck and back extension and lateral flexion

When you consider which joint is involved in a fracture...

- The elbow is one of the most CONGRUENT joints in the body meaning that all of the bones are very close together - b/c of that there's really no space in the joint for fluid or swelling to exist- so when swelling becomes a problem in the joint- the joint stiffness is a lot more likely to occur and cause long-term problems in rehab - so swelling around joint is going to be a problem and the hardware itself can limit the joint's ability to move as it did before the fracture

Wrist injuries that include the ulna nearly always involve casting or splinting of both the wrist and elbow. Radial wrist fractures alone rarely include casting the elbow - ex. Colles' Fracture knowing why you are doing something is really important to the profession!! And to your patients to show why these restrictions exist when you have a distal radius fracture, you don't always immobilize the elbow - it is also true that when a radial head fracture or dislocation occurs, there is a very brief immobilization period- b/c we don't want to block the elbow from moving!! Why is that??

- The elbow is so congruent and the bones are so close together that we don't want to have swelling occur and inflammation and then immobilization because when the swelling is there, it makes the joint really easy to stiffen up - For this reason, its really hard to get full elbow motion back

MCP Joints of the hand Flexion and extension of the MCP on the left And abduction on the right - Specifically showing the first dorsal interosseus which is connected to the index finger - The first phalanx is going to roll and slide in WHAT direction?

- The first phalanx is going to roll and slide in the SAME direction - This follows the concave convex rule - the CONCAVE surface of the phalanx sliding and rolling on the convex surface of the metacarpal head - You can see how that muscle is pulling the distal segment in that direction

Right at that trochlea you can kind of see that when you are extending the elbow straight in the photo, there is a bit of a carrying angle

- The line from the humerus to the ulna is at a bit of an angle it's not a perfect straight position - But as you bend your elbow, because of this carrying angle that exists, it's actually going to during flexion, it's actually going to get closer to the mouth- so the angle changes as you come into more flexion - From anatomic position and in elbow flexion, you have a carrying angle - which we call a valgus- the proper term - so you have a valgus angle at the elbow joint

Articulation of the radius and ulna The distal radius crosses over the ulna as you go into what motion? What is the proximal aspect of the radius doing?

- The radius crosses over the ulna as you go into PRONATION - So the distal aspect of the radius is actually crossing the ulna The proximal aspect of the radius is really just SPINNING In its place

focus on the following points

- The shoulder complex moves most efficiently when the SC, AC, Scapulothoracic and GH joints are all mobile, and have functioning muscles that work synergistically - If any one joint malfunctions, the shoulder complex must utilize different mechanisms to elevate the arm - The shoulder complex uses whatever muscles are working well and this leads to a dyskinesia- a poor movement pattern - Prolonged dysfunction can result in structures shortening (contractures) or lengthening too much (over stretched or weak, nonfunctioning muscles) - This kind of spirals that problem into a bigger issue

Looking at the second photo when the person comes into elbow flexion - You get a roll and a slide in the joint - The flexors and the anterior capsule are now loose at the front of the joint

- The ulnar nerve is now tight around the medial epicondyle - The posterior medial collateral ligament (MCL) is tight, the posterior capsule is tight and the extensors, which would be the triceps primarily is tight there

The distal radio-ulnar joint DRUJ- pivot joint

- The ulnar notch of the distal radius spins around the head of the ulna - Also contributes greatly to forearm rotation The ulna is essentially a stationary post extending via a hinge from the humerus The radius is securely attached via the interosseus membrane, while PRUJ and DRUJ are moderately loose (like the GH)

if you wanted to measure strictly glenohumeral (GH) joint movement, you would line your goniometer stable arm in line with the line that is extending with the glenoid - right at the GH joint you see this dotted line that extends out

- Then you see this arc of motion that the Glenohumeral (GH) joint is capable of there - So that's 120 degrees, so you would put your axis of rotation at the glenohumeral joint, you would have your stable arm in line with that dotted line, and then your mobile arm would be parallel along the line of the humerus When you are measuring the scapula and measuring the glenohumeral (GH) joint, there can be some nuances on where you put your goniometer - so that's a good thing to understand

How does the concave-convex rule work for the radius and ulna

- There is a concave surface of the radius and ulna - Convex surfaces of the proximal carpal row in orange

- So the lateral ulnar collateral ligament is on the OPPOSITE side of the ulnar collateral ligament (UCL) on the lateral side LUCL or LCL is going to support the elbow during flexion

- There's also more tension on the LCL when shoulder is in passive internal rotation In order to test the ligament's integrity - To find out if it either torn or injured in another way - If the ligament is too stretched out- we call that Attenuated

Abductors of the wrist (Radial deviation) --what are these two muscles?

- These are the main wrist abductors or radial deviators Abduction of the wrist is assisted by thumb muscles with tendons that cross the lateral aspect of the wrist including the abductor pollicis longus, extensor pollicis longus, and extensor pollicis brevis - All assist in radial deviation of the wrist since they all cross on that same angle

Normal carrying angle 5-15-degree valgus- angles greater than this stress which structures?

- When the carrying angle is more than that, there can be a strain on the medial collateral ligament on the medial side of the elbow - It can also cause problems for your ulnar nerve - Your ulnar nerve is really designed to tolerate the 5 to 15 degrees of valgus angle but if its any more than that, it does put additional stress on the nerve as it crosses that elbow

A consequence of nerve sliding relative to surrounding nonneural tissue is that shear forces may be imposed upon the nerve

- These shear forces or friction forces are higher with faster motions and when the wrist is positioned in flexion or extension compared with a neutral position This makes sense because the nerves do travel right next to tendons and so tendons next to nerves can also cause shearing forces to those nerves - That friction against the nerves really doesn't make it happy at all - When the wrist is positioned in flexion or extension, you are just adding forces to that nerve because of the narrowing carpal tunnel

3 muscles that are considered scapular depressors (lower trapezius, latissimus dorsi, pectoralis minor

- They are all positioned in a way that from insertion to origin, they are pulling the shoulder blade into a lowered position or into a scapular depression So as they contract, they create this scapular downward movement

Erector Spinae Muscles of the back that run along the spine are very thin and small - So go back to muscle density and remember number of fibers relate to the overall muscle force-generating capacity ***- Erector spinae muscles are not designed to take on a lot of force - they are more designed for???

- They are more designed for ENDURANCE - Designed to take on small movements of the spine in that natural curve where they function best and they don't have to work very hard or produce a lot of energy through contraction So if you compare erector spinae to muscles of the thigh, pretty clear why we say lift with the legs and not the back - So posture education is really important to patients - Explaining why these rules exist help them follow them

Trendelenburg's Sign. The pelvis tilts toward the normal hip when weight is borne on the affected side. [corrected] Trendelenburg sign/ Gluteus medius test • Elevation of the pelvis on the unsupported side means that the pelvis on the unsupported side is at the same height as the supported side.

- This elevation indicates that the gluteus medius muscle on the supported side is functioning properly (negative Trendelenburg sign).

In this particular X-ray the person had such a bad fracture around their elbow that they needed surgery - So when that is the case, we want to consider a few things: - Where is the fracture? - Which joint is it involving? - Is it outside of the joint (extraarticular) or inside the joint (intraarticular)

- This fracture here is intraarticular it is going INTO the joint - so the fracture fragments were actually impeding on the joint - When that's the case- you want surgery to put the fragments back in place so you can get good healing around the joint- otherwise the normal arthrokinematics of the joint would be off - Surgery doesn't things back together perfectly either - So keep in mind that arthrokinematics are going to be affected and changed from the surgery - although hopefully as close to normal as possible When you consider which joint is involved in a fracture... - The elbow is one of the most CONGRUENT joints in the body meaning that all of the bones are very close together - b/c of that there's really no space in the joint for fluid or swelling to exist- so when swelling becomes a problem in the joint- the joint stiffness is a lot more likely to occur and cause long-term problems in rehab - so swelling around joint is going to be a problem and the hardware itself can limit the joint's ability to move as it did before the fracture

The extensor hood is a very complex biomechanical complex

- This is a good picture to see the intrinsic muscles - The reason the lumbricals and other intrinsics can flex the MCP joint and also extend the IP joint at the same time is because they come from the volar axis so they stay volar or anterior to the MCP joint axis range of motion - And then they attach to this thing- the complex in the picture I am pointing to - they attach there, which then allows them to pull on the extensor hood to perform PIP and DIP extension So that changes its EFFECT on the axis of motion - So it's actually VOLAR to the MCP axis of motion - And then it runs dorsal to the DIP and PIP axis of motion

Capsular end feel is FIRM and spongy

- This is when we perform joint mobilizations

Wrist Flexion/Extension • Frontal axis passes through the center of the capitate bone

- This is where you are going to measure the radial/ulnar deviation - And its also a good place to remember its effective in flexion and extension

That's really what the continuum theory is - says that even movement of just your index finger distally does lead to a change in the nerve's tension along its entire path

- This means that when I extend my index finger, I am actually affecting the median nerve, where it attaches or comes from IN the CERVICAL SPINE So it means that every part of that nerve path has an effect on the proximal and distal aspect of that nerve

***When you are moving into scaption or abduction in a prone position, it is the LOWER trapezius that is stabilizing the scapula so that you can use your shoulder

- This seems a little counter-intuitive, because you are moving your arm over your head or forward The scapula is like a crane, the base of a crane, and your arm is the extension part of the crane- the long part - In order for a train to reach out and up into the sky, it has to have a really stable base, otherwise what would happen? - If that base wasn't heavy and stable, the base would tip over b/c you're adding a lot of weight to the end of it and your moment arm is way out there - So it doesn't take much weight out there to make the base tip up - EXCEPT that the base in this case is a lot heavier - If we didn't have that, the base would tip over and the crane would not function as it does

What about ligaments? Throwing: Tension on UCL So the UCL is where we worry most about a tear or overstretching - Either one of those is going to cause an INSTABILITY

- This topic becomes very controversial Tommy John surgery - made him a better pitcher afterwards because it made the medial side of the elbow very stable - When you get the UCL repaired = tommy john surgery A lot of high school and middle school parents want to get their kids this surgery as a preventive way to make them a better pitcher

TFCC functions • TFCC's primary functions are:

- To cover the ulna head by extending the articular surface of the distal radius - So it sort of makes the ulna and radius more in line for the carpal bones • Reinforcing the ulnar side of the wrist - It functions as a cushion for the ulnar carpal bones. Helps with load transmission across the ulnocarpal joint and partially load absorbing • About 20% of the total compression force that crosses the wrist passes through the fibrocartilage disc component of the TFCC ***Numbers will vary, but the thing to remember about the TFCC is that it absorbs forces through the wrist and allows for a distribution of forces between the radius and ulna When the TFCC is damaged, then 95% of the load through the radius and ulna is brought onto ONLY the radius

Takeaways • The needs of each patient differ based on their unique physical status and limitations • It's important for occupational therapists to be able to analyze the components of a patient's physical status in order to:

- To determine how to best protect necessary structures - Help in making appropriate recommendations to improve their function!

Also important to recognize that it's difficult to measure with a goniometer for true GH joint range versus shoulder abduction range (180 degrees) To measure this with a goniometer, you want your axis of rotation, stable arm and mobile arm to be where? ?

- To measure this with a goniometer, you want your axis of rotation to be right at the GH joint, but you want the stable arm to be parallel to the spine and the mobile arm to be in line with the humerus

There are two structural components of the elbow that will affect its direction of motion

- Trochlea- spool looking structure on the humerus right in front of the elbow joint - it articulates with the ulna - Capitulum- spherical looking structure that is part of the humerus on the radial side- articulates more with the radius

The Hand: Introduction • The hand is composed of - 19 bones (27 including carpal bones), - 18 intrinsic muscles, and - 18 tendons of extrinsic muscles

- Truly the "hand" is considered only DISTAL to the carpus - So the carpal bones really should not count

Important principles • Pulleys: - Maintain nerve or tendon position against skeleton- keeps everything really close and protected - Generally improve efficiency during movement by limiting bowstringing - E.g. Osbourn's ligament at the elbow

- Ulnar nerve at the elbow looks a lot like it in the picture- the ulnar nerve travels behind the medial epicondyle and Osbourn's ligament acts as a pulley - So that allows the nerve to stay right up against the skeleton while you bend your elbow - If the Osbourn's ligament wasn't there and the medial epicondyle was a bit more flat, then that nerve would be able to pop out of its groove and move volarly just because of the tension on it, so it can then pop over and sit on a more volar aspect - This would be called an ulnar nerve subluxation if that happened, but there are mechanisms to stop that from happening

As you can see, lifting a box with a forward flexed spine or flexing at the hips is where you get the most intradiscal pressure

- Versus lifting with the knees bent, this goes down a little bit - With an erect posture with the box slightly closer to your center of gravity then we have a little bit less pressure on the discs too

There is a common misconception that the elbow is very simple - It is more complicated *****We need to address the proximal radioulnar joint too which is technically part of the forearm NOT the elbow

- We need to address the proximal radioulnar joint too which is technically part of the forearm NOT the elbow but it is part of the consideration since those joints are so close together that we do address it with the elbow

Clinical Pearl • If cervical muscles are weak, how should we position the patient to start strengthening (in general)?

- We would want to reduce the effects of gravity - Tip: use an anatomy app or look at the muscle in isolation to better understand it's action, which helps determine gravity eliminated positions and activity modification

Anterior and posterior pelvic tilt Anterior pelvic tilt (lumbar curve) results from

- Weak abdominal (pregnancy) or hamstring muscles - Tight hip flexors (spasticity, CP, or seated posture)

Posterior pelvic tilt results from

- Weak hip flexors or back extensors - Tight hamstrings or abdominals

Arthrokinematics Can see the anterior soft tissue restrictions that are contributing to limitations in elbow extension Ex. A patient had an elbow flexion contracture of around 100 degrees- so basically she is sitting with her elbow flexed more than 90 degrees and when you passively try to straighten her, you see that the skin on the anterior side of the elbow is restricting her from gaining full range of elbow extension

- When this is the case, if that is a noticeable restriction, it may be possible to have a surgical consult to reconstruct the skin and maybe include extra skin (a graft) that you would put on top of the elbow to take that restriction away and then be able to focus on other things that are contributing to the elbow contracture

If she is flexing the hips at 30 degrees, then there is a reaction force of 139.6 kg through the erector spinae - So this is a compression force remember

- When we look at bending farther over at that 70 degree angle of hip flexion - It's going to cause a huge of force on the erector spinae muscles, and it's going to cause shear force as well

Arthrokinematics Can see the anterior soft tissue restrictions that are contributing to limitations in elbow extension

- When you get to the end ranges of extension, your anterior capsule is tight, your biceps and other elbow flexors are tight and of course your skin on top of the elbow is tight - These are all things we need to consider when someone is restricted in their range of motion at the elbow - So it's not always that the joint is stiff or that the soft tissues are stiff - If someone has spasticity in the elbow flexors for a prolonged period of time like years-

This is showing the roll and slide mechanics when you go into ulnar deviation versus radial deviation - So what we are seeing here is a dorsal view of the LEFT wrist - And when you see the roll and the slide - the scaphoid, lunate, and triquetrum which make up the proximal carpal row When you go into ulnar deviation, what is happening?

- When you go into ulnar deviation, the distal carpal row is pushing those three bones of the proximal carpal row to go UP the incline of the radius towards the radial side of the wrist So you are going to be able to go into ulnar deviation and feel your scaphoid pop out in the snuff box area of your wrist - So right at the base of your thumb joint but at the radial side of the wrist, you can feel the scaphoid bone pop out when doing ulnar deviation

The scapular upward rotators are going to use three muscles that are activating when you do this motion- what are they?

- When you reach your arm up, you are going to be using upper and lower trapezius and serratus anterior **This motion is very important for you during reaching tasks especially over your head b/c this is what's going to allow the acromion out of the way of the humerus - The humerus as it abducts, you know that the humeral head has to slide inferiorly in the joint- part of the arthrokinematics there and concave convex rule - So as the humeral head slides inferiorly in the GH joint it does get out of the way a little bit - But in order to continue that motion up to go to full range, you need for the scapula to rotate so the humerus doesn't just knock right into the roof or acromion of the shoulder joint

You are constantly adjusting your wrist position based on the length tension relationship - You are using tenodesis constantly without even knowing it - So you are constantly making these adjustments to get the force that you want Another interesting component is proprioceptive input

- Wrist is part of the body that doesn't really have a lot of proprioceptive input - Remember proprioceptive input comes a lot from muscles themselves- from the muscle BELLY from the intrafusal muscle fibers - So if you think about that the joint receptors really aren't relative to joint proprioception UNLESS you are in maximum extension or flexion or end range positions

• The elastic limit of a peripheral nerve is 7% to 20% of its normal length (kind of like the yield point) BUT Symptoms tend to occur before that limit - So you don't need to go to 20 percent of the nerve's elastic limit in order to cause damage to the nerve

- You are still going to have some symptoms because nerves don't get proper blood flow or nutrients when they are in a stretched position - You start to get these microtears just like you would when you pull on a rope that starts to fray like in the picture

Humero-Radial/Radio-Capitular Joint The radius has a shallow socket that articulates on the capitulum of the humerus near the lateral aspect of the joint

- You can feel this just distal to your lateral epicondyle, pronate and supinate to palpate the radial head rotating - It has TWO degrees of freedom, flexion/extension and rotation at the forearm

scapular upward rotators

- You have the upper trapezius pulling on the spine of the scapula near the acromion - The lower trapezius pulling down at the superior medial border or the superior angle - Serratus anterior is actually underneath the scapula against the ribcage, and it is attached to the medial border on the underside of the scapula or the anterior side of the scapula ----It is going to pull that inferior border of the scapula

Remember: We use these models, like the Reconstruction Model and the biomechanical frame of reference to: -answer practice and design questions, -explain WHY we are doing what we are doing -create an appropriate, patient-specific treatment plan!

- You should always know WHY you are doing something in a treatment or evaluation - Need to put thought into what you are doing as an OT

Loss of Supination 6. What muscles should you try to strengthen?

- biceps (primary supinator muscle), and supinator muscle

Forearm Rotation Another slide with the full range of motion compared to the FUNCTIONAL range of motion of pronation and supination

- both of them tend to be closer to 90 degrees, but you have to keep in mind that the shoulder can compensate a lot for forearm rotation - when you go into a fully supinated position - palm up - if you want to get change from a cashier -if you have a tightness in supination, you would compensate by pulling your elbow a little bit in closer, across your body almost that could simulate supination- so it brings your palm closer to palm up position the other thing to notice is pronation - this source is saying that normal ROM of pronation is only 75 degrees - think about the position you are when you type on the computer - granted your elbows are not right at your sides when you are typing, they are usually in a bit of an abducted position - this allows you to get more of a palm down position

Torso Movements Muscle contractions in three major groups of muscles produce cervical, thoracic and lumbar movements The erector spinae and transversospinalis cause movements in which sections?

- cervical, thoracic and lumbar motion

Carpal Tunnel • It is formed by?

- concave shape of the combined carpal bones (when we say concave in this image, we are really just talking about how all of the carpal bones of the proximal row are giving that concave shape when you look at this angle- so its not talking about the arthrokinematics as much here since it's a COMBINED shape that its making here) - with a fibrous roof provided by the flexor retinaculum • The flexor retinaculum attaches - on the ulnar side to the hook of hamate and pisiform bone - on the radial side to scaphoid and trapezium Flexor retinaculum is also called Transverse carpal ligament, or Anterior annular ligament

Loss of Supination 8. How would you prevent this from happening?

- educate patient on ROM while in the cast (if possible)- this is why you need to understand what is going on in the X-ray and confirm with the doctor what motions are allowed and restricted - isometric contractions while in the cast- again if this is approved - perform functional tasks while in cast, if allowed by surgeon

Pectoralis minor - on the lower picture - attaches to the coracoid process which is on your scapula - this does do a little bit of depression

- however, b/c of its small attachment to the scapula and being that its attachment is so close to the top of the scapula, what it's actually better at is the anterior tilt - so when the pectoralis minor is tight, you're pulling on the top of the scapula which is then tipping the scapula forward

• Ligaments stop motions that stretch them,

- i.e. the inferior glenohumeral ligament stops the inferior glide of the humerus when it is fully abducted - So when a ligament is taut, the ligament is preventing further motion of that joint

Lateral Elbow & Dance Test - Outline bony structures on the elbow - Lateral epicondyle - can see the olecranon process posteriorly - radial head is distal to that then you have the extensor muscle group that goes around and attaches to the lateral epicondyle

- if we wanted to assess the joint line here for radial head, the "dance test" - you basically palpate at the radial head and olecranon process and on the other side then you have the person extend their elbow, then flex back at the side - then you kind of want to just feel what the radial head is doing in that motion and then you want to kind of feel what the radial head is doing with pronation and supination - just trying to feel if there are differences on the right versus the left side

Third metacarpal which is more concave on the proximal aspect and more convex on the distal axis it is directly connected to which carpal bone?

- it is directly connected to the capitate

The Interosseus Membrane --This is a pretty complicated structure

- it makes the radius and ulna into a more singular structure - prevents the two bones from separating - allows the radius to rotate around the ulna distally during OPEN Chain movement basically forces are transferred from the ulna to the radius because of this interconnection look at the lines and the direction of the fibers for the interosseus membrane shown here

So the three ligaments of the hip's anterior aspect have an OBLIQUE trajectory - b/c of this, they are LOOSE in flexion and tight in extension

- just like when we said in standing, your hips are more in an extended position and this is where the iliofemoral ligament is tight is the anterior side of the hip

Loss of Supination 7. How would you stretch the interosseus membrane?

- manually hold onto the ulna and the radius, attempt to massage the membrane, prolonged stretch with a splint ****- also remember the weight-bearing force will help a lot more!! - But this is not always indicated (ex. Weight-bearing might not be allowed for 3 months after surgery)

Remember when we look at the axis of rotation, are the GH adductors going to run along the lateral or the medial aspect of the axis of rotation?

- medial

• Hallux valgus

- mostly in women - when anterior part of arch flattens (e.g. high heels) - changes pull of extensor hallucis longus ms.

• The flexor retinaculum attaches on the ulnar and radial sides where? Flexor retinaculum is also called Transverse carpal ligament, or Anterior annular ligament

- on the ulnar side to the hook of hamate and pisiform bone - on the radial side to scaphoid and trapezium

Loss of Supination 4. What functional tasks will be challenged with a loss of supination?

- opening a door, receiving change, EATING, page turning, etc.

Treatment techniques • Neuromuscular re-education - Scapular rhythm re-training - Posture training • Kinesiotape • Visual input • Physical cues • Demonstration • Repetition with and without resistance • Incorporate function using open and closed chain activities b/c scapulohumeral rhythm is such a big deal - we want to make sure we are retraining using neuromuscular re-education concepts

- posture training can be done with Kinesiotape - visual input- would be demonstrating on a scapular model or showing a person on an anatomy app what we're trying to do and how the shoulder is expected to work - physical cues- that would be tapping to facilitate the lower trapezius when we're trying to have it activate during reaching motions - demonstration - on your own self- so showing and putting their hand around my scapula to know how the scapular motion is supposed to exist when reaching- so they can feel and understand what normal motion is like - repetition with and without resistance- also known as rhythmic stabilization- this would be like incorporating an element of surprise so that the person Is expected to respond to a cue without knowing exactly what to expect (ex. Putting fingertips on medial border and telling them to resist her forces whenever they feel them- then occasionally when they are doing a task she may pull on their shoulder blade and say I want you to pull back and respond- it incorporates an element of responsiveness and surprise so that it can hopefully carry over to other functional activities- repetition and functional activities is really important - Incorporate function using open and closed chain activities- vary depending on what your goals are for rehab

What it's saying at the bottom is that the functional range allows people to - use a keyboard, pour from a pitcher, raise from a chair, holding a newspaper, cutting with a knife, putting a fork to the mouth, putting a glass to the mouth, holding a telephone Sure these things are going to be okay if you have the 30 to 130 range BUT anything higher

- range BUT anything higher level than this or if they want to go to work, there is problems with that range because it starts to affect other things like the shoulder that you'll compensate with to make up for that change in range

***now we know that supination is the maximum stretch position and a compression force is going to cause farther stretch of the interosseus membrane

- remember this b/c if you have a person with a distal radius fracture or elbow fracture, anytime they are immobilized in a certain position that may cause the interosseus membrane to tighten, then we may want to stretch it out in order for them to get full function back - so doing weightbearing when it is allowed by the surgeon it's a great time to incorporate it because you will get stretch of interosseus membrane which will help achieve appropriate range of motion

***Remember, when the subscapularis, when it is removed or cut to do the total shoulder replacement, then they have to repair it - that repair of the muscle is what leads to many of the restrictions after surgery - so if that subscapularis is repaired, remember the subscapularis is responsible for internal rotation

- so if we wanted to stretch the subscapularis, we would be going into external rotation since it performs internal rotation - when a muscle is repaired or sewn back together, we DON'T want to stretch it BUT we also don't want to resist it- allow strong contraction of that muscle b/c that is also going to cause a pull from origin to insertion so with post-surgical patients, therapists are often afraid to deal with b/c you don't really want to do anything wrong - but if you understand precautions and why they exist, you can do a really great job rehabbing that person infraspinatus is inferior to the spine of the scapula

When you hold a load, so you have a distracting force on your forearm-this places a distal-directed force predominantly through the radius - this makes sense b/c when your elbow is in extension which puts the olecranon and the proximal ulna into the groove, it sorts of locks into the humerus, this bony articulation is what is stopping the ulna from taking on so much of the force any force that the ulna does take on, remember the interosseus membrane is PUSHING that force onto the radius

- so most of the force is coming through the radius when you are holding a load - but the distraction actually slackens the interosseus membrane - if you know that most of the forces are going through the radius then imagine the radius pulling distally downward - when you have diagonal fibers of a certain length, when you move the radius downward, it pulls the fibers into more of a horizontal position - when the fibers are already of a certain length and you move them into a straight horizontal position, it brings the left fibers down closer to their origin which slackens the interosseus membrane

Angle of retroversion= the angle the GH axis

- so the axis of rotation at the GH joint is 30 degrees posterior to the frontal plane which is why they call it RETROVERSION

Interosseus Membrane Tightness in the interosseus membrane causes stiffness in which motion?

- supination is the position of maximum stretch of the interosseus membrane Tightness in the interosseus membrane causes stiffness in supination

Balance after tendon transfer This tendon transfer commonly done at the VA for someone who does not have a good tenodesis - if they can't get a good wrist extension because Extensor carpi radialis brevis (ECRB) is not working, what they will do is take the brachioradialis and lift it up from the underlying tissue and bring it over to the dorsal side of the wrist so it becomes a wrist extensor and then they sew it to the ECRB tendon

- that way, every time you contract the brachioradialis, your wrist is going to extend - this will give you more control with your fingers to hold onto a pencil or other functional tasks for bringing the fingers together with the thumb

6 different motions of the scapula - However when you are looking at upward rotation of the clavicle, it looks very different than upward and downward rotation of the scapula

- the same things but are not really - So what you should remember though is remembering upward and downward rotation in regards to the scapula, it is very important to function

We are going to get into the extrinsic muscles When are talking about the flexor muscles of the wrist: Palmaris longus

- the wrist flexor that passes centrally but does NOT go through the carpal tunnel - You can check if someone has it by having them bring their fingers all together sort of like if you are holding a marble with all of your fingertips then you are going to have them flex their wrist - You can see the palmaris longus pop out because it doesn't cross under the flexor retinaculum **Flexion of wrist is assisted by muscles with tendons that cross the wrist joint including flexor digitorum superficialis and flexor digitorum profundus

***The metacarpals and the distal carpal row are basically attached (especially the index finger and the middle finger) that's the CMC joints

- they are basically bracketed - so there's not a lot of movement especially between the distal carpal row and the index and middle finger metacarpals So that means when you bend your hand and the metacarpals are flexing, its really the distal carpal row moving in one segment together

Interosseus Membrane - a compression force through the hand is transmitted primarily through the wrist at the radiocarpal joint and to the radius - this force does what to the interosseus membrane?

- this force stretches the interosseus membrane and transfers part of the compression force to the ulna A compression force in contrast is going to STRETCH the interosseus membrane - this is because a compression force, when you are weight-bearing on your hand, is going to put most of the compression force going through the radius as well - this time its primarily because the radius has a larger weight-bearing surface and its generally longer than the ulna - so when the radius and ulna are the appropriate length they are supposed to be, the radius takes on 60% of weightbearing load - because of this, you are pushing the fibers on the radius side farther apart - so it makes sense that this would stretch the interosseus membrane

Forearm Rotation When we are looking at rotation - in an anatomical position, your forearms bones are parallel- so the radius and ulna are straight next to each other - when you go into a pronated position when you rotate your forearm you get a rotational movement with the radius that looks kind of cone-shaped

- this is the movement that is allowed just based on forearm rotation - this is also assuming that it is open chain

A compression force in contrast is going to STRETCH the interosseus membrane - this is because a compression force, when you are weight-bearing on your hand, is going to put most of the compression force going through the radius as well

- this time its primarily because the radius has a larger weight-bearing surface and its generally longer than the ulna - so when the radius and ulna are the appropriate length they are supposed to be, the radius takes on 60% of weightbearing load - because of this, you are pushing the fibers on the radius side farther apart - so it makes sense that this would stretch the interosseus membrane ***now we know that supination is the maximum stretch position and a compression force is going to cause farther stretch of the interosseus membrane

PRUJ is shown in the red circle on the drawing - the radius and ulnar are articulating together - the radius is being held against the ulna by the annular ligament - you can feel this if you poke on the lateral side of the elbow there is the "dance test" that you can do

- what this involves is placing both of your hands on the lateral aspect of the patient's elbows and then their forearms are supported on your forearms and you pull their arms into more extension and then a little bit more back into flexion at their sides So basically with the dance test- you do flexion and extension and then pronation/supination - you are really feeling for the radial head and how it moves along the lateral side of the elbow- and you are comparing each side - So you are trying to see if there is a difference from one side to the other which could indicate a dislocation at some point or just an instability at the lateral side of the elbow at the radial head

Here is how these same muscles: The lower trapezius, latissimus dorsi, and pectoralis minor work in the OPPOSITE direction

- when they work in closed-chain movements, they basically lift the pelvis up using the humerus and the upper arm to push - which is considered closed chain for the scapula - so this is relevant for crutch walking and walker use and also pushing yourself out of a chair

Forearm Rotation When we are looking at rotation - in an anatomical position, your forearms bones are parallel- so the radius and ulna are straight next to each other

- when you go into a pronated position when you rotate your forearm you get a rotational movement with the radius that looks kind of cone-shaped - this is the movement that is allowed just based on forearm rotation ****this is also assuming that it is open chain

Compressive Forces • We start our calculations with all of the same anthropometric data and estimated distances as we used for moment calculations

- • Start by estimating the location of the axis - • Determine the forces and their moment arms - • Calculate the moments on the axis (M=fd) - • Estimate the erector spinae reaction force - • Then, sum the downward forces

Toilet transfers and the lower extremity - • Bending forward reduces the moment due to the body weight at the knee

- • Therefore, quadriceps have to generate less force when person leans forward before - standing up - • Raised toilet seat reduces moment of body weight at knee

Recommended Maximum Level for L5-6 Compression The National Institute for Occupational Safety and Health (NIOSH) has recommended a "safe maximum" level for compressive forces on the spine. - • 3400 N is considered the maximum compressive force for L5-S1 (or any disk) • This translates to

- • This translates to about 764 lbs (this includes the weight of the body, reaction force of the muscles, and the weight of whatever it is that you are carrying) OSHA standards state the maximum lifting capacity for any person in the workplace is for dead weight- NOT lifting humans - Is 50 POUNDS!!

The Interosseus Membrane This is a webbed membrane that tethers the radius to the ulna. It prevents the two bones from separating, yet allows the radius to do WHAT??

. It prevents the two bones from separating, yet allows the radius to rotate around the ulna distally--during OPEN Chain movement Forces acting on the hand are transferred to the humerus through the ulna Forces from the humerus are transferred to the radius through the ulna

Kinematic Principles Associated with Full Abduction of the Shoulder

1. (2:1 Scapulohumeral Rhythm) Active shoulder abduction of about 180 degrees occurs as a result of simultaneous 120 degrees of GH abduction and 60 degrees of ST upward rotation. 2. The 60 degrees of scapula upward rotation is the result of a simultaneous elevation at SC combined with upward rotation at AC joint. 3. The clavicle retract at SC joint during shoulder abduction 4. The scapula posteriorly tilts and externally rotates during full shoulder abduction. 5. The clavicle posteriorly rotates around its own axis during shoulder abduction 6. The GH joint externally rotates during shoulder abduction This is really just a review - Understand this 2:1 ratio and the phases of shoulder motion

Extensors of the Wrist

1. Extensor carpi radialis longus- attaches on the second metacarpal base (index finger) 2. Extensor carpi radialis brevis- STRONGEST WRIST EXTENSOR- right next to the ECRL attaching to the third metacarpal base 3. Extensor carpi ulnaris - over by the fifth metacarpal base **Extension of wrist is assisted by muscles with tendons that cross the wrist joint including extensor digitorum, extensor indices and extensor digiti minimi

When we talk about wrist adductors we are talking about ULNAR DEVIATION --what are these two muscles?

1. Extensor carpi ulnaris 2. Flexor carpi ulnaris - Attach toward the ulnar side of the wrist - going to have more of an effect on ulnar deviation - These two muscles work together to ulnar deviate or adduct the wrist - when they work together as a synergistic pair, they allow the wrist to move more neutral so basically both sides are contracting to make sure it is a balanced force

Articulations • Metacarpophalangeal (MCP) Ligaments 1. Volar plate 2. collateral ligament what motions do these 2 structures prevent?

1. Volar plate- prevent hyperextension 2. Collateral ligaments- tightest when the MCP joints are in full flexion - These ligaments are going to RESTRAIN motion so that the fingers don't move beyond a safe range Volar plate prevents hyperextension beyond a certain point - Some people have tighter volar plates than others, but the MCP joints in general, do have the capacity to hyperextend - When you do this, you may feel a bit of tension near the metacarpal heads on the volar side of the hand - that's in part, due to the volar plate tightening to prevent hyperextension beyond that point Collateral ligaments= very important - A FAN-SHAPED ligament - It has certain fibers tight throughout the range - But the most important part here is collateral ligament is tightest when the MCP joints are in full flexion

Balance after tendon transfer • Radial nerve damaged, ECU cannot function—(so we cross it off our table here) - resulting in two problems:

1. Weak wrist extension accompanied with unwanted radial deviation - due to ECRL/B - because now instead of having three primary wrist extensors functioning at once, now you only have the radial wrist extensors - so you are going to get wrist extension towards the radial side and its going to be very obvious b/c you don't have the balance of ECU creating that NEUTRAL wrist extension like you did before 2. When trying to do ulnar deviation, it would result in flexion - due to FCU - this is because you don't have the balance here either to maintain a neutral wrist when you are going into ulnar deviation, you don't have the neutral from a flexion/extension standpoint - so the FCU is now your primary ulnar deviator even though your extensor carpi ulnaris was a BETTER ulnar deviator BEFORE IT got damaged

Michael Melnik's Principles • Principles of low back care: - 1. Keep the curves/ Keep it close - 2. Staggered stance - 3. Build a bridge - 4. Prepare and compensate - 2. Staggered stance

2) Where you put one foot slightly in front of the other and then put a little bend in your knees, so you're almost like crouching down but in a very supported and stable stance- this will help when you're required to shift your body weight quickly b/c you can easily shift your weight on top of one leg or the other- so it really helps you be prepared for anything- this also brings your COG closer to the floor and over your base of support

Full wrist Flexion to Extension 1. Distal carpal row moves on the proximal carpal row

2. Scaphoid and distal row move on the lunate/triquetrum 3. the carpals move as a unit on the radius and triangular fibrocartilage complex to achieve full wrist extension

A posterior view of the lower trapezius and the latissimus dorsi depressing the scapulothoracic joint. These muscles are pulling down against the resistance provided by the spring mechanism.

3 muscles that are considered scapular depressors (lower trapezius, latissimus dorsi, pectoralis minor

Michael Melnik's Principles • Principles of low back care: - 1. Keep the curves/ Keep it close - 2. Staggered stance - 3. Build a bridge - 4. Prepare and compensate 3. Build a bridge

3) Means that like when Nancy puts her hand on the countertop when she's washing her face, so it takes the load off- so building a bridge means increasing contact points to the ground (ex. Midterm exam Q with walker # of contact points then throw a line around them) and however much SA is there is considered to be the base of support, so the larger the base of support, the more stable the person is going to be- so increased contact points increases overall stability

Michael Melnik's Principles • Principles of low back care: - 1. Keep the curves/ Keep it close - 2. Staggered stance - 3. Build a bridge - 4. Prepare and compensate 4. Prepare and compensate

4) This is very simple, if you cannot resolve the problem by using the first three rules, then you need to look at "how can we change the job?" "how can we change the environment?" "how can we change ourselves" - so what things are in our control that we can adjust about this to reduce the risk factors for injury - so for prepare, think about obstacles in our way of moving something- say before you bring a heavy box that you cannot see over into the house, maybe you trace your steps first of where you are going and is there anything in your way you can trip over? Another thing would be reducing the weight, taking multiple trips! Another option would be just strengthening ourselves and conditioning ourselves to be prepared for the job

Brief Synopsis: If you look at the scapulothoracic (ST) joint, you get...

60 degrees of upward rotation with full arm elevation

Tommy John surgery - made him a better pitcher afterwards because it made the medial side of the elbow very stable - When you get the UCL repaired = tommy john surgery

A lot of high school and middle school parents want to get their kids this surgery as a preventive way to make them a better pitcher - So it reduces their risk of course because they don't have to worry about having an UCL tear or injury, but it puts them above everyone else in a way - It gives them an unfair advantage And anytime there is a surgery there comes risk- which is why this is a controversial idea

- This is a way to understand extrinsic muscles that cross the wrist and their effect on motion - Shows each muscle's moment arm for producing wrist flexion, extension, deviation You see the ECRB being a really great wrist extensor, but not as good as a radial deviator as extensor carpi radialis longus

Another example is flexor carpi ulnaris- not as good of an ulnar deviator as extensor carpi ulnaris, but the FCU is a little bit better of a flexor than the FCR just based on moment arms

Poll Everywhere Which ST positions would increase sub-acromial impingement? - Downward rotation - Protraction - retraction - Upward rotation - Depression - Elevation

Answers: - Downward rotation - Retraction - Depression That would be b/c of the need of the shoulder blade to upwardly rotate and protract and elevate slightly when you are doing abduction - to get the acromion away from the humeral head and avoid impingement

- From anatomic position and in elbow flexion, you have a carrying angle - which we call a valgus- the proper term - so you have a valgus angle at the elbow joint As you come into elbow flexion b/c of that trochlea You are actually going into??

As you come into elbow flexion b/c of that trochlea - You are actually going into a bit of a VARUS

Figure 07-10. A, The transversospinalis group rotates the vertebrae by pulling the medial insertion (spinous process) toward the lateral origin (transverse process).

B, One point of confusion in the terminology occurs when the trunk "turns right" (anterior facing right) and the spinous process "moves left" (posterior facing left).

Elbow flexion ROM You can see the lateral epicondyle is circled here - The radial head is just distal to that This is a healthy person showing an average range of motion between 5 degrees beyond neutral extension through 145 degrees of elbow flexion - So this is the standard "normal" range of motion BUT a functional range of motion is only between???

BUT a functional range of motion is only between 30 and 130 degrees - Even though this is reported in the literature time and time again, it's well accepted that 30 degrees short of full extension is considered functional, it does come with some significant barriers to function in some people's lives Ex. When you have a 30 degree extension contracture, you can't weight-bear on your elbow as well, you can't reach as far and it can be very challenging to do various things

Closed Chain rotation - The radius becomes the fixed structure!! - The ulna becomes the MOBILE structure

Because of how weight-bearing works, when you do closed chain activities with your palms on the floor, what you are doing is most of the weight is being loaded on the radius because of the greater surface area at the distal end of the radius - That cause the radius to become wedged between your palm and the elbow and that allows the ulna to become the MOBILE structure So when your forearm is straight and you are in anatomical position,

Dislocated Elbow - dislocations occur easily, especially in children ---why is this?

Because of the loose capsule we talked about at the proximal radioulnar joint (PRUJ) dislocations occur pretty easily especially in children who generally already have laxity in their ligaments - radial head dislocation- pretty common when parents or someone grabs a kid by the forearm

Median nerve • Moves anterior in arm - So it stays close to the biceps, traverses kind of medial to the biceps and then enters the forearm

Between the two heads of the Pronator teres when it enters the forearm - That's how the pronator syndrome is named- if you are overusing your pronator forearm muscles or if they are too tight, then you can get pronator syndrome

In the carpal tunnel, You also have the median nerve going through there and you have the radial artery as well not shown

Can be the close quarters of the carpal tunnel that causes compression of the median nerve OR it can be because of a TIGHTENED transverse carpal ligament or flexor retinaculum - So if that ligament just tightens because of genetics, age, other factors, that can impinge on the median nerve even if there is not repetitive overuse of those tendons

The most well-known of peripheral neuropathies= carpal tunnel

Carpal Tunnel • The carpal tunnel contains a large number of important neurovascular and tendinous structures that pass through to the hand - You have all of the flexor tendons to the hand (all your FDS and FDP tendons) • Carpal Tunnel Syndrome (CTS) - Because of such close quarters, CTS is compression of these structures, especially median nerve, due to swelling and inflammation

Carpal Tunnel • The carpal tunnel contains a large number of important neurovascular and tendinous structures that pass through to the hand - You have all of the flexor tendons to the hand (all your FDS and FDP tendons)

Carpal Tunnel Syndrome (CTS) - Because of such close quarters, CTS is compression of these structures, especially median nerve, due to swelling and inflammation It becomes very relevant to consider with repetitive flexion or overuse of your grip ***You also have the median nerve going through there and you have the radial artery as well not shown

Clavicular elevation and depression - Basically shrugging your shoulder and dropping it down - This is occurring around an anterior-posterior axis of motion Clavicular protraction and retraction??

Clavicular protraction and retraction - Occurs around a vertical axis of motion - This is like when you pull your shoulder forward like you are going to round your shoulders into really bad posture - And also when you push your chest forward and your shoulder blades back - Could attempt to measure that via a birds eye view - Protraction is also going to occur a little bit with elevation and retraction with depression - So these are pretty hard to isolate all together

Articulations • Metacarpophalangeal (MCP) Ligaments 2. Collateral ligaments

Collateral ligaments= very important - A FAN-SHAPED ligament - It has certain fibers tight throughout the range - But the most important part here is collateral ligament is tightest when the MCP joints are in full flexion

Review and application • How would you expect someone who has limited forearm supination to compensate for their loss?

Compensating for lack of supination involves Shoulder ADDUCTION and lack of pronation involves Shoulder ABDUCTION - When you go into supination, but you only get maybe 20 degrees of supination, what you have to do to get more palm up is horizontally adduct your arm!! Your shoulder is going to come across your body- this is going to allow your hand to sit in a more palm-up position - The opposite is true if you are lacking PRONATION- you are going to perform Shoulder ABDUCTION- bring your elbow OUT from adducted next to your body which will appear like a pronated position but you are just compensating

Forces Acting on the Head and Torso Imagine that your vertebral column is a series of boxes with water balloons in between each box.

Compression of the column would cause the balloons to squish.

Shoulder complex abduction • The critical phase 30 -130 degrees:

Coordinated effort of shoulder abductors • Both scapular muscles and GH muscles are causing motion at approximately an equal rate • The humeral head is rotating in the glenoid fossa ***remember, this involves the concave-convex rule, convex humeral head rotating in concave glenoid fossa - motions are opposite - So inferior slide and roll here with shoulder abduction

Nerve Injuries Around the Elbow The cubital tunnel is bordered by the medial epicondyle of the humerus, the olecranon process of the ulna and the tendinous arch joining the humeral and ulnar heads of the flexor carpi ulnaris* - The ulnar nerve runs between those two heads

Cubital tunnel syndrome is the irritation or compression of the ulnar nerve while passing through the cubital tunnel

ECRL is a stronger radial deviator than ECRB

ECRB is a stronger wrist extensor than ECRL

ECRL is a stronger radial deviator than a wrist extensor

ECRB is a stronger wrist extensor than a radial deviator

Muscles of the elbow complex Elbow extensors lie anterior or posterior to the elbow axis

Elbow flexors lie anterior to the elbow axis Elbow extensors lie posterior to the elbow axis Elbow Extensors - Triceps - Anconeus

Muscles of the elbow complex Elbow flexors lie anterior or posterior to the elbow axis

Elbow flexors lie anterior to the elbow axis Elbow extensors lie posterior to the elbow axis Elbow flexors - Biceps - Brachialis - Brachioradialis - Pronator teres

Even though this is reported in the literature time and time again, it's well accepted that 30 degrees short of full extension is considered functional, it does come with some significant barriers to function in some people's lives

Ex. When you have a 30 degree extension contracture, you can't weight-bear on your elbow as well, you can't reach as far and it can be very challenging to do various things

Natural Curves of the Spine • The natural curves can change for reasons such as poor posture and abnormal pelvic positions kyphosis, lordosis, and scoliosis

Exaggerated posterior thoracic curve (Kyphosis)- like humpback • Exaggerated anterior lumbar curve (Lordosis) • Deformity of vertebral column in all three planes, most notably in frontal and horizontal planes (Scoliosis)

Which muscle is the STRONGEST WRIST EXTENSOR?

Extensor carpi radialis brevis- STRONGEST WRIST EXTENSOR- right next to the ECRL attaching to the third metacarpal base You see the ECRB being a really great wrist extensor, but not as good as a radial deviator as extensor carpi radialis longus

Restricting Forearm Rotation It is actually hard to restrict forearm rotation - Try to imagine how a cast or brace would stop forearm rotation

Following wrist fractures or other injuries, many individuals self-restrict rotational motion resulting in stiffness after cast removal A cast or brace must include the ELBOW to effectively block forearm rotation - This is called a Muenster Brace- a cast that includes the wrist AND elbow

The Foot & Ankle • Feet support the body weight in part through the transverse and longitudinal arches, which together form the hollow between the heel and ball of the foot.

Foot arch concept • Shock absorber • Energy storage (spring-elastic) • Tripod stance (stable on uneven ground) • Height of arches: Balance of load & weight bearing capabilities (arch flattens in overweight individuals)

Functional ROM for forearm rotation is?

Functional ROM for forearm rotation is between 50 degrees of supination and 50 degrees of pronation - but they are taking into consideration that you can use your shoulder to compensate and that's why you are going to generally be able to do most Activities of daily living (ADL)

As your COG changes, your hips adjust Gravity flexes your hips when UE COG falls where?? and extends your hips when UE COG falls where??

Gravity flexes your hips when UE COG falls anterior to the frontal plane, extends your hips when UE COG falls posterior to the frontal plane

Articulations Between Radius and Ulna Proximal radio-ulnar joint (PRUJ)

Head of radius (medial aspect) articulates with the radial notch (lateral aspect) of the ulna You can sort of feel it if you grip your radial head The radial head just spins in the shallow joint on the ulna in a pivot type joint The loose capsule allows rotation and minimally prevents dislocation of the radial head

Nancy uses less back-extensor force by supporting her body weight with one arm on the countertop.

Her upper-extremity muscles share the weight of her upper trunk, generating less compressive force. As Nancy raises the washcloth to her face, her need to flex decreases - So If we actually use less extensor force by supporting one arm on the counter top, it's going to save her back a lot - The other thing you can do is include a stool under this kind of sink and put one foot up on the stool which not only increases your base of support and throws your COG projection over your base of support which makes you a lot more stable, this also will allow the muscles in your legs to support you and help you with the body weight and take some pressure off the low back

Essex- Lopresti injury Only identified at time of injury in about 20% of cases

High impact fall on hand resulting in radial head fracture and interosseus membrane disruption Don't have to memorize this too much - basically this is when one has a high impact fall on the hand and it results in a radial head fracture and disrupts the interosseus membrane too because that radius was pushed into the humerus so hard that that compression force we just learned stretches the interosseus membrane pulls the fibers apart - it's also difficult to diagnose

Hip Adductors are

Hip Adductors are: Adductor longus, brevis and magnus (anterior head)

Movements and muscle use: Hip • Flexors include the

Hip flexors include the rectus femoris, sartorius, pectineus, tensor fasciae latae, and iliopsoas

BANKART tear

If there is a trauma or an excessive external force the humeral head as it dislocates inferiorly, can cause the inferior lip of the glenoid to FRACTURE - You can see the bottom lip of the joint is very small and could easily crack or fracture off

Joint Mobilization - Traction takes up all the slack in the capsule and won't allow additional movement - We want to perform joint mobilizations with a LOOSE capsule

If you add traction to a joint, you are basically treating it like a Chinese finger trap - When you pull your fingers apart, you are taking up all of the slack in that structure so you can no longer move anymore - So you put your fingers in and there is such a tight fit that it doesn't allow your fingers to come out - It took up all of the excess space with the fibers If you put traction on a joint and then try to do side to side motion to restore normal arthrokinematics or try to do a roll and a glide - It can't happen because you already took up all that space in a joint - So we want to perform joint mobilizations with a LOOSE joint capsule

If you don't have full elbow motion, you can't really reach out as far---this is important especially when??

If you don't have full elbow motion, you can't really reach out as far to catch yourself from falling if you are falling off a cliff

Impaired rhythm • Once the rhythm changes, problems can occur - - Impingement - - Inflammation - - Pain - - Subluxation - - Dislocation

Impaired rhythm- Scapulohumeral rhythm is basically the same thing as saying that there is a dyskinesia - Research has shown that 100% of people with impingement have a scapular dyskinesia - So they have impaired scapulohumeral rhythm and that can lead to impingement, inflammation, pain, subluxation, and dislocation

What about ligaments? Throwing: Tension on UCL Focus on the ulnar collateral ligament- UCL on the medial side

In a throwing athlete, the UCL is going to be more strained, there will be more stress and strain on this ligament because the weight of the hand and the weight of the ball and forearm is sort of coming to a fulcrum or axis at the elbow - So you would expect that the shoulder and the other muscles that are stabilizing around the arm are activating here and that is TRUE - But when you are going from this phase of a fully externally rotated position, and you are about to change directions, is when there is a lot of acceleration and deceleration happening - And that stress goes directed right at the medial side of the elbow

• If you think about leverage, what's wrong with this full bodied above the elbow cast?

In terms of leverage, you can see that the resistance arm that is down in the distal part from the fingers all the way to the elbow as the axis point - It's pretty long right? So if it's working against a very short effort arm being the upper portion of this just above the elbow, when you are trying to extend your elbow, what's going to happen? - You're going to get the dorsal side of this cast digging into the arm - Same thing if you are trying to bend your elbow into flexion, you will get the anterior part of this cast digging into the front of your arm So in terms of leverage, it is better to bring the proximal aspect as close to the armpit as possible so that you have an even distribution in terms of leverage

Introduction • The continuum theory states

Introduction • The continuum theory states that if ONE part of a nerve is compressed, strain is increased in other parts • NOTE: NERVES DON'T LIKE STRETCH OR STRAIN - So nerves really don't like stress or strain, they like GLIDE!!!

Balance at the hip • Try this: - Stand on one foot, lean on the weight bearing leg, shifting gravity's projection lateral to the abduction/adduction axis - Feel the isometric contraction of hip adductors in the medial thigh

Isometric contraction of the hip adductors balances gravity's abduction torque (abduction moment) at the front-to-back hip axis.

Important principles: - Nerve squeezing between two heads of a muscle

Nerve squeezing between two heads of a muscle- and how contraction or stretching of that muscle can increase the tension on the nerve - Diving under a muscle, or between two different muscles- want to consider this during normal daily activities

Important principles: - Nerve's own mechanics turn against it (like pulleys)-

It's own mechanics turn against it (like pulleys)- nerve mechanics how it travels from its origin to its insertion Important principles • Pulleys: - Maintain nerve or tendon position against skeleton- keeps everything really close and protected - Generally improve efficiency during movement by limiting bowstringing

The Lower Extremities • LE- ground the body to the earth through

LE- ground the body to the earth through a kinematic chain including the hip, knee and ankle

Lateral flexion= bringing your ear to your shoulder

Lateral flexion= bringing your ear to your shoulder and pure lateral flexion motion would not involve raising your shoulder up to your ears - So make sure not compensating with that Can attach goniometer to a patient's head - To measure cervical spine range of motion

• The long head of biceps tendon is intracapsular but extrasynovial

Long head of the biceps is like in the previous picture shown of the cadaver - It goes into the capsule of the shoulder

End Feel End feel is really important when evaluating someone Loose end feel is like what?

Loose end feel is SOFT and forgiving - This would be a concern for hypermobility/laxity of the ligaments - OK to try and stiffen these people with immobilization - (make sure patients understand WHY they are being immobilized) - VITAL to strengthen the muscles surrounding the joint for STABILIZATION (need a really strong surface to launch something off of- need stability of all proximal joints in order for distal joints and muscles to function normally and exert forces - Also important to teach a person to avoid extremes of motion and improve proprioception So with a person who has loose joints- often put in a cast and explain you need the joints to be stiff - That will help them with stability and feel stronger - People with hypermobility syndromes often don't know where their joints are in space - So the muscles really have to take on most of the proprioceptive input with neuromuscular retraining helps with that

Wheelchair adjustment • Low footrests- causes?

Low footrests - Place excessive pressure on the posterior thigh, and promotes posterior pelvic tilt High and low footrests promote development of pressure sores • Correctly adjusted footrests place hips near 90 degrees and posterior thigh is contact with the seat and feet rest in neutral position

Mary tries to stand from an erect sitting posture. Her quadriceps produce 316.8 kg of force to balance the downward pull of gravity on the upper body. Mary leans forward before standing.--what happens with this?

Mary leans forward before standing. Her quadriceps produce 211.2 kg of force to balance her upper-body weight.

Sense information about constant pressure

Merkel cells

So the axis is L5, L6- the L5 disk We increase the moment arm for the bigger box

Moment arm for body weight is negligible b/c sitting on top of spine- more of a compressive force - Not something we need a moment arm for • The larger box (same weight) nearly doubled the compressive force on the L5-6 disk

"The anatomic features of GH joint contribute to a design that favors mobility at the expense of stability." (Neumann, 2017)

Most of the time, people think of the ball and socket (glenohumeral joint) as your shoulder - But remember it's a lot more complicated than that - GH joint sacrifices stability for mobility

Scaption • Scaption- movement involving??

Movement of the upper extremity in the plane of the scapula (scapular plane) • This is an oblique plane, 30° to 45° anterior to the frontal plane 30º-45º

Joint Mobilization When joints are stiff or contracted, manual therapy is necessary to regain motion - This is because its often hard for a person to stretch their own joint capsule in a lot of cases

Must refer back to the concave-convex rule and know the ARTHROKINEMATICS! if the proximal joint segment is CONCAVE, the moving segment goes OPPOSITE the direction of the motion if the proximal joint segment is CONVEX, the moving segment goes the SAME direction of motion

Scapulothoracic (ST) "joint" and AC joint- are these true joints?

NO! not a true joint - Is not a true synovial joint because it has no joint capsule

Clinical Pearl • When a hip replacement is done through a posterior approach, the post-op restrictions include:

No flexion beyond 90 degrees - No internal rotation - No crossing the legs (adduction) • This is the location the hip is most likely to dislocate due to posterior ligaments being cut and repaired during surgery • If the hip dislocates, the patient must go back to surgery

Which carpal bone is considered to be a sesamoid bone?

PISIFORM - Actually a floating bone that is NOT considered part of the proximal carpal row anymore - now we just consider it to be a SESAMOID bone Hamate: just behind the pisiform

Movements and muscle use: Knee • Posteriorly, the hamstrings act as?

Posteriorly, the hamstrings flex the knee.

Scapulohumeral rhythm Going back to the setting phase (first phase): - The scapula stabilizes - Primarily the GH joint moves with use of the supraspinatus

Primarily GH moves while the scapula stabilizes - This refers to "setting" the humeral head into the glenoid fossa - This is accompanied by depression of the humeral head (inferior translation)

"Never Lose an Arm" Video - Amputee training with full arm prosthesis - Hook body powered - Practicing elbow extension - Cannot go back too far that elbow "locks" - Coming straight up straight down gets the motion back

Prior patient of Nikki's who is using a prosthetic device with a hook - Had an amputation at the level of his elbow - The man continues to repeat "Never Lose an arm" when he talks to anyone

Pronation and Supination Pronation muscles and supination muscles

Pronation - Pronator teres - Pronator quadratus Supination - Biceps - Supinator The brachioradialis pulls the forearm toward neutral, operating as both a supinator and a pronator

Subtalar (Talocalcaneal) joint • Between the talus superiorly and calcaneus inferiorly what motion occurs at this joint?

Pronation/supination occurs at the subtalar joint

5 Finger Trick for Medial Muscle Group - Thumb: pronator teres - Index: flexor carpi radialis - Middle: palmaris longus* - Ring: flexor digitorum superficialis - Small: flexor carpi ulnaris

Put the base of your thumb on your medial epicondyle - you want to splay your fingers out over your forearm - Thumb is in same place as pronator teres, index goes right over the flexor carpi radialis which is going to attach more at the base of the thumb, the middle finger is going to be over your palmaris longus (this is easy to remember because it is your long finger and palmaris longus- only present in 85% of population so you want to keep that in mind), Ring finger is over flexor digitorum superficialis, and the small finger over the flexor carpi ulnaris Keep in mind, this is only some muscles of the superficial group that we are talking about here

The rotator cuff • Four muscles comprise the rotator cuff - Supraspinatus (S) - Infraspinatus (I) - Teres minor (T) - Subscapularis (S)

Rotator cuff and GH stability • SITS muscles blend with GH capsule and provide dynamic stabilization of GH joint • Infraspinatus, Teres minor and Subscapularis (ITS) muscle horizontal force component compresses head of humerus against glenoid fossa

Rotator cuff • The tendons of the four muscles form a "cuff" around the head of the humerus • They help stabilize the joint and secure the humeral head into the glenoid fossa

Rotator cuff muscles • These muscles work together, complimenting and opposing each other and the other muscles of the GH • Supraspinatus, along with the deltoid abducts • Infraspinatus, teres minor and subscapularis adducts • Infraspinatus and teres minor externally rotate • Subscapularis internally rotates- but also works with the pec muscles to do the same

Can feel this muscle often on the medial part of your clavicle - SCM forward flexes and rotates - So it has a dual action SCM by itself, can also produce

SCM by itself, can also produce extension of the head and compression of cervical vertebrae - b/c muscles tend to move the lightest segment first toward the other insertion, its going to shift your head, not your whole torso and lower body

Talking about the metacarpals, distal carpal row, proximal carpal row and the forearm bones - When talking about the intercalated segment or the mobile proximal carpal row When you do a compression force of this, especially if there is an injury, you are going to get this effect that is sort of like when a train crashes - When there is a compression force and there is not a strong fixation between all of the segments, then you are going to have an instability

So the forces then cause ligaments to disrupt and because of the arthrokinematics you get this effect where the proximal carpal row shifts one way and the distal carpal row shifts the other way and therefore ligaments are strained and reach their yield point and snap

How does this change movement? Analyzing fractures on X-ray is not above and beyond what we do - But be hesitant about disclosing fracture findings with patients - This isn't generally our scope of practice But a good idea to figure out what stressors are located around the fracture site We should be looking at a fracture and try to determine which muscles attach around that attachment site and therefore, can help us plan our exercise program so we're not allowing muscles that attach near the fraction site to activate too much which could cause a shift in fracture fragments

So we don't want to potentially displace anything when we are evaluating fractures like this - But getting some of the muscles moving and working again and also if you can strengthen the right muscles you can get the fracture to heal better while bringing blood flow to the area and get other benefits from ROM and exercise

A, Scapular protraction and winging would occur if the serratus anterior inserted on the scapula's lateral border. B, Its actual insertion on the vertebral border holds the scapula close to the thoracic wall during protraction.

So when you are performing protraction, serratus anterior is the prime mover - Serratus anterior attaches along the medial border of the scapula - And it goes around the ribcage and attaches on ribs 1-9 So when using this muscle, it slides the scapula around the ribcage- which is called protraction b/c the serratus anterior attaches to the medial border, it also holds the scapula against the ribcage - So if someone is winging - it's most likely an indication that the serratus anterior is weak or paralyzed - A lot of researchers say that "True winging" occurs only when the long thoracic nerve is actually paralyzed or not functioning - which would prevent the serratus anterior from working

So when your arm is just sitting at the side, the upper portion of the capsule is taut or lax??

So when your arm is just sitting at the side, the upper portion of the capsule is taut- helping to maintain that position - So that the humerus just doesn't slide out and down There's an axillary pouch- that's the inferior part of the capsule -also called the inferior glenohumeral ligament- this inferior glenohumeral ligament is really important when you are doing ABDUCTION - It serves as a SLING to the humeral head - Can see this on the lower Right picture - As you raise your arm up, the upper portion of the capsule becomes slack, and the lower portion prevents the subluxation of the humeral head off the inferior portion of the joint

Subluxation is also called a Sulcus Sign

Subluxation is also called a Sulcus Sign- so when the humeral head slides down b/c of an instability or laxity in the superior capsule - A sulcus sign is positive when you can see a little bit of a cave- sort of like a divot right b/w the acromion and humeral head and if you can fit 1 to 2 fingers b/w the acromion and humeral head ***Remember, instability can also occur b/c of general laxity - some people are just more unstable than others- so it does have a genetic predisposition

Radial Nerve • Superficial branch travels along the radial side of the forearm to the wrist

Superficial branch of the radial nerve actually divides off after the nerve enters the forearm - It then traverses along the radial side of the forearm to the wrist

Wrist • Much more than just a connection of the hand to the arm - The wrist provides fine adjustments for hand placement and contributes significantly in hand grasp and manipulation

Synergistic actions of the wrist muscles working with the finger flexor and extensors position the long finger muscles in an optimal length-tension range (using that tenodesis) for forceful, effective prehension In your readings it said, exactly how much force there is when you are at 35 degrees of wrist extension

Synergistic Motions • Synergy is defined as:

Synergy is defined as: - Muscles acting together to produce specific movements • Back extension occurs through a synergy of muscle contractions • Most motions of the body are synergistic

The "TRUE" elbow joint has how many degrees of freedom?

The "TRUE" elbow joint only has 1 degree of freedom- flexion and extension

GH abductors • Along with scapular adduction and upward rotation of the scapula The GH abductors are:

The GH abductors are: - Deltoid - Supraspinatus - Biceps, long head

What about ligaments? - Lateral collateral ligament complex supports the elbow during flexion - More tension during passive internal rotation of the shoulder

The Lateral collateral ligament (LCL) is also known as lateral ulnar collateral ligament- that is because the Lateral collateral ligament (LCL) complex actually has a radial and an ulnar component - So the lateral ulnar collateral ligament is on the OPPOSITE side of the ulnar collateral ligament (UCL) on the lateral side

The PRUJ is a really LOOSE capsule, because???

The PRUJ is a really LOOSE capsule, because it is allowing for rotation - If the annular ligament was too tight, it would not allow the radial head to move

The annular ligament- function?

The annular ligament- holds the radius in place so that it can really just spin during pronation and supination Feel the olecranon process on the dorsal side of the elbow- feel for the groove SUPERIOR to the olecranon - May come in handy when trying to facilitate flexion - You can actually push on the olecranon in this area to help it glide the way it is supposed to

Median Nerve • Branches from the lateral cord of the brachial plexus • Continues under pec minor

The axillary artery is seen in red in the picture- that is how each of the cords is named- so lateral branch is on the lateral side of the axillary artery, medial is on medial side of the artery

Axes 1. Where would the axis for the humero-ulnar joint be located?

The axis would be approximately through the epicondyles. You would select a central point that the ulna rotates around

Which forearm muscle acts as both a pronator and supinator?

The brachioradialis pulls the forearm toward neutral, operating as both a supinator and a pronator Brachioradialis is on the radial side of your upper forearm - It serves as an elbow flexor, but also serves as a pronator AND a supinator because it brings the forearm to a neutral position

The lower trapezius and latissimus dorsi are shown indirectly elevating the ischial tuberosities away from the seat of the wheelchair

The contraction of these muscles lifts the pelvic-and-trunk segment up toward the fixed scapula-and-arm segment

Interosseus Membrane Holding a load, such as a suitcase, places a distal-directed force predominantly through the radius the distraction does WHAT to the interosseus membrane?

The distraction slackens the interosseus membrane any force that the ulna does take on, remember the interosseus membrane is PUSHING that force onto the radius - so most of the force is coming through the radius when you are holding a load - but the distraction actually slackens the interosseus membrane

Glenohumeral stability Static GH stabilizers

The glenoid labrum is like a suction cup The capsule is a ligamentous structure that kind of secures the entire joint- the capsule is around the entire joint

Loss of Supination Imagine that your patient was casted for a very long time in forearm pronation --how does this impact the interosseus membrane?

The prolonged position that allowed laxity in the interosseus membrane also caused it to SHORTEN Following cast removal, your patient is unable to supinate beyond "forearm neutral" - Remember supination is the maximum stretch position of the interosseus membrane so it makes sense that when you cast someone in a prolonged pronated position- this is where the interosseus has some slack on it - If you immobilize the arm in this pronation, then it causes the fibers to SHORTEN - So now the person cannot go into a supination position

Radial Nerve • Anterior to subscapularis, latissimus dorsi and teres major • Dives toward the dorsal arm through the triangular interval (quadrangular space)

The radial nerve actually enters into the quadrangular space Radial nerve goes through this space as it dives towards the triceps

Radial Nerve Injury at the Elbow The radial nerve can also be compressed under the supinator and is called radial tunnel

The radial nerve can also be injured with distal humeral fractures, resulting in radial nerve palsy - Commonly presents with wrist drop - person is unable to extend their wrist against gravity

Radial Nerve • Travels obliquely to Enter the spiral groove of the humerus • A common place of trauma due to humeral shaft fracture

The radial nerve continues down the upper arm and enters the spiral groove of the humerus which is then a common place for the radial nerve to be injured when you have a humeral shaft fracture - With proximal humeral shaft fractures the axillary nerve is going to be more likely damaged - With mid-shaft fractures, the radial nerve is more likely to be damaged The radial nerve spirals around from dorsal to volar so that it can enter the forearm

Forces Acting on the Head and Torso Figure 07-19. To maintain the head at a 30-degree angle, the erector spinae muscles must exert a force of 7.5 kg The reaction force increases accordingly.

The reaction force increases accordingly. With the head at 30 degrees, most of the weight exerts a compression effect on the vertebral column, and the compression from the erector spinae contraction increases compared to the erect position. The reaction force (at least 7.5 kg) exerted toward the head equals the sum of the two forces directed toward the shoulders (7.5 kg plus a portion of the head's weight). As before, these two forces consist of the muscle contraction force and the portion of the head weight directed into the cervical disk (B).

Glenoid labrum

The rim of the glenoid fossa is augmented by a thick fibrous cartilage called the glenoid labrum **** The labrum does not cover the inferior lip, which is shallow to allow adduction • In the shoulder, the glenoid labrum extends out to the joint capsule to add stability to the shallow glenoid fossa - The glenoid labrum deepens the "socket" by 50% - Adds about 20% to the stability of the GH Remember the glenoid labrum is really like a suction cup- it sucks the humeral head into the glenoid fossa

• Peripheral nerves adapt to the movement of joints - So when you extend your wrist, you are causing a slide of the median nerve DISTALLY - So basically its your fingers and your hand that is causing a DISTAL glide of the median nerve The same is true when you go PROXIMALLY

The same is true when you go PROXIMALLY, so when you bend your elbow, your median nerve is becoming slack at the elbow joint - If you bend your wrist it is also becoming slack or moving just proximally compared to when your wrist is in neutral So of course, your shoulder and neck, all of those joints that each nerve crosses, have an effect on nerve excursion

Forces Acting on the Head and Torso Figure 07-17. To maintain the head in erect posture, the erector spinae muscles must exert 2.5 kg of force. This causes a reaction force of 7.5 kg upward on the C5 disk, determined by adding the two forces (head weight and muscle force) directed downward - In an erect position, we are going to look at: - Using 5kg for the mass of the head - 2.5 kg for the neck muscles pulling down on the dorsal side of the head

This causes a reaction force of 7.5 kg upward on the C5 disk - Basically just by adding those two weights

Radial Nerve • Superficial branch • When irritated, usually from Shear forces, is called Wartenberg's Syndrome

This is also known as Watchband syndrome because people who wear a really tight watchband can irritate this nerve- that's how close it is to the surface, right at the point where you would be wearing a watch - It can also be irritated from a lot of repeated radial ulnar deviation and it can be injured by trauma when wearing handcuffs

Each tendon's moment arm has a radial/ulnar deviation & flexion/extension component

This is showing how extensor carpi radialis longus (ECRL) has a greater wrist radial deviation component than ECRB The ECRB is a better wrist extensor compared to ECRL

Kinetic Chain - What happens to the shoulder during activities when an elbow flexion contracture occurs?

This is showing the differences in your ability to reach when you have an elbow flexion contracture of 30 degrees - So the outside arc is showing how far you could reach if you have full extension - The inside arc is showing how far you can reach if you have 30 degrees of flexion contracture at the elbow Whether or not this is significant depends on the environment in which you are working

Loose end feel is SOFT and forgiving - This would be a concern for?

This would be a concern for hypermobility/laxity of the ligaments - OK to try and stiffen these people with immobilization - (make sure patients understand WHY they are being immobilized) - VITAL to strengthen the muscles surrounding the joint for STABILIZATION (need a really strong surface to launch something off of- need stability of all proximal joints in order for distal joints and muscles to function normally and exert forces - Also important to teach a person to avoid extremes of motion and improve proprioception So with a person who has loose joints- often put in a cast and explain you need the joints to be stiff - That will help them with stability and feel stronger - People with hypermobility syndromes often don't know where their joints are in space - So the muscles really have to take on most of the proprioceptive input with neuromuscular retraining helps with that

Torso Movements Muscle contractions in three major groups of muscles produce cervical, thoracic and lumbar movements - The abdominal flexors cause movements in which sections?

Thoracic and lumbar movements Muscles going up and down the spine

• This procedure evaluates the strength of the gluteus medius muscle on the stance side. • Ask the patient to stand on one leg.

Trendelenburg sign/ Gluteus medius test - If he stands erect, the gluteus medius muscle on the stance side should contract as soon as the opposite leg leaves the ground, and should elevate the pelvis on the unsupported side.

Carrying Angle - varus and valgus

Varus= distal part angles inward putting more lateral pressure on the joint Valgus= distal part angles outward putting more medial pressure on the joint Normal carrying angle 5-15-degree valgus - When the carrying angle is more than that, there can be a strain on the medial collateral ligament on the medial side of the elbow - It can also cause problems for your ulnar nerve - Your ulnar nerve is really designed to tolerate the 5 to 15 degrees of valgus angle but if its any more than that, it does put additional stress on the nerve as it crosses that elbow

• Splint fabrication should not ignore shape of the relaxed hand. - And for function - When your hand is a totally relaxed position you should be able to see these two arches

We want to maintain these arches when we splint the hand b/c if we lose the arches, we are no longer able to conform our hand around so many different shapes

Compressive Forces on the UE Joints - The same procedures we used to determine compressive forces in the joint for the low back can be used for the joints in the upper extremity

What its showing is the forces of the hand and the forearm depending on how much force is being exerted by the biceps

Compressive Forces • We can estimate the compressive forces on the intervertebral disks. • We know that the erector spinae muscles run parallel to the vertebral column. • When they contract they cause???

When erector spinae muscles contract they compress the intervertebral disks.

Restricting forearm rotation When fractures near the wrist require complete rest, rotation must be stopped Forearm rotation causes motion of both the radius and the ulna via the joints and primarily via the interosseus membrane. The ulna is most affected.

Wrist injuries that include the ulna nearly always involve casting or splinting of both the wrist and elbow. Radial wrist fractures alone rarely include casting the elbow - ex. Colles' Fracture knowing why you are doing something is really important to the profession!! And to your patients to show why these restrictions exist when you have a distal radius fracture, you don't always immobilize the elbow - it is also true that when a radial head fracture or dislocation occurs, there is a very brief immobilization period- b/c we don't want to block the elbow from moving!! Why is that?? - The elbow is so congruent and the bones are so close together that we don't want to have swelling occur and inflammation and then immobilization because when the swelling is there, it makes the joint really easy to stiffen up - For this reason, its really hard to get full elbow motion back

Brief Synopsis: Acromioclavicular (AC) joint about how many degrees of upward rotation in arm elevation?

You get 30 degrees of upward rotation at the Acromioclavicular (AC) joint

How many degrees of external rotation for full arm elevation at the GH join

You get 35-40 of external rotation requires for full arm elevation at the GH joint

• This is the location the hip is most likely to dislocate???

a posterior approach hip replacement This is the location the hip is most likely to dislocate due to posterior ligaments being cut and repaired during surgery

***Numbers will vary, but the thing to remember about the TFCC is that it absorbs forces through the wrist and??

and allows for a distribution of forces between the radius and ulna When the TFCC is damaged, then 95% of the load through the radius and ulna is brought onto ONLY the radius

Radial nerve neuropathy

around the elbow at the radial tunnel (the groove that is in the middle of the supinator muscle belly on the posterior side of your arm) Will notice the flexor carpi ulnaris for the ulnar nerve will cause impingement between those two heads we talked about - The supinator also has 2 heads- so it's important to note the radial nerve goes through a muscle that has two heads - The ulnar nerve also runs between a muscle that has two heads *This can become a problem for compression of that nerve

Elbow joint

articulation of the humerus and the ulna at the olecranon process - Form a hinge-type joint - One degree of freedom: flexion/extension

Muenster Brace- a cast that includes

cast that includes the wrist AND elbow It's actually really hard to restrict forearm rotation - Your forearm rotation is most effectively immobilized when you block the elbow AND the wrist- so proximal at the elbow and distal at the wrist Sometimes you can get a splint that crosses the elbow but allows elbow flexion and extension

. Bending at the knees allows Nancy to lower her face to the sink without bending her back. The weight of the upper trunk works at a smaller moment arm, and the back extensors produce a smaller contraction force.

helps a lot with decreasing the forces at the lower back - She keeps the lower portion of her back straight, thus decreasing the forces acting on her lower back as she bends over the sink.

Joint Mobilization Must refer back to the concave-convex rule and know the ARTHROKINEMATICS!

if the proximal joint segment is CONCAVE, the moving segment goes OPPOSITE the direction of the motion if the proximal joint segment is CONVEX, the moving segment goes the SAME direction of motion

Balance • As the body moves in and out of various positions, muscle groups in the lower extremity

muscle groups in the lower extremity continually respond to the body's changing center of gravity

Loss of Supination 5. What other structures should you check for tightness?

muscles, joint capsules, and ligaments

Important principles • The path matters - Crossing a joint

need to know how crossing a joint affects a nerve, especially when there is tightness in the nerve or a pathology

There are really simple ways of evaluating functional reach patterns during an inpatient or outpatient evaluation

outpatient evaluation - Ex. "show me how high you can reach your arms" - so just lift your arms over your head like you're doing a field goal or touch down motion - Then "I want you to touch your head" "Touch your low back" "Touch your feet" - This involves a lot of movements that are very functional If I wanted to check LE as well, I would have them cross their one leg over the other while sitting Also placing your hand behind your head is a very functional position - You use this with washing and combing your hair grooming - Then reaching behind your back you use for a bunch of things like tucking in your shirt, or string a belt through the loops

Articulations • Metacarpophalangeal (MCP) Ligaments 1. Volar plate

prevent hyperextension Volar plate prevents hyperextension beyond a certain point - Some people have tighter volar plates than others, but the MCP joints in general, do have the capacity to hyperextend - When you do this, you may feel a bit of tension near the metacarpal heads on the volar side of the hand - that's in part, due to the volar plate tightening to prevent hyperextension beyond that point

reach patterns • UE reach patterns depends on variety of scapular movements So here's a couple functional patterns: - Reaching the hand behind the back

scapular (ST) downward rotation, full GH internal rotation, shoulder extension and elbow flexion- and in most cases ANTERIOR tilting (the inferior border of the scapula lifts away from the ribcage or thorax) - This is a big motion for anterior tilting b/c a lot of people tend to rock their scapula forward using some of the chest muscles here - Very functional motion

Brief Synopsis: The sternoclavicular (SC) joint has about 25 degrees of elevation with full arm elevation At the same time, you get a little bit of sternoclavicular joint retraction

sternoclavicular (SC) joint has about 25 degrees of elevation with full arm elevation At the same time, you get a little bit of sternoclavicular joint retraction - 20 degrees- - SC joint posterior rotation of 25 degrees - The clavicle retracts a little bit and glides downward in the sternoclavicular joint resulting in elevation of 25 degrees

Dislocation • Dislocation of a joint occurs when it is pulled out of its joint space and cannot be easily reduced

this means that the humeral head is going to fall off COMPLETELY from the glenoid - Can see in the first picture when the humeral head is attempting to abduct, it's supposed to slide down in the joint - If there is a trauma or an excessive external force the humeral head as it dislocates inferiorly, can cause the inferior lip of the glenoid to FRACTURE- BANKART tear - You can see the bottom lip of the joint is very small and could easily crack or fracture off

In Wrist ROM -you are going to have more motion in ulnar deviation OR radial deviation?

you are going to have more motion in ulnar deviation than radial deviation!!! - People always question what is normal for a recovery after a wrist injury- so it is normal to have more ulnar deviation than radial deviation - It's important to inform your patients of what is normal so they understand what to expect after an injury or surgery Of course a lot of surgeries lead to changes in what is expected for ROM afterwards - But they should generally have less radial deviation than ulnar deviation

Joint kinematics of the glenohumeral (GH) joint GH abduction and adduction

you get a roll and slide along the joint's longitudinal diameter - This is where you get the inferior roll and slide while you are going into abduction of the shoulder

Glenohumeral stability • The GH joint is made stable by STATIC and DYNAMIC stabilizers

§ Static stabilizers 1. Glenoid labrum 2. Glenohumeral capsule § Dynamic stabilizers 1. Rotator cuff muscles

Pure Wrist Motion • Pure wrist motions like flexion occur only with activation of paired wrist muscles • Activation of FCR and FCU cancels out which motions and produces what?

• Activation of FCR and FCU cancels out radial and ulnar deviation and produces balanced flexion

Pure Wrist Motion • Pure wrist motions like flexion occur only with activation of paired wrist muscles • Activation of FCU and ECU cancels out which motions and produces what?

• Activation of FCU and ECU cancels out flexion and extension and produces balanced ulnar deviation

Gastrocnemius • Besides plantaris muscle, WHAT is the only muscle that crosses both knee and ankle joints+

• Besides plantaris muscle, gastrocnemius is the only muscle that crosses both knee and ankle joints+ • Gastrocnemius quickly weakens as a knee flexor as the ankle is plantarflexed • Gastrocnemius produces the greatest amount of knee flexion torque when the knee is in full extension

Sternoclavicular (SC) joint • The SC is the only joint that attaches the upper extremity (UE) to the axial skeleton

• Clavicular elevation and depression occur around the joints A-P axis - 45 to 60 degrees of elevation and 5 degrees of depression • Clavicular protraction & retraction occur around the vertical axis - 15 degrees in both direction - Protraction occurs with elevation & retraction with depression • Upward and downward rotation of clavicle occur around the clavicle's longitudinal axis - 40 degrees of up rotation in shoulder flexion and abduction

Movements and muscle use: Hip • Open chain functions move the thigh in relation to the trunk at the hip joint • Closed chain movements adjust?

• Closed chain movements adjust the verticality of the trunk through their pelvic attachments

Scaption • Scaption emphasizes the length-tension relationship in the various GH muscles and provides a more favorable plane of motion so it is easier to move in this plane

• Combined with GH external rotation, scaption (or shoulder elevation) reduces the possibility of pinching the shoulder capsule between the humeral head and the acromion process with elevation of the arm (impingement) ***Here it says shoulder capsule, but it is really more than just the capsule - it's also the SOFT TISSUES

Open and Close Packed Positions • The three ligaments of the hip's anterior aspect have an oblique trajectory, winding around the femoral neck consequently they are loose or tight in extension and flexion?

• Consequently, they are loose in flexion (A), and tight in extension (B).

Radial nerve Branches from the posterior cord of the brachial plexus

• Continues dorsally under pec minor- stays more dorsal than the median and ulnar

Ulnar nerve • Branches from the medial cord of the brachial plexus

• Continues under pec minor

Transversospinalis • Small muscles that attach to the spinous processes and the transverse processes • The fibers run diagonal to the spinal column • Contraction causes what motion??

• Contraction causes spinal rotation - Based on vectors- as they pull, cause spinal rotation

Ulnar Nerve • After Guyons canal, the motor and sensory fibers separate to their respective innervations:

• Cutaneous to the small finger and ulnar half of the ring finger • Motor to the ulnar intrinsics: • Lumbricals 3-4 • Hypothenar (OAF) • Palmar and dorsal interossei, ulnar to radial • Flexor pollicis brevis (deep head) • Adductor pollicis

Foot "cardinal" motions • Dorsi/plantar flexion • Inversion/eversion • Abduction/adduction what plane and axis do these all run in?

• Dorsi/plantar flexion - sagittal plane and coronal axis • Inversion/eversion - Frontal plane and longitudinal axis - Plantar surface brought towards midline in inversion • Abduction/adduction - Transverse plane and vertical axis

Volar plate • On the palmar surface of MCP joint

• During flexion, the plate glides proximally down the volar surface of the metacarpal head. • Reinforces joint capsule • Enhances joint stability - along with extensor hood, especially sagittal bands and collateral ligaments • Prevent hyperextension • Prevents the long flexor tendons from being pinched in the joint.

Movements and muscle use: Hip • Extensors include the

• Extensors include gluteus maximus and hamstrings

Gait • Gait training is not actually in the OT scope of practice, but gait analysis can be helpful • Understanding mechanics of gait can provide insight into the patient's physical status that affect various areas of occupation

• For example: walking with a limp affects the lower body, trunk and upper body. If the hips drop down, the same shoulder will also drop down. but the patient will generally keep their head up to keep their vision centralized. This can strain the brachial plexus

Rotator cuff and GH stability • Supraspinatus has a horizontal compressive force

• Supraspinatus also has an upward vertical force that causes abduction. • This vertical force is balanced by gravity Supraspinatus has a horizontal compressive force- shown on the right are its upward and inward forces - Its resultant force is following its line of pull

Scapular motions • The scapula moves in six directions with or without GH joint involvement

• Full scapular motions require motion at the SC and AC joints • Scapular motions are necessary for full GH joint motion • Scapular motions are necessary for solid performance of upper extremity tasks these six scapular directions occur with or without GH joint involvement - But the full scapular movement DOES require motion at SC and AC joints - So remember that the shoulder girdle really doesn't work in terms of one joint at a time, it's really a combination of joints functioning together in unison

GH adductors • GH adduction occurs along with scapular adduction • GH adductors are:

• GH adductors are: - Pectoralis Major - Teres Major - Latissimus Dorsi

GH internal and external rotators

• GH internal rotators: - Pectoralis Major - Teres Major - Latissimus Dorsi - Anterior deltoid - Subscapularis • GH external rotators: - Infraspinatus - Teres Minor - Posterior Deltoid Review the insertion and origin of these muscles, look at the fibers and how they run so then we can determine the line of pull - Where does it go around the axis of rotation will give us the answer to the action of these muscles

Shoulder (continued) "Shoulder" motions - Scaption - Elevation via shoulder abduction

• GH joint stability - Subluxation - Dislocation

• Besides plantaris muscle, gastrocnemius is the only muscle that crosses both knee and ankle joints+ • Gastrocnemius quickly weakens as a knee flexor as the ankle is plantarflexed • Gastrocnemius produces the greatest amount of knee flexion torque when???

• Gastrocnemius produces the greatest amount of knee flexion torque when the knee is in full extension

Introduction • Proximal contributions on upper extremity function - ALWAYS, ALWAYS, ALWAYS screen for proximal dysfunction - Proximal mechanics change the entire kinetic chain!!

• If peri-scapular muscles are weak, the shoulder doesn't work right • If the shoulder is weak, smaller muscles are forced to work harder • If smaller muscles work harder, they fatigue more quickly • Muscle fatigue generally leads to injury

Trendelenburg sign/ Gluteus medius test • If the pelvis on the unsupported side actually drops, the gluteus medius on the stance side is

• If the pelvis on the unsupported side actually drops, the gluteus medius on the stance side is either weak or non-functioning (positive Trendelenburg sign)

Coordination of Motion • If the muscles on one side of the back contract, they perform lateral flexion • In order to perform back extension

• In order to perform back extension, muscles on both right and left side of back must contract. - The muscles oppose each other but due to the distance (although small) posterior to the axes of the vertebral joints, the combined contraction causes extension

Rotator cuff and GH stability • SITS muscles blend with GH capsule and provide dynamic stabilization of GH joint

• Infraspinatus, Teres minor and Subscapularis (ITS) muscle horizontal force component compresses head of humerus against glenoid fossa So it's really important to have a strong rotator cuff because they basically hug the humeral head into the joint from all angles - They really kind of start at your scapula, wrap around, and pull the humerus in - **But they only pull in if they are contracting at the right times

Acromioclavicular (AC) joint • The AC joint is the attachment of the distal clavicle to the acromion process of the scapula. • Is not a true synovial joint because it has no joint capsule

• Is not a true synovial joint because it has no joint capsule • Is supported by the AC ligament and the muscular attachments distal and proximal to the joint (i.e. the deltoid)

Articulations • MCP joints of the hand - type of joint and DF?

• MCP joints - Condyloid joints. - 2 degrees of freedom: flexion/extension, abduction/adduction.

Ulnar and Radial Deviation- plane and axi?

• Movement is in frontal plane • Around the anterior-posterior axis that passes through the capitate bone

Common Tendon Transfers

• Opponens plasties: - Huber: Abductor Digiti Minimi (ADM) to Abductor Pollicis Brevis (APB) insertion - Pronator Teres (PT) to Flexor Pollicis Longus (FPL) - Brachioradialis (BR) to APB insertion • For Radial Palsy: - BR or PT to Extensor Digitorum Communis (EDC) - BR or PT to Extensor Carpi Radialis Brevis (ECRB) - Palmaris Longus to Extensor Pollicis Longus (EPL) • Or Extensor Indicis Proprius (EIP) to EPL

Movements and muscle use: Knee • Quadriceps femoris acts as

• Quadriceps femoris acts as knee extensors (and hip flexors).

Primary scapular downward rotators

• Rhomboids major and minor and Pectoralis minor - Pectoralis minor attaches to the coracoid process of the scapula anteriorly - And the rhomboids which attach to the medial border, and because of the fiber direction, it is easy to see that they pull the scapula into retraction and downward rotation

Glenohumeral ligaments • Ligaments typically check or stop excessive motion in one direction (like a tether) while allowing motion in another direction

• SGHL: Superior glenohumeral ligament • MGHL: Middle glenohumeral ligament • IGHL: Inferior glenohumeral ligament • CAL: Coracoid acromial ligament • CCL: Coracoid clavicular ligament (- i.e. the inferior glenohumeral ligament stops the inferior glide of the humerus when it is fully abducted)

Shear Forces

• Shear forces are when the forces are parallel to the surface of the disk or when vertebral bodies are pulled across each other (or actually across the disk).

Foot arch concept--functions??

• Shock absorber • Energy storage (spring-elastic) • Tripod stance (stable on uneven ground) • Height of arches: Balance of load & weight bearing capabilities (arch flattens in overweight individuals)

Rotator cuff muscles • These muscles work together, complimenting and opposing each other and the other muscles of the GH

• Supraspinatus, along with the deltoid abducts • Infraspinatus, teres minor and subscapularis adducts • Infraspinatus and teres minor externally rotate • Subscapularis internally rotates- but also works with the pec muscles to do the same

GH extensors • GH extension occurs along with scapular adduction, medial rotation and elevation (and anterior tilt)

• The GH extensors are: - Posterior Deltoid - Teres Major - Latissimus Dorsi - Triceps, long head GH extensors occur in conjunction with scapular adduction, medial rotation, and elevation and anterior tilt

GH flexors • GH flexion occurs along with scapular abduction and upward rotation

• The GH flexors are: - Anterior deltoid - Biceps - Pectoralis major, upper fibers - Coracobrachialis As I said before, the scapula has to upwardly rotate- it basically has to shift out of the way so that the acromion does not cause an obstruction to the humeral head

Triangular fibrocartilage complex (TFCC) • The TFCC is a small piece of cartilage and ligaments on the distal end of wrist - It is on the ULNAR side of the wrist • The TFCC is formed by?

• The TFCC is formed by the - triangular fibrocartilage disc - the Meniscus homolog (really the same as the articular disc or fovea- called the meniscus homolog because it is really a shock absorber just the same as the meniscus in your knee is) - the ulnar collateral ligament - the ulnotriquetral and ulnolunate ligament, - radioulnar ligaments - the sheath of the extensor carpi ulnaris tendon, and - the capsule of the distal radioulnar joint

Gleno-humeral capsule

• The capsule arises from the glenoid fossa and inserts around the anatomic neck of the humerus • There is a synovial lining throughout that blends with the hyaline cartilage of the head of the humerus but fails to reach the cartilage of the glenoid fossa • The long head of biceps tendon is intracapsular but extrasynovial

Natural Curves of the Spine • The human vertebral column consists of a series of reciprocal curvatures within the sagittal plane • These natural curvatures contribute to ideal spinal posture while one is standing

• The cervical vertebrae form an anterior convex • The thoracic vertebrae form an anterior concave • The lumbar vertebra form an anterior convex • The sacro-coccygeal region forms an anterior concave

When we're talking about stretching a nerve, we are talking about the nerve being pulled from its origin to its insertion - If you know the path of the nerve, you know how to stretch every nerve in the whole body - All you need know is the path and imagine what happens when you move each of the joints the nerve crosses then you can figure this out pretty easily What's more difficult to figure out is??

• The elastic limit of a peripheral nerve - what is 7 to 20 percent of stretch?? - This is not something we can rely on in daily activities - We need to rely on scientific evidence to rely on how far is 7 to 20 percent stretch - Like what would be necessary to cause that Symptoms tend to occur before that limit

How much can a nerve stretch? Remember... nerves do not like to be stretched • The elastic limit of a peripheral nerve is??

• The elastic limit of a peripheral nerve is 7% to 20% of its normal length (kind of like the yield point) • Assessed using buckle force transducers • Symptoms tend to occur prior to that limit however (Topp & Boyd, 2006) Like the yield point, you can add tension to a nerve up until a certain point and then it is permanently damaged after that When we're talking about stretching a nerve, we are talking about the nerve being pulled from its origin to its insertion - If you know the path of the nerve, you know how to stretch every nerve in the whole body

Compression by the Erector Spinae • The compression force exerted on the intervertebral disks by the erector spinae is considered to be the same as the reaction force of the muscle - We calculate this from the joint moments

• The full compressive force on the intervertebral disk is the sum of the reaction force plus the weight of the body above the disk, and any other loads that would exert a downward force - • Compressive force on an intervertebral disc= Force due to body segment + Force due to external load being lifted + Force of erector spinae muscles

Gleno-humeral capsule • The tautness of the superior GH capsule with the arm dependent prevents downward dislocation of the arm

• The laxity of the GH superior capsule permits the gliding motion of the GH joint

Reconstruction Model

• The model is defined by: Use of voluntary activities, which are graded and adapted to specific muscles and joints to restore physical function after illness or injury - This is not a full umbrella term but it really fits with developing specific programs that are geared towards restoring physical function depending on what the person has going on - Also reminds us the importance of getting a good background and history of the issue - when did it start, was it a slow cumulative process or sudden onset, etc. - Helps us to investigate each structure independently helps us determine what is actually injured and develop a treatment program

Gleno-humeral capsule • With the arm hanging loosely in a dependent position at the side, the upper portion of the capsule is taut, and the inferior portion, the axillary fold, is loose and pleated (Fig. 10)

• The opposite situation exists when the arm is fully abducted

Radial Nerve Injury at the Elbow • The radial nerve can also be compressed under the supinator and is called radial tunnel.

• The radial nerve can also be injured with distal humeral fractures, resulting in radial nerve palsy - Commonly presents with wrist drop.

Protraction

• The scapula rides the rib cage laterally - Serratus anterior • Pulls the medial border of the scapula anteriorly • Prevents winging (medial border)

The shoulder complex (AKA shoulder girdle) involves 4 joints

• The shoulder complex or shoulder girdle comprises of set of four mechanically interrelated articulations involving the sternum, clavicle, ribs, scapula, and the upper humerus These 4 joints of the shoulder complex are: - - Sternoclavicular (SC) joint - - Acromioclavicular (AC) joint - - Scapulothoracic (ST) joint - - Glenohumeral (GH) joint

Muscular Spindle AKA: Muscle fibers --extra vs. intrafusal fibers

- Make up the muscle's belly - Intrafusal and extrafusal Intrafusal= sensory Extrafusal= motor output

Vertebral Column • All the vertebral bodies, except for the first two, attach via symphyses, cartilaginous joints containing intervertebral disks

• The structure of the vertebrae and the intervening disks form a STRONG, FLEXIBLE column capable of absorbing a great deal of shock without crushing the spinal nerves Vertebral canal is where your SC runs through and b/w vertebral bodies is where the spinal nerves project out of

The Torso • Torso provides a stable base for the attachment of the extremities and adds to their movement capabilities

• The torso, head, vertebrae, and pelvis accompany upper- and lower-extremity movements - Just a reminder that your core- your axial skeleton is really important for protection but also doesn't just sit still as your arms and legs move, the kinetic chain implies that as you use your uppers and lowers, you are going to have an effect on your trunk

Subluxation • Subluxation occurs when the humeral head slips down out of the glenoid fossa. (also called a sulcus sign)

• This differs from dislocation because it just slides there due to lack of support, and can passively be reduced, or manually put back in place. • Subluxation occurs partially because of instability of the structures superior to the joint - Superior glenohumeral ligament - Supraspinatus muscle contraction - Deltoid muscle contraction

The shoulder complex • The GH joint is the articulation of the humerus in the glenoid fossa. (glenoid fossa is part of your scapula) • It is less frequently described as scapulo-humeral joint.

• This is commonly thought of as the shoulder joint (***A lot more complicated than that) - It is a ball and socket joint - It is very mobile, allowing a wide arc of motion "The anatomic features of GH joint contribute to a design that favors mobility at the expense of stability." (Neumann, 2017)

Scapulothoracic (ST) "joint"

• This is not a true joint - It is the articulation between the anterior surface of the scapula and the posterior lateral wall of the thorax (basically it's the scapula on the ribcage)

Shoulder complex abduction • The final phase 140-180 degrees:

• Three times more GH motion than scapular motion (3:1 for GH: ST) • The scapula continues to provide essential stabilization for the humerus The scapula still needs to stabilize in order for this motion to happen even though GH joint has 3 times more motion than scapular motion - Stabilization of the scapula can seem a little confusing - Imagine you are prone- lying face down on a mat with your arm over the edge of a table - I want you to do a scaption movement- which is kind of like a "Y" position with your arms - So you are going into that diagonal movement

Hand Arches+ • Two arches that are oriented 90 degrees to each other.

• Transverse arch curves from radial to ulnar side. - Apex, or highest point lies near head of third metacarpal. • Longitudinal arch curves from wrist to the fingertips. - Apex is at the row of metacarpal heads. ***The two arches- the transverse arch and longitudinal arch INTERSECT • Splint fabrication should not ignore shape of the relaxed hand. - And for function - When your hand is a totally relaxed position you should be able to see these two arches We want to maintain these arches when we splint the hand b/c if we lose the arches, we are no longer able to conform our hand around so many different shapes

Primary scapular upward rotators

• Upper and lower trapezius • Serratus anterior (lower fibers) • Three different attachments on the scapula coordinate to upwardly rotate and position the glenohumeral fossa upward. • This moves the acromion out of the way to allow the humerus room to elevate.

During hip flexor weakness • Upright posture is maintained by doing what??

• Upright posture is maintained by locking knees and extending back- this is not good when you lock your knees, you change the circulation to the brain and that can lead to passing out ***Extension effect is balanced by the anterior hip ligament iliofemoral ligament - Basically when you extend your back, your iliofemoral ligament maintains your upright posture (small arrow on picture on the hip)

Wrist • Connection of the hand to the arm positions the hand so that the long flexors and extensors can grasp and release objects • Wrist is comprised of:

• Wrist is comprised of: - Distal radius, Ulnar disk (TFCC - triangular fibrocartilage complex) and 8 carpal bones • Various ligaments arrange the carpal bones into an arch - Convex on dorsal side and concave on the palmar side.

The Hand: Introduction • Extrinsic tendons transmit forces from the forearm to the hand, crossing 4 or more joints - This is when we talk about tenodesis and active and passive insufficiencies

•Most intrinsic muscles cross 2 or more joints • Fingers conform to a wide variety of shapes

Dynamic Labyrinth Response of the horizontal semicircular canals to head rotation in the horizontal plane

- At rest (A) the firing rates of horizontal canal afferents are equivalent on both sides - With a leftward head turn (B) or a rightward head turn (C), there is a receptor depolarization and afferent fiber excitation toward the side of the turn and corresponding inhibition on the opposite side Basically if turn your head to the L, will get an excitatory response b/c of the fluid that's going to help give info to brain about how fast you were turning your head and trigger those nerves to tell your brain where your head is and how fast its moving - This in turn, immediately inhibits the R side, so the fluid is different on that R ear Same thing happens if turn head to the right side, your right side is excited and your left is inhibited - And tells brain where your head is positioned

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes biomechanics perspective

- Biomechanics perspective: anterior tilted scapula, over-activation of pec minor, inhibition of subscapularis (internal rotator of humeral head), and further straining of the anterior capsule Path of least resistance- she took the path of least resistance when her shoulder wouldn't move the way it normally does- she shifted her whole girdle forward which allowed her to reach behind her back Can elevate pure GH motion by stabilizing scapula - push on scapula and holding the coracoid process back and then holding the inferior angle of the scapula so she cannot do that compensatory movement **Now you can actually assess her ability to rotate the humeral head on the glenoid

Touch Response Interpretation matters: Our experiences contribute a little bit to this - Ex. If you read Braille a lot- will have a lot easier time with dexterity tasks b/c sensory receptors are already fired up - Brushing/tickling (defensive), increases or decreases your protective response??

- Brushing/tickling (defensive), increases protective response - Also anxiety - like people allergic to bees - may get really defensive when feel a light brush on their shoulder b/c think bee is there- a protective response - When in a fear state, will be on edge constantly, this might change how we interpret information coming in - Fight/flight information ***The way you function as a human DOES impact your sensory experience - As with much of human physiology, there's also an evolutionary influence - People are evolved from various other species and their environment - So we adapt all the time - this changes our sensory system - And has potentially WEAKENED IT!! Just depending on your job and unique experience in life- now we don't hunt and gather- so this changes how our body works

Cells - Come and go

- Cells die off and then come back - Cells regenerate from the bottom up (like in the skin) - The skin has a layer deep down that generates new cells - The new cells come up to the surface and pushes out old cells - Cells do need blood flow to survive - As cells get pushed up to the surface they receive less blood flow- basically die off as they lose the blood flow

The Skull Cranium • The skull is comprised of 22 bones - Connected primarily by fibrous, suture-type joints

- Connected primarily by fibrous, suture-type joints (don't move- but TMJ is an exception to that) - The temporomandibular joint (TMJ), a synovial joint, connects the mandible (jaw) to the skull

Which signal works the fastest? - A) Pain from getting a sliver - B) Muscle tendon reflexes like a knee jerk - C) Tapping like a kid trying to get your attention - D) Hair follicles sending a cold breeze

- D) Hair follicles sending a cold breeze

homunculus for the primary motor cortex

- Ex. Foot, hip and leg are pretty proportional - The hand requires a lot more mental energy to perform the dexterity tasks - Has a lot more space in the map - Face is an area we are very protective of- important for many social interactions, feeding ourselves - Tongue and larynx have a huge motor map for the need to feed ourselves and the importance of that motor function and the amount of time we spend each day on that activity

How forces activate sensory receptors 2 different muscle parts important here:

- Extrafusal muscle fiber - motor fiber - Intrafusal muscle fiber- have sensory fibers wrapped around them The blue and the purple on the picture - Primary and secondary sensory endings

- Muscle also has the Golgi Tendon Organ GTO in it which provides information during activities about the length and tension on that tendon

- GTO acts together with sensory receptors and intrafusal fibers to maintain or change the contraction during activities

Case Study Take-Aways - Neuromuscular dysfunction should not be overlooked in people with orthopedic injuries - Various ways to manage using simple and more complex/novel strategies - Generally, treatment is aimed at???

- Generally, treatment is aimed at increasing sensory feedback, and skilled training with repetition and cognitive effort to alter motor patterns in the motor cortex **need to have person pay attention to what they are doing in order to alter the motor patterns in the motor cortex - So creating a new motor map

Conclusion Sensory information facilitates interaction with the environment

- Helps us maintain balance - Reach for objects with or without looking - Play sports or instruments - Perform gross and fine motor activities

Kinesthesia

- Intrafusal fibers also provide information about the rate of length changes (velocity) and the amount of contraction or stretch in the muscle - Brain receives and interprets the info to understand the body's movement in space (Kinesthesia) Intrafusal muscle fibers detect the sensation of your head nodding off to sleep - Intrafusal muscle fibers detect changes in the anterior aspect of the neck so its forcing him to react- sort of this reflex as they are stretched - He is getting this sensory input, but his brain isn't interpreting it all of the way or seeing it as enough of a threat to wake up

Proprioception - Intrafusal OR extrafusal fibers provide information about the the length of the fiber?? - Brain receives and interprets this information to understand the body's position (proprioception)

- Intrafusal fibers provide information about the the length of the fiber - Brain receives and interprets this information to understand the body's position (proprioception)

Free nerve endings ****Protective

- Respond to damage or potential damage - Because of that, must be rapidly adapting (send signal quickly to pull hand away if touch something hot or sharp and you feel that pain)! -Thermoreceptors- detect heat and cold -Nociceptors - detect pain signals -Tickle, itch - also have tickle/itch response **Pruritis disorders- disorders of itching Itching is also a sign of healing - you know that pain signals are one of the first to come back after a nerve injury, so assuming that nerve is healing- the pain signals are going to come back first, temperature, AND itching - Itching is a good thing! There is an itch/scratch cycle - itching is relieved by this temporary pain signal coming from this scratch - serotonin is released from your brain which can cause more itching - Free nerve endings are surrounded by a Schwann cell Schwann cells help with myelination and regeneration capacity - But the free nerve endings themselves serve a protective nature ***Free nerve endings are also the first nerve to come back after an injury!!! - Makes sense from an evolutionary standpoint and functional standpoint - Pain signals come back first AND they are the LAST to be lost in a nerve injury And the first to come back

Ruffini Corpuscles - Slowly adapting fibers providing important information about stretching of skin across joints Detect shearing, friction and stretching of skin across joints - Particularly useful in the hand since there are less intrafusal muscle fibers Why? Hint: Extrinsic vs. Intrinsic muscle contributions

- Ruffini corpuscles in the hand are particularly useful b/c our hand has less intrafusal muscle fibers - Your hand does not have a lot of muscle in it compared to different parts of body - So if relying on intrafusal muscle fibers from the muscle belly to give info about proprioception, the hand is at a disadvantage here- and its important to know where hand is in space b/c use it so often - So Ruffini corpuscles are very important in hand You can do this for yourself - Spread fingers wide and feel the skin stretching on the palm- this is because of Ruffini corpuscles being intact- tells you that your hand is wide open and stretched Your skin is a lot thinner on the back of your hand - So when you make a fist can't really feel as much stretch on the back of your hand - UNLESS say you have a scar- simulate this by pinching skin on the back of your hand- now try and make a fist - When you do this, there is some extra PULL that happens- when people have scar tissue- they feel an extra pull- so stretch receptors are going to react a little bit more

Kinesiotape can be used to correct body dyskinesias by increasing awareness and improving neuromuscular control --can use this with TMJ_-

- Says you put an area of body on stretch, then there's a certain amount of tape stretch you also apply - In this case, it's very light tension so 0-15% of available tension in the tape to the upper part of the jaw and the lower part of the jaw So that can relieve some of the discomfort associated with TMJ - Especially if muscles around the joint are also becoming inflamed and not working properly

Case Study From a neuromuscular standpoint: So this is becoming her normal moment pattern, the more often she participates in this bad habit, the more likely her brain will adapt to this and decide this is the way movement is supposed to feel

- She's already got the new motor pattern since this is the way she has been doing it for the past three years as her shoulder got tighter and tighter ***It's about getting used to a new movement pattern and increasing the sensory input to support the new movement pattern we are trying to recommend

Sensing Position, Movement and Forces How engrained are motor patterns?

- Shows how complicated our neuromuscular system is!! - When you know how something is supposed to be done but can't achieve the motor pattern to respond to it - kind of like knowing what you are supposed to do in order to get up on water skiis or learning any motor skill You can know what is supposed to be done, but the motor pattern isn't there yet - So you don't have the map in your brain about how you're supposed to execute this action - Some things that can help to achieve that or build that motor pattern is NEUROMUSCULAR RE-EDUCATION - Talk about how to increase sensory signals to apply to this situation and others

Conclusion Sensory information received through a complex interplay of systems:

- Skin's receptors - Hair follicles - Muscle spindles - Joint sensory receptors - Vision - Vestibular sensory receptors

Touch Response Interpretation matters: Our experiences contribute a little bit to this - Ex. If you read Braille a lot- will have a lot easier time with dexterity tasks b/c sensory receptors are already fired up - Slow, steady gliding touch (calming), increases or decreases discrimination?

- Slow, steady gliding touch (calming), increases discrimination - When in a calm state like getting a massage - No threat - helps to calm down your system increases your discrimination then- ability to discriminate b/w sensation is actually increased with calming touch - May be easier for you to take control of a situation ***The way you function as a human DOES impact your sensory experience - As with much of human physiology, there's also an evolutionary influence - People are evolved from various other species and their environment - So we adapt all the time - this changes our sensory system

How forces activate sensory receptors These sensory receptors are set to do exactly ONE Job!!!

- So Ruffini endings are specifically for pressure Pacinian are also for pressure - Meissner corpuscles are for touch - Also have other nerve endings - Merkel cells are very important for touch - Also get into free nerve endings

The purpose of this alpha gamma co-activation is this is the lower motor neurons that are affected in this same process - So if only the alpha motor neurons were activated, then only extrafusal muscles contract---what is the significance of this?

- So if only the alpha motor neurons were activated, then only extrafusal muscles contract - The muscle spindle becomes slack and no action potentials are fired - So it is unable to detect further length changes ***SO basically if your gamma motor neurons are not firing, then your brain cannot detect the tension in the muscle - Alpha gamma co-activation occurs both intrafusal and extrafusal muscle fibers are contracting, and the tension is maintained in the muscle spindle AND it can still detect changes in the length ***So basically you need both of these nerves to be functioning!! (alpha and gamma)

Vestibular labyrinth - static vs. dynamic labyrinth

- Static labyrinth - Activated by normal gravitational forces (more with the ear sand) - Dynamic labyrinth- activated by rotary forces- When you twist your head (more with the semicircular canals)

Kinesthetic Awareness - Things that can help with your kinesthetic awareness Positive impact - Weight bearing - Resistance training Gyro exerciser - Vision - Repetition **Basis for many neuromuscular re-education concepts

- Weight bearing - Resistance training Gyro exerciser - Vision - Repetition **Basis for many neuromuscular re-education concepts Joint receptors in UE- (Ex. have less proprioception and kinesthetic awareness in LUE) - If you want to improve one's kinesthetic awareness - Have person go into quadruped and keep them in a weight-bearing position while you have them reach with their less affected side - This will have a positive impact on their left arm b/c the joint receptors are going to be more stimulated through that weight-bearing position - So resistance training is another example - good for kinesthetic awareness b/c it stimulates muscle fibers and receptors in the muscle belly - helps improve that signal - Using vision to compensate - AND repetition- the more you do something, the more set the motor pattern is **Basis for many neuromuscular re-education concepts - So when we really want to train someone to do something new or improve their motor patterns, may want to go through some neuromuscular re-education to actually help that person develop a habit of good posture (ex. Contracting their abs for example when they are lifting)

Skin - Largest sensory organ in the body

- Why we have to take good care of it - Skin is complex- if end up with a wound, if it doesn't heal could lead to infection or other disorders- may give less sensory signals - Even just having dry skin affects sensory receptors - Has a wide variety of sensory receptors - 4 layers make up epidermis - Sweat glands - Hair - Dermis below epidermis- where start to get blood flow into this- needed to keep receptors and tissues viable and to help healing - Hypodermis contains mostly adipose tissue just below the dermis

Sensory fiber in the skin- Meissners corpuscle (mechanoreceptor) - turns reception in skin into electrical signal- along afferent (ascending) tract

- arrives at DRG in SC to brain - motor signals come from anterior horn cell to motor fiber which tells your muscle to move

- Muscle spindles: intrafusal fibers provide information about the speed or rate of change and the length of muscle fibers whereas extrafusal fibers are more about?

- extrafusal fibers provide information about the muscle contraction force - Muscle also has the Golgi Tendon Organ GTO in it which provides information during activities about the length and tension on that tendon - GTO acts together with sensory receptors and intrafusal fibers to maintain or change the contraction during activities

Sensory conflicts- Your vision also kind of tricks you

- in the sense that when you are sitting at a stop light you have your foot on the break, you can feel the input from the pressure on your foot - but another car around you starts shifting, that gives your visual information that as though you are moving which may also make you feel disoriented for a second

Pacinian Corpuscles

- onset and removal of pressure - tapping or vibration - rapidly adapting These are way down deeper in the skin - they respond to pressure - makes sense that they are deeper they respond to pressure - they also respond to onset and removal of pressure like in tapping or vibration - they respond pretty quickly Think of this sort of like an air mattress - you push on it and it adjusts - the shifting is what gets the receptor fired up and send signal to the brain so you know what's going on

Ruffini corpuscles

- respond to continuous pressure - slowly adapting - particularly sensitive to drag and shearing stress wearing gloves skin stretch ***(important for proprioception!)** They are middle of the road here in terms of layers of the skin Particularly sensitive to drag and shearing stress - like rubbing your fingers together - will sense when rubbing hands together when you're cold- Ruffini corpuscles will detect which way you are rubbing your hands - this shearing/friction stress respond to continuous pressure as well - like wearing gloves - constantly fired up - sense this pressure ****very important- Ruffini corpuscles detect skin STRETCH!! - Very important for proprioception especially in your hand

Afferent: Arriving in the CNS

- sensory info - AND info from muscle spindles (intrafusal fibers)

Knee Jerk Reflex steps

1) Mallet hits patellar tendon- this excites nerve endings in the muscle spindle like the Golgi tendon organ in the quadriceps muscle 2) This sends a stretch signal to spinal cord via afferent nerve fiber and posterior root 3) Then once in the spinal cord, the afferent nerve ending excites the motor neuron int he spinal cord 4) the efferent signal in the motor nerve fiber stimulates the quadriceps to contract, producing knee jerk (this is kind of the feedback loop she talked about earlier) 5) at the same time, a branch of the afferent nerve fiber stimulates inhibitory motor neuron in spinal cord 6) That neuron inhibits motor neuron that supplies hamstring muscles- this is the nerve to the hamstring muscle 7) Hamstring contraction is inhibited so hamstrings (knee flexors) do not antagonize quadriceps (knee extensor) - so basically if you excite the quadriceps with this reflex hammer, you will get an inhibition of the hamstrings- so they don't antagonize or fight the quadriceps

Knee jerk reflex - inhibition portion 4) the efferent signal in the motor nerve fiber stimulates the quadriceps to contract, producing knee jerk (this is kind of the feedback loop she talked about earlier) 5) at the same time, a branch of the afferent nerve fiber stimulates inhibitory motor neuron in spinal cord

1) That neuron inhibits motor neuron that supplies hamstring muscles- this is the nerve to the hamstring muscle 2) Hamstring contraction is inhibited so hamstrings (knee flexors) do not antagonize quadriceps (knee extensor) - so basically if you excite the quadriceps with this reflex hammer, you will get an inhibition of the hamstrings- so they don't antagonize or fight the quadriceps

sensory homunculus

Demonstrates that the area of the cortex dedicated to the sensations of various body parts is proportional to how sensitive that part of the body is. - - Has a similar concept that the larger the body part, the more sensitive it is

Axial Skeleton The skeleton - Axial skeleton is comprised of?

Axial skeleton - Cranium (skull) - Vertebral column (spine) - Ribs - Sternum

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes Exercise approach:

Exercise approach: prolonged stretching of posterior capsule (sleeper or cross body stretch), scapular and rotator cuff strengthening - Stretch out muscles that have been overused - And stretch out posterior capsule which will allow correct movement

Muscles are made up of muscle fibers - Muscle fibers can also be called muscle spindles

Extrafusal muscle fibers- create the contraction that's where all of your actin/myosin binding happens Intrafusal muscle fibers- ones that are wrapped in sensory organ and give information to the brain about the amount of stretch and signal in the muscle

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes Let's think about this FIRST THING TO DO:

FIRST THING TO DO: STOP THE POOR HABIT!! Second thing to do: increase posterior capsule mobility - Only want her to go as far as she can without compensating - Need to help by increasing the glide, the movement of the humerus on the glenoid by stretching out shoulder capsule - will allow her to get better and better at reaching behind her back without compensating

Nerve endings that shed their protective sheaths, myelin and Schwann cells to permit the naked axons access to tissues on the borders of the dermis and epidermis Free nerve endings Cellular matrix Cerebrospinal fluid Neurotmesis

Free nerve endings

Goes to show there's a reason that gait and other activities and postures affect not only our spine and back, but the position of WHAT ELSE can also play a big role in the stability of your upper extremity too??

Goes to show there's a reason that gait and other activities and postures affect not only our spine and back, but the position of your pelvis can also play a big role in the stability of your upper extremity too

What structure detect the sensation of your head nodding off to sleep??

Intrafusal muscle fibers detect the sensation of your head nodding off to sleep - Intrafusal muscle fibers detect changes in the anterior aspect of the neck so its forcing him to react- sort of this reflex as they are stretched - He is getting this sensory input, but his brain isn't interpreting it all of the way or seeing it as enough of a threat to wake up - Brain receives and interprets the info to understand the body's movement in space (Kinesthesia)

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes Neuromuscular approach:

Isometrics focusing on activating subscapularis and inhibiting pec minor, resistance while again avoiding pec minor or other compensatory techniques (tactile and verbal cues), rhythmic stabilization through various arcs of motion, followed by using the new range of motion with a functional retraining task (passing the baton), next slide - Isometrics allow subscap to do the work and avoid pec minor from pulling forward - These help to rebalance the shoulder - Practice the new motion with functional retraining

Quick Poll • What's the one muscle that connects the upper extremities to the lower extremities?

Latissimus Dorsi!! - It connects your upper part of your humerus - It wraps around from anterior through under your armpit and goes posterior to the pelvis

Provide information about intermittent touch to the skin surface

Meissner's corpuscles

So when doing a sensory test on someone who has nerve injury, there are standards in terms of how long you give a patient to respond - you press down on the skin for 1.5 seconds, you lift the skin for 1.5 seconds - this gives this signal time to be interpreted by the brain and then have the person respond - you do also have the influence of your attention so when someone is getting a sensation test, they may need a little extra cue of like look pay attention - a sensory test is supposed to be random but expectations play a brain game (ex. If you expect thumb but actually pinky is involved) Which cell type is important for pressure and light touch which helps with dexterity??

Merkel Cells - Pressure and light touch- helps with dexterity - Close to the skin - Slowly adapting

Which type of cell is close to the surface of the skin- so one of the first after the hair follicles to sense TOUCH??

Merkel cells - VERY IMPORTANT - Pressure and light touch- helps with dexterity - Close to the skin - Slowly adapting particularly affected in diabetic neuropathy

Muscle stretch is detected with the intrafusal muscle fibers AND what else?

Muscle stretch is detected with the intrafusal muscle fibers AND the rate at which the muscle is stretched or changed - In stretched muscle you can see that AP are generated at a constant rate in that sensory fiber - So if this is one second, then the AP of the unstretched muscle is EVEN - a resting membrane potential - As you stretch that muscle in that same amount of time, stretching activates the muscle spindle which increases the rate of the AP - So now as the muscle is stretching, there is this detection that is happening in a rapid way - So that signal is getting up to your brain that the muscle is stretching at this certain rate over time The purpose of this alpha gamma co-activation is this is the lower motor neurons that are affected in this same process - So if only the alpha motor neurons were activated, then only extrafusal muscles contract - The muscle spindle becomes slack and no action potentials are fired - So it is unable to detect further length changes ***SO basically if your gamma motor neurons are not firing, then your brain cannot detect the tension in the muscle - Alpha gamma co-activation occurs both intrafusal and extrafusal muscle fibers are contracting, and the tension is maintained in the muscle spindle AND it can still detect changes in the length ***So basically you need both of these nerves to be functioning!! (alpha and gamma)

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes neuromuscular perspective

Neuromuscular perspective: altered input to motor cortex and resultant plastic reorganization - It doesn't FEEL right to move the way we're asking - Similar phenomenon happens with posture re-training as in correcting forward head From a neuromuscular standpoint: So this is becoming her normal moment pattern, the more often she participates in this bad habit, the more likely her brain will adapt to this and decide this is the way movement is supposed to feel - She's already got the new motor pattern since this is the way she has been doing it for the past three years as her shoulder got tighter and tighter ***It's about getting used to a new movement pattern and increasing the sensory input to support the new movement pattern we are trying to recommend

Neurons - Gets signals from cells

Neurons- Gets signals from cells - You have cells designated to receive specific information (Ex. Info about deep pressure or light touch) and you can't really turn them off unless you have a pathology or dysfunction or unconscious - brain is not receiving and interpreting info like when you are sleeping - But the cells themselves are never really turned off until they die and new ones are generated - Neurotransmitter turns the chemical signal into an electrical one - Ex. If a feather touches your hand or a spider crawls on your hand, you can't turn off the light touch cell that detects that sensory info - it then sends that signal to that neuron, then NT turns chemical signal to an electrical one which causes an AP to occur Cellular receptors and the processes associated with that= very cool

Case Study - Patient with posterior GH capsule tightness affecting her ability to reach behind her back - She has developed an abnormal movement pattern when putting on clothes OT Approach

OT bonus: incorporate other meaningful activities - Ex. If working on internal rotation behind their back, may want to have person string their belt loop behind their back and use good mechanics of the shoulder every single time - Could also use a string - And keep doing this repetitively - Need to stop the person if they are compensating or doing a poor movement pattern b/c don't want to give the brain any of that bad input- want to give it good input to secure this new movement pattern

Which sensory receptor cell is sort of like an air mattress? you push on it and it adjusts - the shifting is what gets the receptor fired up and send signal to the brain so you know what's going on

Pacinian Corpuscles - onset and removal of pressure - tapping or vibration - rapidly adapting

Respond more readily to tapping

Pacinian corpuscles

Hair Follicles - Activate when hair is bent - Rapidly adapting

Palisade and circumferential nerve endings on the surface of the outer root sheath of a hair follicle Hair follicles rapidly adapt - They will sense a light breeze, wind, and as hair follicles move they send that signal way down deep to the skin and to these palisade fibers Hair follicles are sensory signals - They send info into the skin and then send that electrical signal to the brain to let you know what is happening

Static Labyrinth - Head orientation: Vestibular/Visual/Neck stretch sensory

Picture of ear sand and other structures in static labyrinth give your brain info about where your head is in space

Sensing Touch through Skin Receptors The larger receptive fields of WHAT TWO SENSORY RECEPTORS provide generalized location information important for awareness of hand and foot placement when grasping, standing, or walking

Ruffini and Pacinian corpuscles provide generalized location information important for awareness of hand and foot placement when grasping, standing, or walking

Which sensory receptor cell is particularly sensitive to drag and shearing stress

Ruffini corpuscles respond to continuous pressure as well - like wearing gloves - constantly fired up - sense this pressure - like rubbing your fingers together - will sense when rubbing hands together when you're cold- Ruffini corpuscles will detect which way you are rubbing your hands - this shearing/friction stress Ruffini corpuscles detect skin STRETCH!! - Very important for proprioception especially in your hand

Nerve endings that are particularly sensitive to drag (shear stresses)

Ruffini nerve endings

Vestibular labyrinth Static Labyrinth

Saccular and utricular maculae - "Maculae have hair cells that become excited by shear forces acting on otoconia (ear sand). Striola separates the hair cells into two groups, so that when one side gets excited, the other side gets inhibited" Again, these are RECEPTORS- so they are responsible for sensing changes in the hair cells and the ear sand - So kind of the weight of that ear sand triggers the sensory signal to go to the brain to tell you what is happening Sacculae: movement in the sagittal plane (up and down)- so if jamming to a song- will be firing more and giving you info that you are bobbing your head Utricals: motion of the head in the coronal plane (lateral tilting) -like if you're going to stretch your upper trap

- Free nerve endings are surrounded by a Schwann cell

Schwann cells help with myelination and regeneration capacity - But the free nerve endings themselves serve a protective nature ***Free nerve endings are also the first nerve to come back after an injury!!! - Makes sense from an evolutionary standpoint and functional standpoint - Pain signals come back first AND they are the LAST to be lost in a nerve injury And the first to come back

Vestibular labyrinth Dynamic Labyrinth

Semicircular canals- most important thing in terms of where your head is during rotary motion - Posterior/anterior/horizontal - Angular and rotary movement "The cristae in the ampulla of the ducts sense discrete movements in various planes of movement" "Displacement of the fluid in the ampulla in one direction fires the hair cells rapidly and decrease their rate of firing when moving in the opposite direction"

Sensory Conflicts- spinning in a chair

Sensory conflicts are what actually cause motion sickness - If you are sitting in a chair and you start spinning, the information from your body - the pressure on your butt for example, from your arms holding on in one spot- all feel is if it is static in one position - So you are getting info from your brain that you are sitting still - But your vestibular sensory organs are telling your brain you are moving - So you get a lot of different info - kind of a conflict of information - May increase your nausea and sickness as your brain experiences conflicting information

Sensory Conflicts-when on a boat

Similar to what you may be experiencing on a boat and you get motion sickness that way - When you look at the deck of the boat- it tells your brain you are not moving but when you look at the land and water around you, the visual info to your brain tells you that you are moving - So again, the complex problems make you sick

Sensing Touch Pay attention mostly to picture on the right (smooth skin) - also called glabrous skin Picture on the left- hairy skin - Same kind of set up except the hair also incorporates another receptor- serves as a receptor on its own - Three morphologic types of sensory nerve ending in hairy skin

So when we are talking about the innervation of glabrous (smooth) skin - Talk a lot about the cells mixed in throughout the image

Let's say I want to kick my leg straight, my brain has learned throughout my life that when I kick, that I feel maybe a slight stretch in my hamstrings and I feel a tightening or shortening of the muscle fibers in my quads - That information over time becomes more and more secure map that continues to become better over time - The more motor patterns you do, the more your brain has to interpret

So your brain learned what it feels like to kick - you can close your eyes and look at it and you can generally feel what position your knee is in space and probably be pretty good at estimating the joint degree of motion just b/c of your experience - And you know what it feels like So intrafusal fibers are very important to proprioception- to understanding where your body is in space

Vestibular Apparatus

What is responsible for assessing your head position, spatial orientation, body movement and position Vestibular labyrinth - Static labyrinth (Activated by normal gravitational forces) - Dynamic labyrinth (activated by rotary forces)

Homunculi

models that show the relative space that neurons related to different parts of the body occupy in the sensory cortex and motor cortex of the cerebral hemispheres. - in the cerebrum - the larger the body part is represented on this map, the more focus or the attention it has in the cortex

- In stretched muscle you can see that AP are generated at a constant rate in that sensory fiber - So if this is one second, then the AP of the unstretched muscle is EVEN - a resting membrane potential - As you stretch that muscle in that same amount of time, stretching activates the muscle spindle which does WHAT to the AP???

stretching activates the muscle spindle which increases the rate of the AP - So now as the muscle is stretching, there is this detection that is happening in a rapid way - So that signal is getting up to your brain that the muscle is stretching at this certain rate over time The purpose of this alpha gamma co-activation is this is the lower motor neurons that are affected in this same process - So if only the alpha motor neurons were activated, then only extrafusal muscles contract - The muscle spindle becomes slack and no action potentials are fired - So it is unable to detect further length changes ***SO basically if your gamma motor neurons are not firing, then your brain cannot detect the tension in the muscle - Alpha gamma co-activation occurs both intrafusal and extrafusal muscle fibers are contracting, and the tension is maintained in the muscle spindle AND it can still detect changes in the length ***So basically you need both of these nerves to be functioning!! (alpha and gamma)