Anatomy of the Shoulder

The two main bones of the shoulder are the humerus and the scapula (shoulder blade).

The joint cavity is cushioned by articular cartilage covering the head of the humerus and face of the glenoid. The scapula extends up and around the shoulder joint at the rear to form a roof called the acromion, and around the shoulder joint at the front to form the coracoid process.

The end of the scapula, called the glenoid, meets the head of the humerus to form a glenohumeral cavity that acts as a flexible ball-and-socket joint.

The joint is stabilized by a ring of fibrous cartilage surrounding the glenoid called the labrum.