Kin Shoulder Joint
Horizontal adduction (flexion)
A horizontal movement of the humerus across the chest in a transverse plane
Shoulder extension
A return from flexion in the sagittal plane
Extrinsic
Arise and originate outside a specific body part
?
Clavicular vs sternal portion of pectoralis major
infraspinatus and tere minor -lighter resistance with higher reps or the use of elastic resistance (tubing, theraband) or light weights are both effective
Direct movements of external rotation against resistance are effective in strengthening the ___ and ___. What kind of work out is most effective for strengthening these little muscles?
contraction of the Lat dorsi contracts and creates a string counterforce to depress the scapula
During elevation due to the origin being fixed of the shoulder, what happens?
intrinsic
Entirely contained within a specified body part
shoulder flexion
Forward movement of the humerus in the sagittal plane
through resistance exercises in the direct plane of internal rotation movement( arm wrestling) - also effectively strengthened with movements involving the Lat dorsi and teres major Also the external rotators should be strengthened specifically, due to strength imbalance of the two movements
How can the subscapularis be strengthened ?
Lat dorsi
Largest muscle in the upper body
shoulder abduction
Lateral movement of the humerus occurring in the frontal plane
Humeral extension
Lats Dorsi is the most powerful muscle involves in ___
Anterior deltoid
Most compound movements involving the clavicular portion of the pectoralis major also involve ____.
hyperextension
Movement in extension beyond the anatomical position
Teres major o- Posteriorly on the inferior 3rd of the lateral border of the scapula I- the medial lip of the bicipital groove of the humerus A- extension, internal (medial rotation) and adduction of the humerus
O I A
Anterior deltoid O-anterior lateral 3rd of the clavicle I- deltoid tuberosity on the lateral humerus A- Flexion, horizontal adduction of humerus , internal rotation, and abduction of the humerus ( a few fibers)
O? I? A?
Coracobrachialis o- coracoid process of the scapula I- the middle 3rd of the medial border of the humeral shaft A. - flexion, adduction, and horizontal adduction of the humerus - a weak muscle and the smallest of the humeral region shares a common origin attachment as the short head of the biceps brachii
O? I? A?
infraspinatus O- infraspinatus fossa of the spacular I- greater tubercle of the humerus a- External rotation, horizontal abduction, and extension of the humerus - helps stabilize the humeral head in the glenoid fossa
O? I? A?
Latissimus Dorsi -Orgin- posterior crest of the illium, back of the sacrum, spinous process of lumbar and t7-t12 vertibrae and slips from the lower 6 ribs -I- The bicipital groove of the humerus A- Extension, internal(medial) rotation, adduction, horizontal abduction of the humerus -----Most specifically in a path of adduction that passes posterior to the trunk - lat pulldowns
O? I? A?ex
Subscalpularis o- Subscapular fossa of the scapula i- lesser tubercle of the humerus A- internal(medial) rotation, adduction, and extension of the humerus -depressed the humeral head to keep it in the glenoid fossa - some involvment in horizontal adduction
O? I? a?
Pectoralis major o- 1. clavicular head- medial 1/2 of the anterior surface of the clavicle 2. sternal head- sternum and the cartilage of the upper 6 ribs I-lateral lip of the bicipital grove of the humerus A- horizontal adduction, internal rotation, adduction, flexion of the humerus - most specifically during adduction movements that pass anterior to the trunk??
O? i? A?
Supraspinatus O-medial 2/3 pf the supraspinatus fossa I- superiorly on the greater tubercle of the humerus A- Abduction of the humerus and stabilization of the humeral head in the glenoid fossa
O? i? a?
repeated overhead motions or forceful pulling motions ex. repetitive throwing motions
Rotator cuff injury is commonly associated with motions that require?
intrinsic, glenohumeral joint
Shoulder joints with an origin attachment on the scapula and clavicle and an insertion on the humerus are regarded as ____ to the _____
Subscapularis , biceps brachii tendon (long head)
Tears to the ___ are less common but are more problematic bc they often involve injury to the _____
1. Abduction - results from the medial deltoid and supraspinatus contraction, which also results in a slight depression of the humeral head 2. adduction - results from the contraction of latissimus Dorsi, teres major, pectoralis major (sternal portion), and posterior deltoid (lower fibers) - teres major adducts posterior to the midline of the body ( arm moving behind the back)
Tell about the shoulder movements in the frontal plane?(2)
1. external rotation- results from a contraction of the infraspinatus and teres minor. - the posterior deltoid is only involved if the humerus is being horizontally abducted or extended while externally rotated 2. internal rotation- results from contraction of the subscalpularis, teres major, latissimus dorsi, anterior deltoid, and the clavicular portion of the pec major.-there is also minimal involvement of the coracobrachialis and the short head of the biceps brachi during internal rotation 3. horizontal adduction - results from contraction of the pectoralis major, anterior deltoid, and some minimal involvement of the short head of the biceps brachii 4. horizontal abduct- results from contraction of posterior deltoid, posterior portion of the medial deltoid, weak assistance of the infrspinatus and teres minor and long head of tricep brachii
Tell me about the shoulder movements in the horizontal plane
flex and adduct, horizontally adduct, ex. bench press, push ups, and dumbell flies
The Coracorbrachialis is aligned to ___ and ___ the humerus, but can be best strengthened in actions that ____ the humerus against resistance examples
1/4th 25%, the labrum 75%
The Glenoid fossa is ____ the size of the humeral head what increases the contact area of the humeral head by ___ %?
- push ups - dips - bench presses -dumbbell flies, cable crossovers -overhand motions such as baseball, javelin, tennis swings and etc
The Pectoralis major is directly involved with what activities?
Lat dorsi - suspended on parallel bars - walking with crutches - pushing down on the arm rails of a chair
The __ is a scapular depressor during activities that elevate the scapula due to origin being fixed. ex?
The brachial plexus ( group of spinal nerves composed of cervical nerves 5-8 and thoracic nerve 1)
The muscles of the shoulder joint are innervated by?
1.movements that are performed with the humerus moving in shoulder extension or in horizontal abduction 2. shoulder external rotation, most specifically when horizontal abduction and external rotation are occurring in a simultaneous movement 3. forceful adduction of the humerus from an overhead position (lat pull downs or rowing machine)
The posterior deltoid is highly active during :
scapula, humeral head
The rotator cuff muscles arise from the ___ and connect to the ____ to form a cuff
Extension, flexion
The shoulder joint is most stable during _____ but vulnerable to injury or dislocation during_____.
anterior dislocation, arm tackle
The stabilizing action of the subscapularis prevents ___ during force lateral rotation of the humerus in an abducted position (ex)
Infraspinatus, teres minor, and subscapularis
What 3 muscles depresses the humeral head during flexion and abduction and prevent it from jamming against the acromion process?
? latissimus dorsi, teres major, posterior deltoid, the sternal portion of the pectoralis major
What 4 muscle attribute to internal rotation of the humerus?
it elevates and rotates up
What happens to the scapula doing shoulder flexion?
O-Inferior edge of the spine of the scapula I- deltoid tuberosity on the lateral humerus A- Prime mover of :Extension, horizontal abduction, and external rotation - and not (abduction of the humerus
What is the Origin, insertion, and action of the posterior deltoid? ex of exercises?
Muscles, ligaments, and to some extent by the glenoid labrum
What is the shoulder joint stabilized by?
Stabilizing action and internal medial rotation
What is the subscapularis prime movers of?
The lats dorsi and teres major
What muscles form the posterior axillary fold?
- it is strongly involved in popular movements that emphasize shoulder internal rotation ( bench press, push ups) - the shoulder internal rotators create a stronger force than the shoulder external rotators - it is involved with many of the more popular sport and fitness movements
Why are muscle imbalances of the pectoralis major so common?
It is less stable than other joints because of it's excessive mobility
Why is the shoulder joint most susceptible to injury?
Shoulder(glenohumeral) joint Head of the humerus and the glenoid fossa
____ is a multiaxial, ball and socket joint that articulates what surfaces?
Glenoid labrum
a fibrocartlidge rim encircling the glenoid fossa
Horizontal abduction ( extension)
a horizontal movement of the humerus away from the chest in a transverse plane
Shoulder adduction
a return motion in from abduction
Scaption
a shoulder flexion movement that occurs midway between frontal and sagittal plane
Rotator cuff SITS 1. Supraspinatus 2. Infraspinatus 3. teres minor 4 subscapularis
an anatomical term given to the group of muscles that their tendons that act to stabilize the glenohumeral joint What does it include and what is the accronym
Anteriorly, laterally, and posteriorly The unique fiber shape creates multiple movement patterns - each group of fibers overlap with adjacent fibers, which involves them to some extent with their adjacent group of deltoid fibers
fibers of the deltoid pass ___, ____, and _____ to the glenoid fossa and what does this create?
through the scapula and the scapula's attachment through the clavicle and sternoclavicular joint
how does the shoulder joint link to the axial skeleton?
external (outward, lateral) rotation
lateral rotation of the humerus away from the midline in the transverse plane
1. deltoid 2. coracobrachialis 3. teres major 4. Supraspinatus 5. infraspinatus 6. teres minor 7. sunscapularis
list the intrinsic muscles of the shoulder
internal (inward, medial) rotation
medial rotation of the humerus toward the midline in the transverse plane
Latissimus dorsi and pectoralis muscle
name the extrinsic muscles of the shoulder joint
teres minor O- upper 2/3 of the lateral boarder of the scapula I- greater tubercle of the humerus A- external(lateral) rotation, horizontal abduction, and extension of the humerus - basically has the same function as the infraspinatus and provide posterior stability to the shoulder joint
o? i? A?
Medial deltoid o- lateral aspect of the acromion process I- deltoid tuberosity on the lateral humerus Action. A- abduction of the humerus ex. Lateral raises or upright row Strongly activated in all humeral abduction movements a few fibers assist in horizontal abduction
o? i? a? ex?
internal rotation Heavy movements such as bench presses and lat pull downs involve internal rotation - strong emphasis should be applied to strengthing the movements of external rotation in order to maintain optimal shoulder health
of shoulder internal rotation and external rotation, which will always be stronger because of the muscles involved?
Anterior deltoid
only shoulder joint muscle that has a origin on the clavicle
anterior and medial deltoid
scaption involves combined action of ___ and ____
eccentric, infraspinatus and teres minor to internal rotation
shoulder internal rotation, such as throwing motions or high velocity tennis serves, place a strong ___ force on the __ and ___ to decelerate ___ rotation
extrinsic, glenohumeral joint
shoulder joint muscles with an origin attachment to the trunk and an insertion on the humerus are considered ____ to the ____
Trauma to the shoulder or wear and tear of tendons under the acromion
tears to the rotator cuff can result from:
1. Flexion - results from contraction of the Anterior Deltoid and the clavicular portion of the pectoralis major with some assistance from the coracobrachialis 2. Extension- results from contraction of the latissimus dorsi, teres major, posterior deltoid, the sternal portion of the pectoralis major, and the long head of the the triceps brachii
tell about shoulder movements in the sagittal plane?(2)
- movement in a plane of true horizontal adduction (90 degrees of shoulder abduction ) involves the PMJ as a whole - movement in a plane diagonal and upward plane of horizontal adduction, beginning with the shoulder in less than 90 degrees of abduction (optimal pos
the fibers of the pectoralis major are aligned to create 2 distinguished lines of pull. tell about it???? slides 37 - 38
the shoulder is in external rotation as opposed to internal rotation
the supraspinatus is a stronger abductor when?
coracobrachialis
weakest and smallest muscle of the humeral region
The infraspinatus and teres minor while the infra is larger and stronger than the TMinor
what are primary external external rotators of the shoulder joint?
- attempts to achieve abduction through scapular elevation - irregular abduction patterns when resistance is received
what are some indications of supraspinatus weakness?
It is the most moveable joint of the body and it can move in all 3 cardinal planes
what are some unique properties of the shoulder joint?
-overhead pressing movements - pushups - parallel bar dips -bench presses ( horizontal and incline) - dumbell front raises -Scaption movements
what are some ways to strengthen the anterior deltoid?
- dumbell lateral raises - upright rows -some overhead pressing movements if humerus moves in frontal plane -scaption movements
what are some ways to strengthen the medial deltoid?
- bent over dumbbell lateral raises -horizontal rowing motions -chin ups, pull ups, lat pull downs, - rope climbing -resisted shoulder external rotation movements
what are some ways to strengthen the posterior deltoid?
Supraspinatus infraspinatus teres minor subscapularis
what are the muscles of the rotator cuff?
Superior- 1. deltoid 2. Supraspinatus Anterior- 1. pectoralis major 2. coracobrachalis 3. subscapularis - biceps brachii and triceps brachii Posterior- 1. infraspinatus 2. teres minor 3. latissimus dorsi 4. teres major ( long head)
what are the muscles that are involved in shoulder joint movement? what region? ***?
It compresses the glenohumeral joint to allow the deltoid to complete shoulder elevation
what does the rotator cuff do during shoulder elevation?
The scapula adducts
what does the scapula do during shoulder horizontal abduction ?
in abducts
what does the scapula do during shoulder internal rotation?
the scapula abducts
what does the scapula do when shoulder is in horizontal adduction
-extension -chin ups, pull ups, pull downs, horizontal rowing movements, swimming, rope climbing, parallel bar dips (depression)
what exercises that require a strong ____ to effectively strengthen the Lat dorsi
It is separated from the teres minor by the long head of the triceps
what happens anatomically when the teres major passes to its insertion?
the scapula depresses and then rotates downward
what happens to the scapula doing during shoulder extension?
the scapula adducts
what happens to the scapula during external rotation of the shoulder joint?
the scapula rotates upward
what happens to the scapula during shoulder abduction?
rotates downward
what happens to the scapula during shoulder adduction
a significant strength decrease in internal rotation and also anterior instability of the glenohumeral joint
what happens when the subscapularis is weak?
Maintaining good strength and endurance in the external rotator muscles
what is glenohumeral stability dependent on?
Damage to the rotator cuff
what is one of the most common causes of shoulder pain?
maintain balanced strength and flexibility (agonist/antagonist relationship) between external and intenal muscle
what is the best preventative approach of rotator cuff injury?
The subscapularis 53%
what is the largest and strongest rotator cuff muscle? is accounts for ___% of the RC strength
The infraspinatus
what is the second most commonly injured muscle of the rotator cuff?
internal rotation - rhomboids must stabilize the scapula
what is the teres major a major contributor to? (motion) what must happen for this to occur?
"latissimus Dorsi's little helper"
what is the teres major often referred to as?
- strongest involvement is with Flexion (front raise) - secondary muscle for shoulder internal rotation -it works strongly with the Pectoralis major during horizontal adduction - a few fibers are active during shoulder abduction -is active in all pressing exercises, both vertical and horizontal, and other patterns of lifting overhead
what is unique about the anterior deltoid?
shoulder extension, adduction, and internal rotation - also carries shoulder joint movement through extension to a postion or hyper extension
what motions does the Lat dorsi contract powerfully during?
scaption
what movement is considered to be more functional for basic activities involving elevation of the arms overhead
a combination of humeral flexion, adbuction, extension, hyperextension, and adduction resulting in a cone shaped movement
what movements are used to complete humeral circumduction?
Teres major
what muscle assists all the actions of the latissimus dorsi?
the supraspinatus which are usually acute injuries from shoulder trauma and mild to moderate strains or tears resulted from repeated overhead movements such as throwing or overhand strokes or swimming
what muscle of the Rotator cuff is most often injured?
scapular movement
what provides the basis for shoulder (humeral) movement?
Medial deltoid and supraspinatus -The supraspinatus is more directly involved in the intital stage of the movement as it works hard to stabilize the head of the humerus - the medial deltoid does not have a strong angle of pull in the initial stage but is strongest from the mid portion of the range (30 to 90 degrees of abduction)
what two muscles work closely together during shoulder abduction ? explain
the humeral head would ride up partially out of the glenoid fossa and thus reducing the efficiency of the deltoid
what would happen if you didnt have a rotator cuff?
the supraspinatus could provide weak abduction through the range of shoulder abduction
what would happen in the total absence of the medial deltoid to abduction?
when the top of the humeral head slips out of the glenoid fossa
when does dislocation of the shoulder joint occur?
motions that occur between 60 and 150 degrees of the 180 degree arc of shoulder flexion
when does the scapula move in concert with the humerus?
because they stabilize the head of the humerus in the small and shallow glenoid fossa of the scapula
why is the rotator cuff so important?
