CM2 2 shoulder disorders

____ has greater mobility than any other joint

shoulder

3 bones of shoulder girdle

clavicle

scapula

proximal umerus

4 articular surfaces of shoulder girdle

1. sternoclavicular

2. acromioclavicular

3. glenohumeral

4. scapulothoracic

principal articulation of shoulder

glenohumeral joint

“shoulder joint”

scapulothoracic “joint”

NOT a true synovial joint

scapulothoracic articulation is formed by

convex surface of posterior thoracic cage and concave surface of anterior scapula

has gliding surface formed by subscapularis and serratus anterior muscles

labrum

deepens the glenoid fossa to hold the head of humerus in place

serves as attachment for long head of biceps muscle

rotator cuff role

stabilizes the humeral head within the concavity of the glenoid (with labrum)

rotator cuff function

shoulder to rotate internal and externally

flexion

pec major role

adduct arm

supraspinatus muscle arises from

posterior surface of scapula above scapular sign

supraspinatus muscle attaches to

greater tuberosity

supraspinatus muscle function

flexion and abduction

infraspinatus location

infraspinatus fossa on posterior surface of scapula

teres minor

occupies upper 2/3 of axillary border of scapula

tendons of what attaches to greater tuberosity of humerus

infraspinatus

teres minor

infraspinatus and teres minor function

external rotation

subscapularis location

subscapular fossa on ANTERIOR surface of scapula

subscapularis insertion

lesser tuberosity

subscapularis function

internal rotator of shoulder

Rotator Cuff Impingement

Tendons of rotator cuff are squeezed between humerus and acromion

rotator cuff impingement leads to

rotator cuff tendonitis

subacromial bursitis

rotator cuff tendonitis

repetitive overhead use of arms -> strain

Rotator cuff tear

injury tears rotator cuff tendon that’s been weakened by age or wear/tear

rotator cuff tear sx

weakness in arm + pain

Frozen shoulder (adhesive capsulitis)

Humerus adheres to scapula and glenoid -> shoulder pain and stiffness

Frozen shoulder (adhesive capsulitis) occurrence

prolonged fixation or disuse

Frozen shoulder (adhesive capsulitis) resolution of sx

Sx resolved with time and therapy, or released under anesthesia