Shoulder Joint

Description

The shoulder joint (glenohumeral joint) is a ball-and-socket synovial joint formed by the humeral head and glenoid fossa of the scapula. It's the most mobile joint in the body, allowing flexion, extension, abduction, adduction, rotation, and circumduction. The joint sacrifices stability for mobility, with the glenoid labrum deepening the shallow socket. Four rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) provide dynamic stability. The joint capsule is loose and reinforced by glenohumeral ligaments. The long head of biceps tendon passes through the joint. Common injuries include dislocations, rotator cuff tears, and impingement syndrome due to its inherent instability.