Human Anatomy Exam 3

Organization of the Brachial Plexus

5 Roots - C5,6,7,8 and T1 3 Trunks - Superior, Middle and Inferior 3 Anterior and 3 Posterior Divisions 3 Cords - Lateral, Posterior and Medial 17 Peripheral Nerve Branches : Too many to list here!!

Teres Minor

Origin: Superior part of Lateral Scapula Border Insertion: Inferior facet of Greater Tuberosity Action: External Rotation of Shoulder Nerve: Axillary [Works in conjunction with the other RC to compress the GC increasing joint congruity] (- Externally rotates shoulder - Axially nerve - Much weaker external rotator)

Forearm (Antebrachium)

part between the elbow and wrist contains the ulna and radius connects the elbow and wrist [Bones connected by the interosseus membrane] Wrist - True wrist joint: carpal bones and radius (ulna not directly articulated)

Extrinsic Dorsal and Palmar Ligaments

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The Wrist

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Hypothenar Component

Abductor digiti minimi Flexor digiti minimi Opponens digiti minimi [Median Nerve]

Arm (Brachium)

(- Allowed to call biceps) the part between the shoulder and elbow containing the humerus contains the humerus connects the shoulder to the elbow [Biceps occupies the anterior of the arm Triceps occupies the posterior of the arm] Elbow - True joint = hinge - Radius and humerus - Humerus has plane gliding joint - Pronation - palms down; RADIUS MOVING - Proximal - just spins on own axis - Distal in wrist complex - spins around ulna - Antebrachial

Upper Extremity Osteology

(- More mobility than stability; built for functions; - Ability for fine motor control - (when moving - muscles supply forces; when static- now static stabilizers are working) - Concentric contraction: flexing elbow - Eccentric movement: opposite; moving away from midpoint - Dynamic stabilizers (muscles) play bigger role in upper extremity o Rotator cuff muscles to keep humerus up o During abduction, rotator cuff muscles shorten - very ineffective o Scapular-humeral rhythm -> 1/3 of movement of shoulder (scapula rotation))

Neurology and Angiology of the Upper Extremity

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The Glenoid Labrum

A fibrocartilaginous ring attached to the margin of the glenoid cavity Serves primarily to deepen the glenohumeral joint Also widens the glenoid cavity and improves the congruity of the glenohumeral joint The peripheral surface of the labrum is attached to the joint capsule [Superior portion of the labrum blends with the biceps tendon]

Thenar Compartment

Abdcutor Pollicis Brevis Flexor Pollicis Brevis Opponens Pollicis NO O and I but actions

Arthrology continued

Annular Ligament - The Annular ligament is attached at its ends to the anterior and posterior margins of the radial notch of the ulna - 4/5 of a ring that encircles the radial head - Annular ligament keeps radial head in proximity of ulna [A distractive force of sig magnitude may actually cause the radial head to dislocate from the ligament...nursmaids elbow] Humeroulnar Joint - Saddle shaped joint - Uni-axial hinge joint that allows flexion & extension - Capsular pattern is flexion is limited more than extension - Resting position is 70º flexion and 10º supination - Closed pack position is full extension with supination [Extension limited by bony block Closed packed is the position where the joints have their most contact.] Humeroradial Joint - Capsular pattern is flexion is limited greater than extension - Resting position is full supination with elbow extended - Closed pack position is 90º of flexion and 5º of supination [Dr. James Cyriax was the first to extensively study soft tissue lesions. When inflammation of a joint is present (known as synovitis or capsulitis), not only does passive stretching of the capsule cause pain but a limitation of range of motion of the involved joint is always found to be in a specific pattern; this pattern is always similar for that particular joint, although each joint has a different and instantly recognizable capsular pattern.] Proximal Radio-Ulnar Joint - The superior radio-ulnar joint is the articulation between the radial notch on the ulna, the annular ligament and the cylinder shaped head of the radius - The axis of rotation extends from the radial head to the ulnar head [Surface of the radial notch is concave and covered by articular cartilidge Longitudinal axis] - Motions possible at this joint are pronation and supination - Capsular pattern is equal restriction of pronation & supination - Resting position is 70º flexion & 35º supination - Closed pack position is maximum pronation Restraint to Motion - Pronation - approximation of ulna to radius - Supination - interosseus membrane

Quadrangular Space

Borders - Teres Minor - Long Head of Triceps - Teres Major - Shaft of the Humerus Contents - Axillary Nerve - Posterior Humeral Circumflex Artery [Works in conjunction with the other RC to compress the GC increasing joint congruity]

Bones of the Upper Extremity

Clavicle Scapula Humerus Radius Ulna

Subacromial Space

Clinical Relevance: Primary impingement: - structural stenosis of subacromial space Secondary impingement: - functional stenosis of subacromial space due to abnormal arthrokinematics [Primary is the result of bone spurs ] Avoidance of impingement during elevation of arm requires: - external rotation of humerus to clear greater tuberosity - upward rotation of scapula to elevate lateral end of acromion

Supinator

Deep in the cubital fossa Forms the floor of the cubital fossa with the brachialis Has humeral and ulnar heads of attachment Deep branch of radial nerve passes between the two parts of the muscle Exits muscle as the posterior interosseous nerve O: lateral epicondyle of the humerus I: lateral, posterior and anterior surfaces of proximal third of the radius A: supinates forearm N: deep branch of radial nerve

Scapulohumeral Musculature

Deltoid Teres Major Rotator Cuff Muscles - Supraspinatus - Infraspinatus - Teres minor - Subscapularis

The Hand - Intrinsic Myology

Divided into Four Compartments - Thenar compartments - Adductor compartment - Hypothenar compartment - Central compartment

Biceps

Don't forget that the biceps is the most powerful supinator of the forearm

Coracobrachialis

Elongated muscle of the superomedial arm - Origin: Coracoid process - Insertion: Middle 1/3 of the medial humerus - Action: shoulder flexion, adduction - Nerve: Musculocutaneous nerve Lies under the short head of the Biceps [Note that the muscle is peirced by the musculocutaneous nerve on it's way to the biceps] (- Brachial plexus is deep to clavicle - Nerve pierces this and comes out before piercing the biceps (help for hint) - Shoulder flexion, adduction, possible internal rotation (when in full external rotation, but not while in neutral)) (Shoulder flexion: biceps, coracobrachialis Adduction: pec major, coracobrachialis Internal rotation: adductors Anterior muscles: flex, adduct, or internally rotate Protract scapula: pec minor, serratus anterior - Inferior attachment to ____ = depressor of scapula)

Wrist Extensors

Extensor Carpi Radialis Longus Extensor Carpi Radialis Brevis Extensor Carpi Ulnaris

Finger Extensors

Extensor Digitorum Extensor Digiti Minimi

Brachialis

Flattened fusiform muscle Lies posterior (deep) to the biceps Distal attachment covers the anterior part of the elbow joint O: distal half of anterior surface of the humerus I: coronoid process and ulnar tuberosity A: flexes forearm (main flexor of the forearm) N: musculocutaneous nerve

Flexors of the Wrist

Flexor Carpi Ulnaris Palmaris longus Flexor Carpi Radialis

Triceps

Large fusiform muscle in the posterior compartment of the arm 3 heads: long, lateral and medial O: long head: infraglenoid tubercle of scapula lateral head: posterior surface of the humerus superior to the radial groove; medial head: posterior surface of the humerus inferior to the radial groove I: proximal end of the olecranon of the ulna A: extends forearm N: radial nerve

Subclavius

Lies almost horizontally when the arm is in the anatomical position Affords some protection to the subclavian artery when the clavicle fractures Origin: junction of the first rib and its costal cartilage Insertion: inferior surface of the middle third of the clavicle Action: anchors and depresses the clavicle Nerve: nerve to subclavius [Nerve to the subclavius is off the superior trunk] [Don't forget its supraclavicular] (- 1st rib to subclavian groove - Stabilizes scapula during motion (lol because scapula is already stable) - Can depress clavicle when needed (will happen anyway in response to scapula-humeral motion) - Nerve to subclavius)

Extensor Carpi Ulnaris

Long fusiform muscle Located on the medial border of the forearm Has two heads O: lateral epicondyle of the humerus I: base of the 5th MC A: extends and adducts (ulnarly deviates) the wrist N: posterior interosseous nerve [The PIN is a continuation of the deep branch of the radial nerve.]

Flexor Carpi Radialis

Long, fusiform muscle located medial to the pronator teres Fleshy belly is replaced by a long, flattened tendon and becomes cord-like as it approaches the wrist O: medial epicondyle of the humerus (common flexor origin) I: base of the second MC A: flexes and abducts (radially deviates) the wrist I: median nerve

Central Compartment

Lumbricals Interossei (blend into extensor expansion;)

Latissimus Dorsi

Means "widest of the back" Large Fan shaped muscle [But look at the action a little bit closer and you'll find that there are other actions at work here What might an additional or reverse action be?? Look at the origins and you'll find that there is also support to the pelvis from the iliac crest attachment] Origin: Spinous processes of T6 through T12, iliac crest and thoracolumbar fascia Insertion: Floor of intertubercular groove Action: Extension, Adduction and Internal Rotation of shoulder Nerve: Thoracodorsal nerve (from Brachial Plexus) [From the posterior cord of the plexus Travels with the artery and the nerve then along the serratus anterior] (- Large: multiple areas where it attaches o Extends sacrum, iliac crest, and spinous processes - Attaches to floor of intertubercular sulcus/groove - Thoracolumbar fascia - lot of muscles that contribute to layers - Extends, adducts, and internally rotates shoulder (because attaches anteriorly) - If getting arrested - muscle to have hands behind back - Triangle of auscultation o Listen to breath sounds)

The Hand - Cutaneous Innervation

Median Nerve Ulnar nerve radial nerve

Bones of the Hand

Metacarpals Proximal Phalanges Middle Phalanges Distal Phalanges

Upward Scapular Rotation

Musculature involved - Upper Trapezius -- Elevation and Upward rotation Lower Trapezius - Depression and Upward rotation Serratus anterior - Protraction - Holds scapula to the thoracic cage

Flexion-Extension

Occurs about an axis that is perpendicular to the glenoid cavity As a result, flexion occurs in an anteriomedial direction and extension in a posterolateral direction

Abduction-Adduction

Occurs about an axis that lies parallel to the glenoid cavity Axis runs anteriomedially to posteriolaterally As a result, abduction-adduction occurs in a plane anterior to the frontal plane Abduction of the glenohumeral joint requires external rotation to allow the greater tuberosity to pass under the coracoacromial arch

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Pronation - Pronator teres - Pronator quadratus Supination - Supinator - Biceps Wrist extensors - ECRL - ECRB - ECU Wrist flexors - FCR - FCU - Palmaris longus

Superficial (flexors)

Pronator Teres Flexor Carpi Radialis Longus Palmaris Longus Flexor Carpi Ulnaris (common flexor origin) Flexor Digitorum Superficialis (more intermediate) [See elbow for origin and insertion]

Anconeus

Small and relatively unimportant Triangular shaped muscle on posteriolateral aspect of the elbow Usually blended in with the triceps [But is always easy to find and a great test question.] O: lateral epicondyle of the humerus I: lateral surface of the olecranon A: assists triceps in extending the elbow N: Radial

Bones of the Wrist

Scaphoid Lunate Triquetrum Pisiform Trapezium Trapezoid Capitate Hamate

The Carpals (all bones)

Scaphoid, Lunate, Triquetrium, Pisiform, Trapezium, Trapezoid, Capitate, Hamate [Distal Carpal Row Articulates with the Phalanges] (scaphoid and lunate form convex surface to form radial carpal joint - true wrist joint triangular fibrocartilaginous complex - stability in medial aspect; and between distal radialulnar joint)

Pronator Quadratus

Small muscle that is quadrangular shape Cannot be palpated Deepest muscle in the anterior aspect of the forearm O: distal fourth of the anterior surface of the ulna I: distal fourth of the anterior surface of the radius A: pronates forearm N: anterior interosseous nerve from the median nerve

The Elbow

The elbow is the intermediate joint of the upper extremity and allows us to position the terminal device of the upper extremity, the hand, into any position in space The extended and pronated forearm takes hold of food and the result of flexion and supination carries food to the mouth The "elbow" is the distal articulation of the humerus and the radius and the ulna, as well as the proximal articulation of the ulna with the radius

The Metacarpals

The metacarpals are miniature long bones Metacarpal bases articulate with distal row of carpal bones and are irregular in shape. The articulation of the metacarpal with its carpal partner as Carpometacarpal (CMC) joints Articulation of metacarpals with proximal phalanges are the metacarpal phalangeal joints (MCP joints) (- 1-5 medial to lateral (thumb is 1; pinky is 5) - Distal part = head; proximal = base)

Neurology

The nerve Supply to the Upper Extermity comes from the Brachial Plexus Brachial Plexus passes between the clavicle and the 1st rib on its way to the arm. This is a site for potential impingement (Thoracic Outlet Syndrome)

Roots of the Brachial Plexus

The plexus gets branches from the C5, C6, C7, C8 and T1 spinal nerves. The Ventral Rami of these nerves form the Brachial Plexus. May receive contribution from C4 and T2 as well. 5 roots combine to form 3 trunks.

Introduction

The upper extremity is specialized for grasping and manipulation The main function of the upper extremity is to position the terminal organ of the upper extremity, the hand, in space for prehension Designed for mobility at the expense of stability Each part of the upper extremity is characterized by an increased ability to fractionate movement (ie. the digits- fingers and thumb being the most mobile The upper limb can be divided into 4 segments The Pectoral Girdle The Arm The Forearm The Hand [Grasping and manipulation require a fixed proximal segment and a moving distal segment Usually not involved in weightbearing. Again, stability has been sacrificed at the expense of mobility. This is not necessarily an increase in the degrees of freedom, rather an increase in the ability of the fine motor control of the part in question The increase in fractionation and fine motor control is a direct result of the innervation and tht4e number of fibers that innervate each nerve.]

The Sesamoids

There are two sesamoid bones at the base of the MCP joint of the thumb Bones are contained within the tendon of flexor pollicus brevis muscle [Also one below the base of the MCP of the second, but don't worry]

Teres Major

Thick and rounded muscle Inferior border forms the inferior border of the lateral part of the posterior wall of the axilla Origin: Dorsal Surface of inferior angle of Scapula Insertion: Medial lip of intertubercular groove Action: Internal Rotation and Adduction of Shoulder Nerve: Lower Subscapular nerve [Note the subscapular] (- Comes from posterior and goes anterior - Inferior angle of scapula (posterior surface) to medial lip of intertubercular sulcus/groove - Lady between two majors - Internally rotates shoulder; can assist in abduction - Lower subscapular nerve) (Scapula to humerus = abduction (may not be primary action but involved) Rotator Cuff Muscles - Dynamic stabilizers of shoulder)

Elbow Extensors

Triceps Anconeus

The Acromioclavicular joint

[Plane synovial joint with 3 degrees of freedom Has a joint capsule and 2 major ligaments Primary function is to maintain the relationship between the clavicle and the scapula during the early stages of elevation. Elevation of the upper extremity is a combination of scapular, clavicular and humeral motion] (- Carococlavicular ligaments - when pulled - spins clavicle backwards? - Plane gliding synovial joint o 2 kinds of rotation/spinning - different axes o Rotation on coronal; spins on longitudinal/medial axis of body) Joint capsule A-C ligaments Intra-articular disc Coracoclavicular ligaments -- Ligaments run from the coracoid to the clavicle -- conoid (medial) -- trapezoid (lateral) [Capsule is weak and needs the ligs to reinforce...Sup/Inf AC ligs control horizontal stability...Superior is strongest CC ligs very strong, frequently the elbow will break before the ligs rupture...prevent superior dislocation of the acromion on the clavicle..most critical role is producing longitudinal rotation for full ROM of UE Disc varies in size, usually degenerates by 40] Movements - Axial rotation of clavicle (spin) - Rotation of the clavicle around a longitudinal axis [Occurs during elevation above 60 degrees...scap upward rotates and conoid / trapezoid ligs restrict motion...coracoid process of the scapula now pills downward...tugs coracoclavicular...result is a flip of the clavicle around the longitudinal axis...referrer to frequenlty with scaplohumeral rhythm ]

Posterior Thoracoappendicular Musculature

Superficial posterior muscles - Trapezius - Latissimus Dorsi Deep posterior muscles - Levator Scapulae - Rhomboids - Long head of triceps [This musculature is frequently referred to as the Superficial extrinsic back group] (Posterior = scapula muscles Posterior Thoracoappendicular Musculature - Superficial muscles and ones deep to them Superficial: trapezius and latissimus dorsi Deep: levator scapulae, rhomboids, long head of triceps)

Dorsal Musculature

Superficial: Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum communis Extensor digiti minimi Extensor carpi ulnaris [We've discussed all in the past lectures except the digiti minimi and the communis]

Anterior Thoracoappendicular Musculature

4 anterior thoracoappendicular muscles move the pectoral girdle - Pectoralis major - Pectoralis minor - Subclavius - Serratus anterior - Long head of biceps - Coracobrachialis

Divisions of the Brachial Plexus

6 Divisions Each trunk has two divisions Anterior divisions of the superior and middle trunks unite to form the lateral cord Anterior division of the inferior trunk continues as the medial cord Posterior divisions of all three trunks unite to form the posterior cord

humerus notes

(- Head (like head of femur) - 2 necks o Where smooth part ends = anatomical neck o Shoulder surgery - can't just remove head - surgical neck o Greater and lesser tubercle help determine side; lesser tubercle is anterior o Head of femur faces medially o Intertubercular groove - important tendon: biceps tendon o External rotation - can feel lesser tubercle; internal rotation - can feel greater tubercle; fingers touching shoulder are on intertubercular groove with biceps tendon coming through o Spiral/radial groove o Medial epicondyle is larger - what we call funny bone Medial - flexes origin Lateral - extensor origin `lateral epicondylitis - tennis elbow; - wrist extension • knitting Medial epicondylitis - golfer's elbow - wrist flexion o Flattening lower forms ridge = supracondylar ridge (lateral and medial) o Dimples allow forearm bones to attach Olecranon process of ulna Dimple on humerus -> olecranon fossa Coronoid process of ulna -> coronoid fossa • (coracoid = scapula; goes alphabetically) Lateral fossa = radial fossa o Lateral with head of radius = capitulum of humerus; (more rounded) o Medial articular surface with ulna bone = trochlea of humerus - Deltoid tuberosity - under greater tuberosity; triangular like gluteal tuberosity - Rotator cuff: On trochanters: supraspinatus, infraspinatus, teres minor (inferior) (there is a 4th) subscapularis ? o All attach to proximal end of shoulder o Rotator cuff tendonitis = inflammation of these tendons Muscles causing up and down; rotation are weak Scapula-humeral rhythm is weak Leads to encroachment of sub___ space -> impinchment - specifically the supraspinatus )

Scapulothoracic Joint

(- Protaction (abduction of scapula) - Retraction (adduction of scapula) - Upward rotation = glenoid facing upward - Downward rotation = glenoid facing down) The articulation between the scapula and the posterolateral corner of the thorax Scapula is suspended on the thorax by the scapulothoracic muscles Consists of two spaces: --space between the serratus anterior and scapula/subscapularis --space between serratus anterior and thoracic wall [Not a true anatomic joint due to the lack of fibrocartilaginous union] Orientation of the scapula... Scapula does not lie in the frontal plane Angled obliquely 30 degrees to the frontal plane --Clinically: "Scapular plane" is 30-45 degrees anterior to the frontal plane Resting Position -Medial Border is nearly vertical -Abducted approximatly 6cm from the spine -Anterior tilt of 20 degrees -Hand of dominance --Depressed, downward rotated, anteriorly tilted Scapulothoracic Motion -Elevation/depression -Protraction/retraction -Upward/downward rotation [Elev /Dep - cephelad or caudal Pro / Ret - sliding toward or away from the verteberal column Rotation - tilt the fossa up or down] Scapulothoracic Muscles Trapezius Serratus anterior Rhomboids Levator scapulae Pectoralis minor Subclavius Biomechanics of Scapular Rotation: Scapulothoracic motion that occurs involves: - A-C joint - S-C joint

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(- flat S shaped bone; medially convex; laterally concave when looking from front (anteriorly) - sternal end (medial; larger and more rounded) and acromial end (flat) - sternalclavicular joint o clavical articulates with manubrium at clavicular notch - AC joint: laterally - Landmarks: superior surface - not a lot of muscles attach there; able to be felt o Lateral end attachment: deltoid muscle; @ deltoid tubercle - Conoid tubercle: coracoclavicular ligament extends from coracoid process of scapula to clavicle o Has 2 bands: o Clavicle spins as you abduct o Has groove - subclavian (under clavicle) artery and vein Left subclavian artery - directly from aorta Right subclavian artery Attachment for subclavius muscle: mostly for stability - Lot of vasculature in that upper area o Some have extra rib- cervical rib; can compress o Or if injury here; can damage a lot)

Flexor Digitorum Superficialis (FDS)

(intermediate muscle) Travels Along the anteriormedial forearm O: medial epicondyle of humerus I: bodies of middle phalanges of medial 4 digits (2-5; middle phalynx) A: flexes middle phalanges at PIP joints of medial 4 digits I: median nerve (like other muscles for anterior compartment)

Triangular Fibrocartilage Complex (TFCC)

(looks triangular on top) Fibrocartilaginous articular disc "triangular ligament" (ulnar-carpal ligament sits on disc) Binds the ends of the radius and ulna together Is the main uniting structure of the joint [Also has an articular disc that is attached along the distal edge of the radius Disc is shaped like a triangle with the base at the radial ulnar notch and the apex attached to the styloid process of the ulna...main uniting structure for the joint Separates the joint cavity of the distal radio-ulnar from the cavity of the wrist ] (triquetrum - articulates with TFCC except for adduction (or ab?) when with true wrist joint?)

Radiocarpal Joint

(primarily between distal end of radius and scaphoid and lunate) Distal end of the radius and the articular disc of the distal radioulnar joint articulating with the proximal row of carpals - Except for the pisiform [Proximal joint lateral, medial and disc surface Lateral with the scaphoid Medial with the lunate Disc with the triquetrum Distal surface is the proximal carpal row of the scaphoid, lunate and triquetrium] Fibrous capsule surrounds the wrist joint and is attached to the distal ends of the radius and ulna and the proximal row of carpals (scaphoid, lunate, triquetrum) (NOT PISIFORM) Ligaments supporting the joint are the dorsal and palmar radiocarpal, the medial and the lateral [Remember the pisiform is part of the distal carpal row but does not participate in the articulation] Ligaments supporting the joint are the dorsal and palmar radiocarpal, the medial and the lateral The dorsal and palmar strengthen the joint capsule The medial goes from the styloid of the ulna to the triquetrial The lateral from the styloid of the radius to the scaphoid

Palmar Aponeurosis

(thickens ligaments?) Continuation of flexor retinaculum and palmar ligaments Continues toward the fingers and splits into 4 slips Attaches to the MCP and deep transverse ligament [Covers the soft tissues and overlies the flexor tendons of the hand Each slip is fused with the fibrous digital sheath and attaches at the bse of the proximal phalanx] shortening causes contraction: Dupuytren's contracture is a thickening of the fibrous bands to the finger flexors of the MCP's (can't extend fully; neurological issue or prolonged inability) [Pulls the digits into forceful flexion and they cannot be stretched]

Carpal Tunnel

- The Passage of the FDS, FDP and the FPL under the flexor retinaculum - Median Nerve also passes through the tunnel (formed between capral bones and flexor retinaculum; compression of medial nerve; sensory involvement on lateral aspect - lateral 3 1/2 fingers; pins and needles sensation; intrinsic muscles supplied by medial (pollucis) - leads to ape thumb deformity except abductor? supplied by ulnar nerve)

Pronator Teres

- Fusiform muscle - Two heads of proximal attachment (one at the common flexor tendon the other at the coronoid process of the ulna) - Forms the medial boundary of the cubital fossa O: medial epicondyle of humerus and coronoid process of the ulna I: middle of lateral surface of the radius A: pronates and flexes the elbow N: median

1st Axillary Division

- Lateral border of the 1st rib to the medial border of the pec minor - Gives off one branch - Superior Thoracic Artery

3rd Axillary Division

- Lateral border of the pec minor to the medial border of the teres minor - Gives off three branches - Subscapular, anterior humeral circumflex and posterior humeral circumflex (2nd divison runs with long thoracic nerve (3 divisions; know branches of each division))

2nd Axillary Division

- Medial to the Lateral border of the pec minor - Gives off two branches - Thoracoacromial & Lateral Thoracic

Arterial Supply

- The Subclavian arteries give off the Axillary arteries after they cross the clavicle (name changes) - Three Divisions of the Axillary Artery

Trapezius

- provides direct attachment of the pectoral girdle to the trunk - large, triangular shaped muscle - fibers are divided into three parts and serve three different actions Origin: External Occipital Protuberance, Spinous Processes of C7 through T12 Insertion: Distal clavicle, A-C joint and spine of the scapula Action: - Upper- elevates - Middle- retracts - Lower- depresses Upper and Lower work to upwardly rotate scapula Nerve: CN XI, spinal accessory nerve with contributions of C2, C3, C4 [All actions reference the Scapula The innervation is tested with by a shoulder shrug. Motor loss usually results in the atrophy of the upper and difficulty with elevation. CN XI easily tested with this muscel if there is suspected cranial nerve loss.] (- Fibers in all directions (3 orientations) o Upper, middle, and lower - Upper: elevate scapula - Mid: retraction of scapula - Lower: depress scapula - All involved in shoulder synergy - Spinous processes of C7 - T12 (midline of vertebral column) o Can't really distinguish O/I on cadaver; more likely to get action o Be specific as to whether upper, middle, or lower - Laterally attaches to acromium process, spine of scapula, and distal clavicle (but on the top of all of these) which causes upward rotation - 1 of 2 muscles not supplied by nerve from brachial plexus o Cranial nerves - 11th cranial nerve = spinal accessory nerve; supplies trapezius )

The Elbow Region : Arm and Forearm

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Shoulder Joint and Pectoral Girdle

.- Shoulder has a lot of mobility but not stable (can dislocate) - Scapula-humeral rhythm

Cords of the Brachial Plexus

3 Cords Lateral - Anterior division of the upper and middle trunk Medial - Anterior division of the lower trunk Posterior - Posterior divisions of all three trunks Give off the branches that become the peripheral nerves

Dorsal Musculature -Deep

Abductor Pollicis Longus Extensor Pollicis Brevis Extensor Pollicis Longus Extensor Indicis

The Elbow - Osteology

Anterior aspect: - Humerus - Ulna - Radius [Humerus is the largest bone in the upper limb...distally it articulates with the ulna medially and the radius laterally] Anteriorly and medially, the coronoid fossa receives the coronoid process of the ulna during flexion The shallow radial fossa receives the radial head during extreme elbow flexion Posterior aspect: - Olecranon - Olecranon fossa - Trochlear articular surface [Posteriorly the olecranon fossa receives the olecranon during extension] Radial head: Slightly oval - results in lateral displacement of radial head in full pronation The obliquity of the trochlea, the further distal projection of the medial portion of the trochlea, results in a cubital valgus ("carrying angle") [The carrying angle in men is less than that of women. Men about 5 degrees...women about 10-15 The carrying angle will disappear when the forearm is pronated the elbow in full flexio and extension] - The medial epicondyle of the humerus gives rise to the common flexor tendon for all flexor muscles in the superficial and middle anterior forearm compartments - The lateral epicondyle gives rise to the common extensor tendon for all superficial dorsal muscles except ECRL and Brachioradialis - In full elbow flexion the olecranon process, medial and lateral epicondyles should form an equilateral triangle - In full elbow extension these same landmarks lie in a straight line [All the muscles of the forearm can be divided into flexor-pronator and extensor-supinator groups. Extensor supinator group comes from the lateral epicondyle]

SGHL

Arises from the glenoid rim from approximately 1 o'clock and runs inferior and laterally Inserts on the anatomical neck near the medial ridge of the intertubecular groove, anterior to the greater tuberosity

MGHL

Arises from the glenoid rim from approximately 1 to 3 o'clock and runs inferiorly and laterally Inserts on the anatomical neck medial to the lesser tuberosity

IGHL

Arises from the inferior 2/3 of the glenoid rim and runs laterally From approximately 3:00 to 8:00 Inserts along the inferior 1/3 of the head of the humerus IGHL complex Anterior band, --A thickening which arises between 2 and 4 o'clock Posterior band --A thickening which arises from the glenoid rim between 7 and 9 o'clock Axillary Pouch --Inferior Support Inserts on the humerus below the lesser tuberosity

Coracohumeral ligament

Arises from the lateral end of the coracoid process and runs laterally splitting into two bands Anterior band blends with the subscapularis tendon to insert near the lesser tuberosity Posterior band blends with the supraspinatus tendon to insert near the greater tuberosity [Checks ER but is more important as a passive support to the limb against gravity]

Peripheral Cutaneous Nerves

Axillary Nerve (C5,C6) - From the posterior cord of the plexus -- Terminal Branch - Gives off the superior lateral cutaneous nerve of the arm and lateral shoulder [Terminal Branch of the Posterior cord Anterior terminal branch supplies the deltoid and the posterior branch supplies the teres minor and the posterior delt] - Runs posterior in the axillary fossa and then passes through the quadrangular space with the posterior humeral circumflex artery [Note the way the nerve winds around the surgical neck of the humerus Note the close relationship between the axillary nerve and the posterior humeral circumflex artery. The nerve/ artery relationship is a consistent theme in the upper extremity.] (Axillary Nerve: innervates deltoid, teres minor - Break in surgical neck of humerus -> might hit this nerve and/or posterior humeral circumflex artery) Musculocutaneous Nerve (C5-C7) From the lateral cord of the plexus Terminal Branch Supplies the lateral forearm when it becomes the lateral antebrachial cutaneous nerve (of the forearm) After supplying the muscular divisions it emerges laterally to the biceps [Coraco brachalis, biceps, brachialis] (Musclocutaneous Nerve: corticobrachialis - Lateral antebrachial cutaneous at forearm - Proximal injury: affect muscles and sensory - Distal injury close to elbow -> sensory of forearm)

Transverse Plane Force Couple

Balances the anterior cuff from the posterior cuff Damage to one of these muscles can result in anterior or posterior migration of the humeral head during shoulder movement the result will be abnormal shoulder biomechanics (- Anterior force with external rotation? - Posterior force with internal rotation?)

Structural Considerations

Bony Anatomy Labrum Capsuloligamentous structures [The glenoid is positioned lat, ant and slightly superior...it is concave in AP and inf/sup directions... The humeral head is 1/3 of a sphere and thus is not matched to the concavity of the glenoid...this results in an increased arc of motion, but decreased congruity of joint surfaces... Labrum increases this congruity The humeral head hangs on the lip of the glenoid.... If the scapula is downwardly rotated, it will dump the humeral head out of the glenoid and therefore, the scapula must rotate upward with UE movement to keep the humeral head in the glenoid... The labrum is a rim of fibrocartilage that is attached to the margin of the glenoid cavity...It serves primarily to deepen but also widens the glenoid cavity and improves the congruity of the GH joint...The periphery of the labrum is the site of attachment of the GH capsule... Medially the capsule is attached to the periphery of the glenoid and the labrum. Laterally the capsule is attached to the anatomical neck of the humerus. The inferior margin of the capsule may form a collar-like attachment along the anatomical neck or may descend somewhat down the shaft...]

Dermatomes of the Upper Extremity

C1- no innervation to skin C2- posterior aspect of head C3- posterior aspect of neck C4- acromioclavicular joint [This is important for sensory testing and identification of possible nerve root involvement] C4- acromioclavicular joint C5- lateral arm C6 lateral forearm, thumb, index finger and one-half of the middle finger C7- middle finger C8- ring finger, little finger and distal half of the forearm's ulnar side T1- medial side of the upper half of the forearm and upper arm [This is important for sensory testing and identification of possible nerve root involvement] (Dermatomes -> don't really need to memorize where they are but - Carry motor or sensory but not both o Dorsal -> carry sensory roots, into spinal cord o Ventral -> carriers motor roots out of spinal cord - Mytholopothy -> pinch nerve - A lot of things affected by C6 -> biceps, triceps - Ventral rami -> carry sensory and motor fibers anteriorally o (dorsal only go deep; don't care?) - Dermatome is sensory and myotome is motor - Roots from lab = rami Next few sides explain diagram made)

Dorsal /Extensor Compartments of the Wrist

Compartment 1: APL, EPB (lateral) Compartment 2: ECRL/ECRB Compartment 3: EPL (winds around distal tubercle; more medial) Compartment 4: EDC/EIP Compartment 5: EDM Compartment 6: ECU (medial) (all under extensor retinaculum from lateral to medial) (don't need to memorize compartments)

The Elbow - Myology

Compartments: Anterior-(flexor-pronator group) - Superficial - Deep Posterior-(extensor-supinator group) - Divided into three function groups [Many of the 15 muscles that cross the elbow, also act at either the wrist or the shoulder] Flexors of the Elbow - Brachialis - Biceps - Brachioradialis [1 is brachialis, 2 is brachioradialis, 3 is biceps]

Glenohumeral Motion

Convex - Concave Rule: Roll: Occurs in the same direction as the swing of the bone (angular displacement) When the convex surface is moving: -The joint surface glides in the direction opposite the swing of bone Convex vs. Concave When a convex surface moves on a stable concave surface, the glide of the convex surface is in the OPPOSITE direction of the bony lever. When a concave surface moves on a stable convex surface the glide of the concave surface is in the SAME direction as the movement of the bony lever. Convex vs. Concave Convex moving on Concave Roll and Glide are in opposite directions Concave moving on Convex Roll and glide are in the same direction (- Roll = spinning/rotating; glide = flat motion o Roll = same direction as bony motion o Glide = matters whether concave/convex) Glenohumeral Motion Controlled by: -Passive Restraints (- [Passive are the ligaments and the capslue... active is the musculature that is present]) -- Bony Geometry -- Glenoid Labrum -- Capsuloligamentous Structures -- Joint Pressure: Negative intra-articular pressure -Active Restraints -- The Rotator Cuff [Passive are the ligaments and the capslue... active is the musculature that is present] [EMG shows all muscles of the shoulder are electrically silent when the shoulder is at rest Stability has to be passive...superior capsule and the coracohumeral ligament...when loaded the supra kicks in] (- Active restraints - External rotators = anterior - Internal rotators = posterior)

Frontal Plane Force Couple

Deltoid exerts an upward force on humerus during abduction which is balanced by the action of the rotator cuff Rotator Cuff Function in Frontal Plane Force Couple Approximates humerus into the glenoid Supraspinatus assists deltoid in abduction Subscapularis, infraspinatus & teres minor depress humeral head Disruption of supraspinatus does not disrupt coronal plane force couple Normal function of arm still possible dependent on status of remaining RC Disruption of the frontal plane force couple results in superior migration of humeral head Disruption of force couples occurs as a result of weakness, tear or paralysis of subscapularis, infraspinatus and/or teres minor

Joints of the Wrist

Distal Radioulnar Joint Radiocarpal Joint Triangular Fibrocartilage Complex (TFCC)

The Wrist - Osteology

Distal Radius Distal Ulna The Carpals [Joints proximal to the wrist serve to increase ability to manipulate the hand in space The Carpus - primary function of hand placement is not goal The entire upper limb essantially serves the hand and it's functions...any loss fo function in the upper limb will ultimately translate into lost function at the hand. Wrist as a whole is bi-axial...motions are flexion/extension and radial and ulnar deviation The radius is the larger of the 2 articulations at the wrist...ulnar head being the smaller and more medial]

Interossei

Dorsal Interossei (1-4) O: Adjacent sides of two metacarpals I: Extensor expansions of bases of proximal phalanges of digits 2-4 A: Abduct digits (DAB) N: Deep branch of ULNAR nerve Palmar Interossei (1-3) O: Palmar surfacess of 2nd, 4th, and 5th MCs I: Extensor expansions of digits and bases of proximal phalanges of digits 2, 4, and 5 A: Adduct digits (PAD) I: Deep branch of the ulnar nerve

Extrinsic Ligaments

Dorsal Ligaments -Dorsal Radiocarpal -Dorsal Ulnocarpal -Radial Collateral (lateral) -Ulnar Collateral (medial) [DRC passes from radial styloid to the lunate and the triquetrium...capsular thickening...maintain contact between the lunate and the radius DUC from Ulna to triquetrium Collaterals are intracapsular ligaments...RC passes from the radius to the scaphoid and the trapezium...UC from ulna to the pisiform and the triquetrium...controls passive radiocarpal motion in the frontal plane] Palmar Ligaments -Radiocarpal ligaments -- Radioscaphoid -- Radiocapitate -- Radiotriquetral -Ulnocarpal ligaments -- Ulnolunate -- Ulnotriquetral -TFCC [Name is the address RT is the strongest and the stiffest of the three...RC/RS check joint motion and maintain integrity Ulno from the TFCC...bands to the lunate and the capitate]

Clavicle (Collar Bone)

Doubly curved ("S" shaped) long bone Two ends: Medial (sternal end) Lateral (acrominal end) Medial 2/3 of the body (shaft) is convex anteriorly Lateral 1/3 is concave anteriorly [Image is a right clavicle Easy to palpate] Sternal End Enlarged and triangular Articulates with manubrium Forms the SC joint (sternoclavicular) [Image is a right clavicle SC is a saddle joint] Acromial End Flat Articulates with acromion (scapula) Forms the AC joint (acromioclavicular) [Image is a right clavicle AC is a plane gliding joint] Superior Surface Just deep to the skin - Can palpate the entire length Landmark: Deltoid tubercle- prominence indicating the attachment of the deltoid [Image is a right clavicle More on the inferior surface rather than the superior] Inferior surface rough (for ligamentous attachments) Landmarks: Conoid tubercle for medial portion of coracoclavicular ligament Subclavian groove For attachment of subclavius muscle Impression for costoclavicular ligament Binds first rib to clavicle Trapezoid line for lateral portion of coracoclavicular ligament [Image is a right clavicle More on the inferior surface rather than the superior Subclavius attaches to the groove and to the junction of the 1st rib] Function: -connects upper limb to trunk -serves as a rigid support from which the scapula and upper limb are suspended -keeps arm away from thorax for mobility -moveable to permit the scapula to move on the thoracic wall (ST joint/articulation) -Forms bony boundary of cervicoaxillary canal (passage between neck and arm) -Protects neurovascular bundle -Transmits shocks from the upper limb to the axial skeleton

The Hand - Extensor Mechanism

Expansion of the extensor digitorum tendons to digits 2-5 Secures the extensor digitorum to the digit Provides extension of the MP and IP joints Consists of central slip and 2 lateral bands (central band from extrinsic tendons and lateral band - lateral interrosei;) [The mechanism is made up of the Ed tendon, the connective tissue expansions, and fibersfrom the tendons of the interossei and the lumbricals of each finger] Deformities related to damage of the extensor hood mechanism (central tendon ruptured; catch basketball - hits finger; gets caught) -Mallet finger --Terminal band is avulsed --Loss of active DIP extension (flexes instead) [Can frequently be associated with an avulsion fracture] - Swan Neck Deformity --ORL destroyed --Leads to dorsal displacement of the lateral bands (gets ruptured; migrate above and hyperextends so flex at DIP) --Causes hyperextension at the PIP and flexion at the DIP -Boutonniere Deformity -- Loss of the central tendon and transverse retinacular ligament (tendon or extensor expansion ruptured; flexion of PIP and extension at IP) -- Lateral band slide volarly and result in PIP flexion with DIP hyperextension

Musculotendinous Structures

Extrinsic system- muscles originating outside the wrist and inserting within the wrist or hand Superficial and deep muscle divisions Intrinsic system- muscles originating and inserting within the wrist and hand Normal function of the hand require precise timing and coordination of the two systems [We'll cover the extrinsic musculature here in the wrist and the intrinsic when we get to the hand]

Ligaments

Extrinsic- extracapsular ligaments that course between the carpal bone(s) and the radius or the metacarpals -- Provide stability to the proximal and distal rows by binding them to the radius and the ulna Intrinsic- ligaments that originate and insert on the carpus

Movements of the Shoulder

Flexion: 150-180 degrees Extension: 50-60 degrees Abduction: 180 degrees External Rotation: 90 degrees Internal Rotation: 70-90 degrees Horizontal Abduction Horizontal Adduction (combination of flexion/extension and ab/adduction - On horizontal plane instead of frontal plane)

Deep

Flexor Digitorum Profundus (deep to superficialis) Flexor Pollicis Longus Pronator Quadratus (none from medial epicondyle) (actions at wrist or forearm itself)

The Shoulder and Pectoral Region (2)

Force couples are muscles balanced against one another to insure humeral head stays centered in the glenoid fossa and does not cause subacromial impingement General force couples of the shoulder include: - Frontal plane force couples - Transverse plane force couples

Rhomboids

Form an oblique equilateral parallelogram Lie deep to the trapezius

Glenoid Fossa

Forms the concave surface of the glenohumeral joint Much smaller than the head of the humerus Faces laterally, superiorly and anteriorly Supraglenoid tubercle serves as site of attachment for long head of the biceps [For the fossa to face in this direction, note the scapula does not lie in the true frontal plane at rest... Curvature of the fossa is greater in the frontal plane than in the saggital plane Majority of the time the humeral head only rests on a small inferior portion of the fossa] (- Concave surface - Tubercles: for triceps? - Glenoid labrum like acetabular labrum - deepens socket o Supraglenoid tubercle on top - long head of biceps o Gets fibers from superior part of labrum SLAP lesion - can be seen with biceps injury)

Ulnar Nerve (C8-T1)

From the medial cord of the plexus - Dorsal Posterior Cutaneous - Palmar Cutaneous Branch [Skin on the medial palm] Descends in medial arm - Medial Epicondyle - Medial Forearm: FCU and FDP - Guyons Canal: Hook of the Hamate [Larger Terminal Branch of the medial cord. Emerges from between the FCU and the FDP in the distal third of the forearm and divides into the palmar and dorsal branches] (- Only supplies one whole muscle in forearm - Does most of nerves in hand - Has dorsal and palmar branches -> both side of hand o To half of ring finger - Medial -> wraps around medical epicondyle (most common place for injury) o FCU and FDP o Under hook of hamate o Can get pinched)

Median Nerve (C6-T1)

From the medial cord of the plexus - Palmar Cutaneous Branch -- Digital brnaches to the palmar surface of the lateral three and ½ digits -- Articular branches to the elbow, wrist and carpals Formed by branches from the medial and lateral cords -- Over the Axillary artery -- Descends with the Brachial Artery -- Cubital Fossa [M formed on the lateral surface of the artery. The tip of the "M"] Cubital Fossa -- Nerve has crossed in front of the artery and now lies medial to it --Continues into the hand through the carpal tunnel to supply the lateral 3.5 digits [Passes under the pronator teres, FCR, PL and FDS. Continues in the forearm between the FDS and the lateral portion of the FDP Right before it passes under the FDS it throws off a branch called the AIN that travels along the interosseus membrane] (- Palm and first 3 ½ fingers - Cubital fossa (everything done) -> pronator teres (might still have some pronation) -> Carpal tunnel (just affects hand) - Anterior interroseus nerve o Only motor o Radial half of FDP/B, FHL, PQ) (Wrist drop -> where on radial nerve is injured Usually humeral shaft fracture Happens higher Posterior interosseous nerve (PIN) - deep branch -> supinator syndrome - Also affective by wrist drop; all deep extensors - Happens at supinator or below) (Ape hand - Thumb won't move - High lesion (near cub___ fossa) can affect wrist function AIN - FPL = flexes IP of thumb o If have nerve, can make ok with hand Claw Hand - Ulnar nerve; denerved FCU - Only lumbricles 3&4)

Radial Nerve (C5-T1)

From the posterior cord of the plexus Give cutaneous distribution through Posterior brachial cutaneous Inferior lateral brachial cutaneous Posterior antebrachial Superficial branch and the dorsal digital branch [Skin of the posterior and inferolateral forearm and the dorsal 3.5 digits except the tips (Median Nerve)] [Lots of muscles - check your book, we'll go over them later] Exits the Axilla: Posterior to Axillary Artery Radial Groove: Deep Brachial Artery Lateral Intermuscular Septum Cubital Fossa [Ax Art posterior to the humerus in the radial groove with the deep brachial Between the lateral and medial heads of the triceps and perforates the lateral intermuscular septum and enters the cubital fossa] Enters the Cubital Fossa Divides into the - Deep: Motor division - Superficial: Cutaneous division (- All posterior - Also triceps, biceps, some flexors - Flips - On top: sensory and motor running together - Radial groove with deep brachial artery - Break shaft of humerus/compression - Splits in forearm o Superficial -> gonna do thumb, back of hand o Deep -> supinator, extensor radialis brevis Becomes posterior interosseous nerve - Damage before supinator -> lose sensory and motor - Below supinator: deep = motor only; still have sensory)

Brachioradialis

Fusiform muscle Lies superficially on the anteriolateral surface of the forearm Forms lateral border of the cubital fossa Located in posterior elbow compartment [Brach - pronator - FCR - FCU] O: proximal 2/3 of the lateral supracondylar ridge of the humerus I: lateral surface of distal radius A: flexes forearm N: radial nerve

Extensor Carpi Radialis Longus

Fusiform muscle overlapped by the brachioradialis O: lateral supracondylar ridge of the humerus I: base of the 2nd MC A: extends and abducts (radially deviates) the wrist N: radial nerve

Extensor Carpi Radialis Brevis

Fusiform muscle which is shorter than the longus O: lateral epicondyle of humerus I: base of the 3rd MC A: extends and abducts wrist N: deep branch of radial nerve

Biceps

Fusiform muscle with two heads Two muscle bellies unite just distal to the middle of the arm O: short head- tip of the coracoid process of the scapula. Long head - Superior glenoid tubercle I: radial tuberosity A: flexes forearm; most powerful supinator of the forearm N: musculocutaneous [Remember the long head is encapsulated at the shoulder]

The Shoulder Girdle

G-H joint A-C joint S-C joint S-T joint Subacromial space Glenohumeral - Articulation between the glenoid fossa and the humeral head Acromioclavicular - Articulation between the acromion of the scapula and the clavicle Sternoclavicular - Articulation between the sternum and the clavicle Scapulothoracic - Articulation between the scapula and the thoracic cage Subacromial space - Space between the acromion and the humeral head Associated ligaments] The Glenohumeral Joint: The articulation of the glenoid surface of the scapula with the head of the humerus Classified as a spheroidal (ball and socket) joint Multi-axial and has three degrees of freedom [Again we are sacrificing stability for mobility] (Sternoclavicular Joint: articulates with manubrium actually has 2 directions of motion True joint of shoulder = glenohumeral joint: between glenoid fossa and humeral head Under acromium = sub acromial space -> lots of tendons run there Scapular should contribute 1/3 of motion Encroaches on sub acromial space if scapula doesn't move GH = ball and socket type of joint Head faces medially and posteriorly; glenoid faces anteriorly Greater and lesser tubercle; Intertubercular sulcus: Long head of biceps is felt when rotating shoulder; holds ligament down)

The Humerus of shoulder girdle

Head is the convex joint surface Approximately 1/3 of a sphere The head faces medially, posteriorly and superiorly The anatomical neck of the humerus separates the humeral head from the remainder of the epiphysis [The axis through the humeral head and the longitudinal axis may be anywhere between 130 - 150 degrees in the frontal plane... this is referred to as the angle of inclination In the transverse plane the axis through the humeral head and the condyles create the angle of torsion] Anatomical neck serves as the site of attachment for the glenohumeral joint capsule Lateral to the anatomical neck are the greater and lesser tubercles [The capsule is twice the size of the humeral head...the capsule is weakest inferiorly, but the weakness is most apparent in the anterior direction since forces are more likely to thrust the humeral head forward Attached medially to the glenoid cavity, beyond the labrum...laterally the capsule attaches to the anatomical neck of the humerus...superiorly it attaches on to the coracoid process, enclosing the long head of the biceps within the capsule Synovial membrane lines the fibrous capsule] Greater tuberosity serves as the site of attachment for the supraspinatus, infraspinatus and teres minor [The attachment points of each muscle will determine action Supra - on the superior facet - abductor Infra - middle facet, but comes from posterior - ER Teres Minor - Inferior facet, again from posterior ER Lesser...more anterior...Subscap passes anterior to the fossa and inserts on anterior surface...IR Gorrve is for the Tendon of Long Head...through an opening in the anterior capsule] The lesser tuberosity serves as the site of attachment for the subscapularis Tubercles separated by the intertubercular groove [The attachment points of each muscle will determine action Lesser...more anterior...Subscap passes anterior to the fossa and inserts on anterior surface...IR Groove is for the Tendon of Long Head...through an opening in the anterior capsule] (- Surgical neck and artery (circumflex) - issue that are very close o Axillary region o Crutches, accidentally nick, etc - Quadrangular space: o Borders: teres major and minor)

Joints of the Hand

Intercarpal Joints Midcarpal Joint Carpometacarpal Joints (CMC) Metacarpalphalangeal (MCP) Proximal Interphalangeal (PIP) Distal Interphalangeal (DIP) (joints between carpal = inter; between carpal and MC = meta;

Adductor Pollicis

Intrinsic O: Oblique head- bases of 2nd and 3rd MCs; Transverse head- anterior 3rd MC I: Medial side of base of proximal phalanx of thumb A: Adducts thumb N: Deep branch ulnar nerve (AIN?) (Only pollucis by ulnar nerve) also has I: Ulnar side of base of proximal phalanx of thumb [Through the ulnar sesamoid]

The Sternoclavicular Joint

Joint capsule Anterior & posterior S-C ligaments Intra-articular disc Interclavicular ligament Costoclavicular ligament [Saddle synovial joint...Only structural attachment to the rest of the body...capsule is strong, but still depends on ligs for stability A/P ligs check A/P motion of head Disc separates the incongruent joint surfaces...continuous with the A/P ligs IC extends across the jugular notch of the sternum...checks excessive depression or downward glide of the clavicle CC is very strong ligament and provides substantial stability...axis for elevation and depression...main check to clavicular elevation and superior glide] (- Saddle synovial joint (sometimes plane gliding) o Anteriorly = convex o Posterior = concave - Interclavicular ligament - Sellar joint = saddle joint - Elevation and depression of shoulders; protraction/retraction; axial rotation (spin)) Sellar joint: Sup/inf -- Proximal clavicle: convex -- Manubrium: concave Ant/post --Proximal clavicle: concave --Manubrium: convex Sternoclavicular Joint Motions -Protraction/retraction -Elevation/depression -Axial rotation (spin) [Protraction: ant roll and ant glide Elevation: sup roll and inferior glide Spins posterior from neutral to allow UE elevation...30-45 degrees]

The Humerus

Largest bone of the upper limb Ball-shaped head of the humerus articulates with glenoid fossa of the scapula (Glenohumeral joint) Distal humerus articulates with and radius and ulna creating the Humeroulnar and Humeroradial joints Humerus - Landmarks: Head Anatomical neck Body Greater tubercle Lesser tubercle Capitulum Trochlea Intertubercular groove Surgical neck Deltoid tuberosity Medial supracondylar ridge Coronoid fossa Radial fossa Lateral supracondylar ridge (crest) Medial supracondylar ridge (crest) Medial epicondyle Lateral epicondyle Olecranon fossa Radial groove anatomical neck is a line separating tubercles from head of humerus greater tubercle is lateral margin of humerus and can be divided into three facets for attachment of rotator cuff - Supraspinatus - Infraspinatus - Teres Minor lesser tubercle projects anteriorly from bone [Supra is SA, Infra post, Teres Post inf] - greater and lesser tubercles are separated by a bicipital groove. (Intertubercular groove) - distal to the tubercles the shaft narrows and this is the surgical neck (propensity to fracture) - the body of the humerus has the deltoid tuberosity (laterally) for attachment of the deltoid muscle and the Radial (spiral) groove, which is site for finding radial nerve and brachial artery [Groove for the tendon of the biceps as it goes intracapsule to the supra glenoid tubercle] -The inferior end of the humerus widens and flares into lateral and medial supracondylar ridges ending in prominent medial and lateral epicondyles -Laterally, the distal articulation, the capitulum, is the articular surface for the radius --Anteriorly the radial fossa receives the head of the radius during flexion - Medially, the distal articulation, the trochlea, is the articular surface for the ulna --Anteriorly, the coronoid fossa receives the ulna during full flexion of the elbow --Posteriorly, the olecranon fossa receives the olecranon fossa of the elbow during full elbow extension

Downward Scapular Rotation

Levator scapulae - Elevates and downward rotates Rhomboids - Retractrion and downward roatation Latissimus dorsi - Compresses the scapula to the thoracic cage Pectoralis minor - Draws the scapula anterior and inferior [Levator - Elevates and downward rotates Rhomboids - Retract and downward rotate Lats - Action on the humerus primarily, keeps the scapula in position on the thoracic cage during motion Pec minor - Draw scapula anterior and inferior]

Capsuloligamentous Structures

Medially, the capsule is attached to the periphery of the glenoid and glenoid labrum Laterally, the capsule is attached to the anatomical neck of the humerus [As before, superiorly it encroaches on the coracoid process, enclosing the origin of the long head] Posterior capsule is very thin Anteriorly, the glenohumeral joint is reinforced by three bands or thickenings of the capsule Inferior margin of the capsule may form a collar-like attachment along the anatomical neck Inferior portion is loose and redundant with the arm at the side of the body --This becomes tight and stretched out at the end range of elevation [Inferior portion of the capsule is the weakest...protected from above by the arch More specifically, abduction tightens the capsule Inferior portion is referred to as the axillary pouch] Axillary Pouch - formed by synovial membrane and capsule around - Leaves joint able to dislocate - Needed for movement o Especially abduction)

The Hand

Metacarpals:I, II, III, IV, V Phalanges - There are 14 -- Thumb only has 2 (others 3)

Flexor Carpi Ulnaris

Most medial of the superficial flexor muscles Only muscle of the anterior compartment- fully innervated by the ulnar nerve 2 Heads of origin O: Humeral Head: Medial epicondyle (common flexor origin) O: Ulnar Head: Olecranon and the posterior border of the Ulna I: Pisiform, Hook of the Hamate, base of the 5th metacarpal N: Ulnar Nerve A: Flexes and Adducts (ulnar deviates) the hand at the wrist

The Shoulder and Pectoral Region

Muscle Synergy: muscles acting in concert in a particular firing sequence to produce a specific sequence of movements These synergies involve force couples - muscles that acting alone produce one movement, but when coupled produce a different movement Synergies at the shoulder include: - Upward scapular rotation - Downward scapular rotation (: performing the same activity (same end result) such as abduct shoulder Upward and downward rotation of scapula are most important (more than protraction/retraction) Frontal Plane Force Couple: between abductors and supraspinatus Pushing head of deltoid down indirectly Pulls head of humerus up (equilibrium) (imbalance between muscles; supraspinatus stronger than deltoid; pulls head to high up))

Terminal Branches of the Brachial Plexus

Musculocutaneous : Lateral Cord (C5,C6,C7) Axillary : Posterior Cord (C5,C6) Radial : Posterior Cord (C5-8, T1) Median : Medial and Lateral Cord (C5-8, T1) Ulnar : Medial Cord (C7,C8,T1)

Scapular Rotation

Necessary to: -Enhance glenohumeral stability -Elevate acromion to avoid impingement -Maintain effective length tension relationship of scapulohumeral muscles

Opponens Pollicis

O: Flexor retinaculum I: Lateral side of 1st MC A: Draws 1st MC laterally and rotates it medially for opposition N: Recurrent branch of median nerve

Abdcutor Pollicis Brevis

O: Flexor retinaculum I: lateral side of base of proximal phalanx of thumb A: abducts thumb and helps with opposition N: recurrent branch of MEDIAN NERVE [Loss of this muscle from median nerve injury will result in the loss of opposition Most superficial and lateral of the thenars] [Deep and medial to the AbPB]

Opponens digiti minimi

O: Hook of hamate and flexor retinaculum I: Medial border of 5th MC A: Draws 5th MC anteriorly and rotates it bringing digit 5 into opposition with the thumb N: Deep branch of ulnar nerve [Deep to the Abductor and the Flexor]

Flexor digiti minimi

O: Hook of hamate and flexor retinaculum I: Medial side of the base of proximal phalanx of little finger A: Flexes proximal phalanx of digit 5 I: Deep branch of ulnar nerve [Lateral to the Abductor Digiti Minimi]

Extensor digitorum

O: Lateral Epicondyle of the Humerus I: Extensor expansions of the medial 4 digits A: Extends medial 4 digits at the MCP's and the IP's via the extensor mechanism; wrist extension. N: PIN

Extensor digitorum communis

O: Lateral Epicondyle of the Humerus (common extensor origin) I: Extensor expansions of the medial 4 digits A:Extends medial 4 digits at the MCP; extends hand at wrist N: PIN (extension of all digits; form extension expansion)

Lumbricals 3&4

O: Medial three tendons of the FDP I: Lateral sides of extensor expansions of digits 4&5 A: Flex digits at the MCP and extend the IP N: Deep branch of the ULNAR Nerve

Abductor digiti minimi

O: Pisiform I: Medial side of base of proximal phalanx of little finger A: Abducts digit 5 N: Deep branch ulnar nerve [Most medial of the hypothenars]

Extensor Pollicis Brevis

O: Posterior radius I: base of proximal phalanx of thumb A: extends proximal phalanx of thumb at CMC N: PIN

Abductor Pollicis Longus

O: Posterior ulna I: base of 1st MC A: abducts thumb & extends it at the CMC N: PIN (most proximal?)

Extensor Pollicis Longus

O: Posterior ulna I: base of distal phalanx of thumb A: extends distal phalanx of thumb at MCP and IP joints N: PIN

Extensor Indicis

O: Posterior ulna I: extensor expansion of 2nd digit A: extends 2nd digit at the MCP and the IP's via the extensor expansion N: PIN

Flexor Digitorum Profundus

O: Proximal ¾ of ulna I: bases of distal phalanges 2-5 A: flexes distal phalanges (superficialis does medial phalanges) N: digits 2&3- median digits 4&5- ulnar (dual nerve supply)

Flexor Pollicis Longus

O: anterior radius I: base of the distal phalanx of the thumb A: flexes phalanges of the thumb N: AIN- from Median (IF AIN injured - isolated - only cause weakness to 2 muscles of AIN; other median nerves spared - won't have weakness to wrist flexion but weakness to pronation of forearm and flexion of thumb) (crosses wrist but primary action is clearly not wrist flexion)

Pronator Quadratus

O: anterior surface of distal ulna I: anterior surface of distal radius A: pronates forearm N: anterior interosseous nerve from the median nerve

Extensor digiti minimi

O: lateral epicondyle of humerus I: extensor expansion of 5th digit A: extends 5th digit at MCP and IP joints N: PIN [Rarely absent but is sometimes fused with the ED]

Extensor digiti minimi

O: lateral epicondyle of humerus (common extensor origin) I: extensor expansion of 5th digit A: extends 5th digit at MCP and IP joints N: PIN

Lumbricals 1&2

O:Lateral two tendons of the FDP I: Lateral sides of extensor expansions of digits 2&3 A: Flex digits at the MCP and EXTEND the IP N: MEDIAN Nerve [LOAF : Mnemonic to remember the muscles of the hand innervated by the median nerve Lumbricals 1&2, Opponens Pollicis, Abductor Pollicis Brevis, Flexor Pollicis Brevis]

Picture with 4 fingers

Ok so here's a way to remember this Note the median nerve and its proximity to the palmaris longus on the lateral side Hand starts at medial epicondyle: four fingers spread on forearm flexor carpi ulnaris = pinky palmaris longus = ring flexor carpi radialis = middle pronator teres = index distal wrist crease, palmaris longus tendon, sit of median nerve

Rhomboid Major and Minor

Origin: C7 and T1 spinous processes (minor) T2 through T5 spinous processes (major) Insertion: medial border of scapula below the spine Action: Scapular Retraction, downward rotation Nerve: Dorsal Scapular nerve [Minor is superior to the major] (- Attach to vertebral column (same except for origin) - Rhomboid minor: Attaches to root of spine of scapula (or even slightly above it) o Then goes to spinous processes of C7 and T1 - Anything below attaches to spine of scapula = rhomboid major - Dorsal scapular nerve o Comes out of brachial plexus )

Short Head of the Biceps

Origin: Coracoid Process Insertion: Radial Tuberosity (with long head) and bicipetal apeneurosis Action: Elbow flexion, shoulder flexion Nerve: Musculocutaneous nerve [Note the Musculocutaneous goes to most of the flexors of the arm Pierces to Coracobrachalis on its way to the biceps] Remember the attachment of long head of the biceps is in the capsule and the short head is outside it (- All same except originates from coracoid process - On anterior side -> will shoulder flex - Primary: still elbow flexion)

Long Head of the Triceps

Origin: Infraglenoid tubercle Insertion: Olecranon process (with the rest of the triceps) Action: Main extensor of the forearm, extension and adduction at the shoulder Nerve: Radial nerve [The name indicates it has three proximal heads of attachment lateral and medial head lat and medial origins are the sup and inf radial groove Remember the biceps is the superior glenoid tubercle cocontraction for fossa stabilization] (- 3 heads: Long head is only muscle that originates proximal to shoulder joint - Extend elbow: primary action - Attaches to olecranon process - Radial nerve Long Head - Under glenoid fossa -> infraglenoid tubercle - Travels laterally and inferiorly at olecranon process with rest of triceps that have formed a tendon - Also assists in extension of shoulder - Helps with adduction of shoulder Quadrangular space: - Triceps = medial border - Surgical head of neck forms lateral border - Inferior border = teres minor; teres major = superior border)

Infraspinatus

Origin: Infraspinous fossa Insertion: middle facet of Greater Tuberosity Action: External rotation of shoulder Nerve: Suprascapular nerve [Works in conjunction with the other RC to compress the GC increasing joint congruity] (- Externally rotates shoulder - Suprascapular nerve - Much stronger external rotator)

Subscapularis

Origin: Subscapular fossa Insertion: Lesser Tuberosity Action: Internal rotation of the shoulder Nerve: Upper and Lower Subscapular nerves (Suprascapular nerve supplies abductor and external rotator (supraspinatus and infraspinatus) - Weak abductor and strong external rotator - Infraspinatus is stronger external rotator) (Axially nerve supplies abductor and external rotator (deltoid and teres minor) - Strong abductor and weak external rotator - Deltoid is strong abductor Subscapularis - Internal rotator (strongest) - Anterior? - Subscapular fossa to lesser tuberosity - Upper and lower subscapular nerves o Like teres major (primary action = internal rotation) Internal rotation is weak: upper or lower subscapular nerves (possibly both))

Long Head of the Biceps

Origin: Supraglenoid tubercle Insertion: Radial Tuberosity (with short head) and bicipetal apeneurosis Action: Elbow flexion, shoulder flexion Nerve: Musculocutaneous nerve Important as an anterior capsular stabilizer as the capsuloligamentous stability decreases (- Supraglenoid tubercle - Comes out capsule - covered in synovial fluid - Attach: radial tuberosity, biceptal apeneurosis - Can flex elbow, shoulder flexion, strong supination o Biceps curls - arms are in supination)

Supraspinatus

Origin: Supraspinous fossa Insertion: Superior facet of Greater Tuberosity Action: Assists Deltoid in abduction of shoulder Nerve: Suprascapular nerve [Secondarily it functions to compress the GH Suprascapular nerve from the superior trunk. Point out omohyoid] (- Primary action: - Initiation of abduction (first 15 degrees) o Deltoid does rest o Ex: slightly weak abduction o Can hold arms out (like a T) but then gets to final 15 degrees - collapses arms fast; this muscle; - deltoid good, supra bad o Or can't abduction at all - both not good o Can't abduct more than 15 degrees - deltoid bad, supra good o Bring up arms to 30 degrees and then can abduct - deltoid good, supra not - Called the drop arm test - Suprascapular nerve o Suprascapular notch)

Deltoid

Origin; Distal 1/3 rd of clavicle, A-C joint, spine of scapula Insertion: Deltoid tuberosity Action: Abduction of the shoulder Nerve: Axillary Nerve Thick and powerful Coarse textured Forms rounded contour of the shoulder [From the Greek Delta it's shaped like a delta Can be divided into anterior middle and posterior Anterior part is a strong flexor and medial rotator of the humerus Middle is the chief abductor of the shoulder Posterior is a strong extensor and lateral rotator of the humerus Usually works in conjunction with other muscles when performing these movements Fracture of the surgical neck of the humerus can cause atrophy of the deltoid b/c of damage to the axillary nerve] (- Triangular - 3 origins of fibers like trapezius o Anterior from clavicle; - flex shoulder o lateral from acromium process/AC joint; most important fibers/ if asked about muscle - this is primary function abduction - most important abductor of AC joint o posterior from spine of scapula - extend shoulder - Inserts - deltoid tuberosity - v shaped roughening on lateral aspect of humerus - Axillary nerve)

The Hand

Part of the upper limb distal to the forearm Contains the carpals, metacarpals and phalanges Comprised of the wrist, palm, dorsum of the hand, fingers and thumb. (- Intercarpal, carpal, metacarpal, metacarpalphalangeal joint, interphalangeal joints in thumb and digits - Thumb is 1(lateral); pinky is 5 (medial) - Ab/adduction = middle finger is midline (ignore thumb) - Thumb is in oblique plane: start with hands up o Ab/adduction; abduction looks like forward motion; adduction is back into up and down (these occur on sagittal plane); o flexion = across to palm; extension = back to normal)

The Pectoral Girdle

Pectoral Girdle: incomplete bony ring formed by the scapulae and the clavicles Anteriorly the clavicles are attached to the sternum at the manubrium Posteriorly the girdle is connected to the thorax via the muscular scapulothoracic "false" joint Often referenced as an articulation [The sternum is not part of the pectoral girdle The articulation traditionally referred to as the shoulder is actually part of the pectoral girdle] [Anterior view of the pectoral girdle] (- Incomplete circle; have to voluntarily move - Sternoclavicular joint -> acromialclavicular joint -> glenoid __ (true shoulder joint) -> - Scapula needs to move into elevation and depression - Scapula thoracic articulation)

The Phalanges

Phalanges are miniature long bones with a concave base that articulates with metacarpal and head that has an articular surface that resembles the condyles of the femur There are 5 proximal phalanges, 4 middle phalanges and 5 distal phalanges Each distal phalanx flattens into a nail bed (- 3 for each finger; 2 for thumb - Metacarpal phalangeal joints - Primarily condyloid o Flexion/extension; ab/adduction)

Distal Radioulnar Joint

Pivot type of synovial joint Rounded head of the ulna articulates with the ulnar notch on the medial side of the distal end of the radius (perform pronation and supination as distal radius moves across ulna) Enclosed by a fibrous capsule that is deficient superiorly - Accomodates the twisting of the capsule during supination [Functionally linked with the proximal radio-ulnar joint...when one moves, so does the other Also has an articular disc that is attached along the distal edge of the radius Disc is shaped like a triangle (TFCC) with the base at the radial ulnar notch and the apex attached to the styloid process of the ulna...main uniting structure for the joint Separates the joint cavity of the distal radio-ulnar from the cavity of the wrist ] [2nd pic -> focus on the disc here] Dorsally, Lister's tubercle protrudes near the center of the radius This serves as a pulley for the extensor pollicus longus (EPL) [ - on ulnar side of Lister's tubercle contains EPL, which defines ulnar border of anatomic snuff box; - at point where EPL passes dorsal radial tubercle (Lister's), tendon takes a 45 deg turn around tubercle; - then after passing over ECRL & ECRB tendons of tunnel II, it continues along its course to the thumb; offers mechanical advantage - if dorsal radial tubercle has been disrupted by Colles Frx (producing irregularity of process), EPL tendon may rupture due to added friction imposed upon it as it turns around roughned tubercle; - Lister's tubercle which is key to identifying both dorsal wrist ganglia & junction of scapholunate joint & dorsal scapholunate interosseous ligament; ] [Reinforced by the anterior and posterior radioulnar ligaments Interosseus membrane also provides stability for the proximal joint as well as the distal and by Palmar / Dorsal radiounlar ligaments; gives static stability]

The Hand - Nerve Lesions

Radial - Results in a drop wrist with a high radial nerve palsy Usually the result of a humeral shaft fracture Damage occurs proximal to the extensors of the wrist [Digits remain flexed and the wrist is flaccid] PIN - Deep branch of the Radial Nerve - Difficulties with radial and ulnar deviation and wrist extension - Sometimes called supinator syndrome because that's the site of entrapment [Innervation of te ECU, EPL EI EDM APL EPB] Median Nerve - Results in "ape hand" - Thumb movements are limited because of the limited ability to oppose and abduct the thumb - High lesion results in decreased wrist flexion as well b/c of denervation of the anterior compartment - Weak function remains because of ulnar half of FDP and the FCU [Supplies 2.5 thenars and 1&2 lumbricals FCR, palmaris longus, and FDS] AIN - Denervation of the FPL - Loss of thumb flexion Ulnar Nerve - Results in a "claw hand" - Hand is drawn laterally because of the imbalance created by the denervation of the FCU - MCP's become hyperextended, and the IP's cannot be extended because of the hood disruption created by muscle imbalances by the lumbricals and the interossei (Thumb: - Abductor pollicis - extend thumb toward you - Adduction - not affected by median nerve; thumb back in - Flexor = cross palm - Extend = bring back - Oppositional - hand like claw -> touch thumb to pinky - Interossei ulnar nerve o Palmar = add o Dorsal = abd - Lumbricals -> ulnar N = 3&4 - - median nerve = 1&2 - Flexor MCP extend ICP)

The Surgical Neck

Region below the greater and lesser tubercles (where the upper margin of the humerus joins the shaft) Axillary nerve and posterior humeral circumflex artery lie in close proximity to the medial aspect of the neck [When fractured can result in a disruption of the axillary nerve distribution...deltoid atrophy Axillary Nerve C5,6 Terminal Branch of the posterior cord 3 posterior Divisions Supplies the GH joint, teres minor and the deltiod. Gives rise to the superior lateral brachial cutaneous then winds around the surgical neck deep to the deltiod Supplies the skinof the posteriolateral arm] Axillary nerve and posterior humeral circumflex artery lie in close proximity to the medial aspect of the neck They pass posterior through the quadrangular space They pass posterior through the quadrangular space Superior Teres Minor Inferior Teres Major Medially Long Head of Triceps Laterally Coracobracbialis Surgical Neck [Borders of the Quadrangular space]

Palmaris Longus

Small fusiform muscle Absent on one or both sides in approximately 14% of the population O: medial epicondyle of the humerus (common flexor origin) I: distal half of the flexor retinaculum and palmar aponeurosis A: flexes hand at the wrist N: median nerve

The Ulna

Stabilizing bone of forearm Medial and longer of the two bones in forearm Larger proximally and narrow, conical shape distally Proximally it has two projections (processes) - Posterior - Olecranon - Anterior - Coronid [Remember the interosseus membrane that joins these bones; Ulna is more firmly connected to the humerus than the humerus is to the ulna; The longer of the 2 forearm bones] - Anterior surface of olecranon process forms the trochlear notch that articulates with the trochlea of the humerus - Inferior to the coronoid is the tuberosity of the ulna - The distal portion of the ulna is the head and the peg-like styloid process. - the ulna styloid does not extend as far distally as the radial styloid. (- Ulna more stable; moves more in true elbow joint; but in forearm movement - radius spins around ulna (pronation and supination) o (pronation = radius crosses; supination = crosses back over) o Watch cadavers - rigor mortis = arms are backwards - Superiorly has hook notch = olecranon process -> olecranon fossa (can't extend beyond point in extension) o Inferior = coronoid process -> coronoid fossa -> can't flex after certain point - Trochlea of humerus to trochlear notch - Smooth surface = radial notch; obviously looking at lateral side - Distal surface = head o Small projection on posterior side = styloid process of ulna (bump on medial aspect of wrist - go down from pinky) - Interosseous membrane - Articular fibrocartilaginous disk -> triangular fibrocartilaginous complex (TFCC) o Gap between ulna and carpal joints o Disk is like sticking gum in their o If bone = can't ab/adduct hands - Radius extends lower than ulna o Allows for more adduction (ulna deviation) than abduction (radial deviation) - Ulna tuberosity below cortanoid process o Brachialis attaches)

Anterior Glenohumeral Ligaments

Superior glenohumeral ligament (SGHL - - Most Engaged when arm by side for external rotation) Middle glenohumeral ligament (MGHL - 2-4 oclock - 45 degrees - Only on anterior side - What checks internal? The body - What checks externally? The MGHL) Inferior glenohumeral ligament (IGHL - 4-8 oclock - Most Engaged when arm at 90 degrees for external rotation - Extends anteriorly and posteriorly o At 90 degrees: o When external rotation = anterior band is checking o Internally rotate = posterior band is checking) Coracohumeral ligament (CH - Coracohumeral ligament - checks when arm is by side/0 degrees of motion; 180 degrees of flexion; 50-60 degrees of extension) [GH ligs form a Z on the anterior capsule and sometimes only exist as capsular thickenings...all portions tighten on lateral rotation of the humerus and anterior glide of the head CH blends with the superior capsule and inserts with Supra tendon on the greater tuberosity Speculation that the CH ligament is somewhat responsible for maintaining joint integrity when the arm is at rest] - Combination of motions for these ligaments - In abduction - ex: has different aspects of internal and external rotation due to degree of abduction No ligament reinforcement on posterior side Also weak inferior because of axillary pouch

Deep posterior muscles: Levator Scapula

Superior third is straplike Lies deep to the sternocleidomastoid in the neck Inferior third is deep to the trapezius Origin: Transverse processes of C1 through C4 Insertion: Superior part of Medial border of Scapula Action: elevates and rotates the scapula as well as tilting (depressing) the glenoid cavity inferiorly Nerve: Dorsal Scapular nerve [Works with the upper trap to elevate; Cervical arcs] [Located just anterior to Splenius Capitis Insertion under upper trap. Note the course of the Spinal Accessory nerve down the belly of levator] (- Elevates scapula (like name suggests) - Never extend below root of spine of scapula - Upper Cervical spine - Attaches at superior angle of medial border of scapula - When contracts, pulls superior angle up, and downwardly rotates the scapula (because only pulling at one corner of triangle - causes rotation not elevation))

Branches of the Brachial Plexus

Supraclavicular : Dorsal Scapular Long Thoracic Nerve to Subclavius Suprascapular Infraclavicular: Medial Pectoral Nerve Medial Cutaneous nerve of arm Medial Cutaneous nerve of the forearm ThoracoDorsal Nerve Lower Subscapular nerve Upper Subscapular Nerve Lateral Pectoral Nerve Axillary Nerve Musculocutaneous Nerve Median Nerve Ulnar Nerve Radial Nerve

The Axilla

The "armpit" Pyramidal space inferior to the GH joint Provides a passageway for vessels and nerves to reach the upper limb Consists of a(n): - Apex: -- Lies between the 1st rib, clavicle and the superior edge of the subscapularis -- Neurovascular structures pass to the axilla through the cervicoaxillary canal - Base -- Formed by the concave skin, subcutaneous tissue and fascia extending from the arm to the thoracic wall - Four walls Anterior Wall - Formed by the pectoralis major, pectoralis minor, and the fascia associated with them Posterior Wall - Formed chiefly by the scapula and the subscapularis anteriorly - Inferiorly, formed by the teres major and latissmus dorsi Lateral Wall (?) - narrow and bony wall - formed by the intertubercular groove in the humerus Medial Wall - Formed by the thoracic wall - first to fourth ribs and intercostal muscles - and the overlying serratus anterior Contents of Axilla - Axillary Artery - Axillary Vein - Lymphatic Vessels - Lymph Nodes - Brachial Plexus (innervates deltoid, teres minor - Break in surgical neck of humerus -> might hit this nerve and/or posterior humeral circumflex artery)

Arterial Supply

The Axillary artery continues as the Brachial artery after it crosses the inferior border of the Teres Major muscle (name changes) the Brachial artery supplies a Profunda Brachial 1/3 the way down the Humeral shaft. Deep artery to the posterior arm At the elbow branches into the Radial artery and Ulnar artery (named for the bone they are nearest) The Ulnar artery also supplies the deeper Anterior and Posterior Interosseous arteries that run along their respective sides of the interosseous membrane Distal to the wrist the Radial and Ulnar arteries participate in two palmar and one dorsal arterial arches that are anastomotic channels between these two arteries (Arterial artery mostly medial - Can get brachial artery pulse - Profunda brachial = deep brachial - Cuboidal fossa = split Flex wrist = feel 1st tendon (medically) - just lateral is brachial artery Thumbs up -> ulnar?? (double-check) Anterior interosseous travels anteriorally; flexors Posterior interosseous - extensors of forearm Artery supplies most of superficial Dorsal has one arch Anastomoses )

The Elbow - Arthrology

The Joint Capsule - Attachments: - Proximal to olecranon, coronoid and radial fossas - Medial and lateral margins of trochlear notch - Distal to annular ligament, the anterior border of the coronoid and the annular ligament [The joints provide mobility for the hand in space by apparent shortening and lengthening of the UE. The capsule completely encloses the joint] The Joint Capsule - Posterior capsule -- Taut in flexion & lax in extension - Anterior capsule: -- Taut in extension & lax in flexion -- Lies close to brachialis [The anterior and posterior capsules are actually thin and weak but the side strengthened by the collaterals] 3 joints within single capsule: - Humero-ulnar - Humero-radial - Proximal radio-ulnar [The capsules attachments to the radius blends with the ligaments of radioulnar articulation] Ligaments - On either side of the joint are two ligaments: the medial and lateral collateral ligaments - Two collateral ligaments keep articular surfaces in contact and prevent side to side movements -- Also named ulnar and radial collateral ligaments [Most hinge joints in the body have collaterals...elbow is no exception...we will use the terms medial and lateral as well as the terms ulnar and radial] The Radial Collateral: Extends from the lateral epicondyle of the humerus and blends distally with the annular ligament of the radius [Note that this is a strong triangular band, offers some protection against varus stresses at the elbow and provides some resistance to distraction because of the blending with the annular ligament] Lateral Ulnar Collateral Ligament - "LCL" - Fibers running from the lateral epicondyle to the ulna Medial Ulnar Collateral Ligament - Medial and triangular shaped - Extends from the medial epicondyle of the humerus to the cornoid process and olecranon of the ulna - Consists of 3 bands: - Anterior- cord-like and strongest - Posterior- fan-like and weakest - Oblique- deepens the socket for the trochlea of the humerus [Anterior is considered the primary stabilizer of the elbow to valgus stress...from ant medial epicondyle to the ulnar coronoid process Post - sometimes blends with the joint capsule...from the post. aspect of the med. epi. to the ulnar coronoid and the and the olecranon Oblique...between the olecranon and the ulnar coronoid...keeps surfaces in approximation]

Myology of the Shoulder and Pectoral Girdle

The Shoulder and Pectoral Region (= glenohumeral joint is most important - Shoulder impingement o Subacromial space o Attached to greater trochanter - Supraspinatous muscle -> supraspinatous tendon (what gets impinged) - 2 types of impingement: o Bad scapulahumeral rhythm (mechanical) o Abnormal shape of acromium (such as hook shaped) (structural) - Upward and downward rotation o Synergy = Abduct and upward rotate (not just individual action) Muscles that move scapula v. muscles that move shoulder)

The Radius

The radius is shorter and more lateral of the two forearm bones Radius and ulna are joined together in part by a tough connective tissue sheet, the interosseous membrane [The more lateral bone in the anatomic position] The proximal head of the radius is concave for articulation with the capitulum Inferior to the head of the radius is the radial tuberosity The radius flares distally and curves both anteriorly and medially There is a notch in the distal flare for articulation with the ulna called the ulnar notch Dorsally the radius has a tubercle that acts as a pulley for forearm muscles Laterally the radial styloid projects from the radius It extends further distally than the ulnar styloid the distal radius articulates with the proximal row of carpal bones at the wrist (- More mobile bone of forarm - Superior = head; articulates with capitulum of humerus = humeralradius joint - Connects via neck - Anterior/medial bump = radial tuberosity

Trunks of the Brachial Plexus

The roots of the plexus unite to form three trunks -Superior -Middle -Inferior C-5 and C-6 root unite to form Superior Trunk C-7 continues as the Middle Trunk C-8 and T-1 unite to form the Inferior Trunk

Cubital Fossa

Triangular hollow area on the anterior aspect of the elbow Boundaries: Superiorly- an imaginary line connecting the medial and lateral epicondyles Medially- pronator teres Laterally- brachioradialis Floor- brachialis and supinator Roof- bicipital aponeurosis Contents: BAM Terminal part of the brachial artery -- Beginning of its branches: radial and ulnar arteries Deep accompanying veins Biceps brachii tendon Median nerve [Contains BAM: the biceps tendon, the brachial artery, the terminal branches and the brachial veins. Median nerve and the radial nerves] Cubital Fossa Terminal part of the brachial artery Beginning of its branches: radial and ulnar arteries [In the cubital fossa the brachial artery divides into the radial and the ulnar arteries] Deep accompanying veins Cephalic Basilic [Median nerve and the radial nerves Deep veins are the cephalic and the basalic...cephalic is located along the surface of the biceps and passes between the delt and the pec to empty into the axillary vein Basalic passes on the medial side of the forearm...basalic becomes the axillary in the axillary space Median nerve has no branches in the axilla or arm...passes deep into the forearm and supplies all of the anterior musculature except 1.5 muscles..articular branches to the elbow]

Scapula (Shoulder Blade)

Triangular shaped flat bone Lies on posterolateral aspect of the thorax Overlies 2-7 ribs Supraspinatus fossa Infraspinatus fossa Spine - Acromion Coracoid - projects anterolaterally from the glenoid cavity and lies superior to it Subscapular fossa Coracoid - projects anterolaterally from the glenoid cavity and lies superior to it Medial border Lateral border Lateral angle Suprascapular notch - Marks superior border of the scapula Glenoid cavity/fossa - scapular end for articulation with the Glenohumeral (GH) joint (- Flat/triangular - Sits on posterior ribs (2-7) - Helps form true shoulder joint - Socket part - Spine of scapula is distinctive feature - originates from medial side and extends laterally and then turns - forms acromion process o Region above: supraspinatus fossa o Below: infraspinatus fossa o Supraspinatus and infraspinatus muscles as part of rotator cuffs? o Subscapular fossa o Coracoid process: extends anteriorally; in front and superior is acromion process o Triangular so 3 borders; named for location (superior, lateral, and medial border) 3 different angles Lateral angle forms glenoid fossa/cavity o At base of coracoid process = suprascapular notch - Glenohumeral joint (GH))

Scapulo-Humeral Rhythm

[Scapula contributes to both flexion and abduction by upwardly rotating the fossa 60 degrees...maintains joint congruity...large ROM with increasing stability that if one joint...maintains good length tension relationships between muscles] (- Ab/adduction on frontal plane anatomically - But functionally is different -> scap - Important part of assessing shoulder; scapula should start at 30 degrees; if does not start until ex: 90 degrees - means humerus digging into already) Ex: lifting arms up (abduction) - Glenoid rotating inferiorly - Scapular accommodating - If head of humerus wants to glide inferiorly o Scapula trying to cup - upward rotation - Downward rotation with adduction Other motion: protraction/retraction - Scapular also protracts (abducts) during upward rotation Other: spin - Posterior spin clavicle - Elevating clavicle laterally; and depression medially (sternum clavicular joint then also moves))

The Carpals

from lateral to medial the proximal row is made up of the scaphoid, lunate, triquetrum and pisiform scaphoid also called the navicular of the hand pisiform is a sesamoid bone in the tendon of flexor carpi ulnaris muscle [Scaphoid is commonly fractured Fall on an outstretched hand Slow healing b/c of poor blood supply] the distal row of carpals articulate with the proximal row of carpals at the mid carpal joint from lateral to medial the distal row of carpals are: Trapezium (articulates with the thumb's metacarpal), Trapezoid, Capitate and Hamate (has a prominent hook) [Curved projection on the palmar surface Forms the radial border for Guyons canal which transports the ulnar nerve and artery to the hand] (- Ulna has small intercalated disk - 8 in # (2 rows of 4 - proximal with radius and distal with ulna) - Scaphoid = most lateral; lunate is next to it; pisiform (small and round; triquetrum under neath - Trapezium (articulates with thumb), trapezoid, capitate, and hamate (hook of the hamate) o With carpals to form carpal-metacarpal joints - Most plane gliding; - 1st metacarpal/carpal joint = biaxial and biplane o Both surfaces have concave and convex shapes)

Pectoralis Major

large and fan shaped covers the superior part of the thorax has clavicular and sternocostal heads sternocostal head is larger sternocostal head forms anterior wall of the axilla forms deltopectoral groove with deltoid where cephalic vein runs Deltopectoral Groove - Depression below the lateral third of the clavicle - Boundaries are the clavicle superiorly, the deltoid laterally, and the pectoralis major medially - Point where the cephalic vein passes deep to join the axillary vein Origin: Medial 1/2 of clavicle (clavicular head) and anterior sternum and superior 6 costal cartilages (sternal head) Insertion: Lateral lip of intertubercular groove Action: Adduction and medial rotation of shoulder Nerve: lateral and medial pectoral nerves [Medial and Lateral Pectoral Nerves come off the medial and lateral cords of the plexus] (- Fan shaped: large origin, small insertion - Adduct, internal rotate shoulder (goes to lateral lip), less flexion - Deltoid-pectoral groove (landmark): contains vein from upper extremity to heart o cephalic vein o S: clavicle; L: deltoid M: pectoralis major - Medial and lateral pectoral nerves (branches of brachial plexus))

Pectoralis Minor

lies in the anterior wall of the axilla largely covered by pectoralis major triangular in shape with the coracoid process, forms a "bridge" under which vessels and nerves pass Origin: 3rd to 5th ribs(medial portion) Insertion: Coracoid process Action: Scapular protraction and depression Nerve: Medial Pectoral nerve [Medial pectoral nerve from the medial cord] [Course of the medial pectoral nerve involves joining with the communicating branch from the lateral pectoral nerve and then continuing to innervate the pec minor. Pierces the minor and then continues on to innervate the major.] (- Attached to coracoid; when contract: depression and protraction; pushes scapula forward - Medial pectoral nerves)

radius notes

o Biceps attaches o Body naturally in supination o During pronation - biceps need to contract to pull back radius that has been turned medially and posteriorly o Biceps = strongest supinator? o (not the same case for ulna because it doesn't move) - All elbow flexors: Brachioradialis = flex elbow; radialtuberosity (also supinator); brachialis (not affected by supination/pronation) - If lifting weights in supination - mostly biceps; in pronation - mostly brachialis; drinking beer = brachioradialis o Actions really different)

Serratus Anterior

overlies lateral part of the thorax forms medial wall of the axilla named because of the saw-toothed appearance of its fleshy slips used when punching or reaching anteriorly some refer to as "boxer's muscle" Origin: External surfaces of lateral parts of ribs 1 through 8 Insertion: Anterior surface of medial border of scapula Action: Scapular protraction Nerve: Long Thoracic nerve [Long Thoracic Nerve from the C 567 Nerve roots Supraclavicular] (- During contraction (abduction), scapula protracts o Part of synergy for upward rotation - Prominent medial border of scapula (weak muscle in a lot of people) o Scapula sticks out like wings "winging of scapula" - Long thoracic nerve (nerve comes out at neck and travels laterally in the thoracic) - Boxer's muscle)