The shoulder complex

shoulder gurdle: sternum, clavical scapula

4 articulations: sternoclavicular, acromioclavicular. coraclavicular (held by CC ligaments), scapulothoracic (held by muscles)

Sternoclavicular Articulation: ligament support: anterior sternoclavicular ligament, posterior

Scapulohumeral rhythm: every bit of humeral movement gets a scapular movement, so we can make about 30 deg of humeral movement until we get scapular movement and then it is every 2 deg of shoulder movement, the scapula rotates 1 deg, so it is a 2:1 ratio

Glenohumeral articulation: articulation of humerus and glenoid fossa, designed for mobility ( most mobile in the body) lacks bony and ligament support, shallow glenoid fossa

Sublaxation- partial, goes out and comes back in

Dislocation- comes out and stays out

Passive, static stabilizers: articular surface, gelnoid labrum, joing

Anterior Deltoid:abduction, flextion, horizonal adduction, internal rotation

Shoulder abduction joint action- the shoulder girdle upward rotaiton

shoulder adduction- girdle downward rotation

shoulder flexion- the girldle upward rotation and elevation

shoulder extension- depression and downward rotation of the girdle

shoulder internal rotation- protraction of the girdle

shoulder external rotation- retraction of the girdle

shoulder horizontal adduction- protraction of the girdle

shoulder horizontal abduction- retraction of the girdle