Glenohumeral Joint (Left)

Description

The glenohumeral joint is a synovial joint formed between the scapula, particularly the glenoid process, and the head of the humerus. It is a ball-and-socket joint, a synovial joint that permits a wide range of movement. The head of the humerus, which forms the ‘ball’ entity of the joint, and the glenoid fossa, which forms the ‘socket’ entity of the joint, are covered in hyaline cartilage. The shallow glenoid fossa is further depended by a fibrocartilaginous ring, the glenoid labrum. The glenohumeral joint is surrounded by a fibrous joint capsule. The capsule is lined by a synovial membrane; strengthened superoanteriorly by the glenohumeral ligaments. The joint is strengthened further rotator cuff muscles (i.e., supraspinatus superiorly, infraspinatus and teres minor posteriorly, and subscapularis anteriorly) and the tendon of the long head of triceps brachii inferiorly.

The glenohumeral joint is the most freely moving joint in the body, due to the large size of the femoral head in comparison to the glenoid fossa and as a result from its slack articular capsule. Movements at the glenohumeral joint occur around three axes, including flexion-extension, abduction-adduction, and medial and lateral rotation of the humerus. A combination of these movements results in circumduction at the glenohumeral joint.