Glenohumeral Joint (Shoulder Joint)

The **shoulder joint** is a ball-and-socket joint formed by the articulation of the humeral head with the glenoid cavity of the scapula. This joint offers the greatest range of motion in the body. However, this high mobility comes at the cost of structural stability, as the joint’s flexibility is due to limited structural support. The extensive range of motion is made possible by the articulation of the large, rounded humeral head with the smaller, shallow glenoid cavity. The articular capsule surrounding the glenohumeral joint is relatively thin and loose, allowing significant movement of the upper limb. Some structural support is provided by thickenings in the articular capsule wall, which form weak intrinsic ligaments, strengthening the superior and anterior portions of the capsule. However, the primary support for the shoulder joint comes from muscles that cross the joint, especially the four rotator cuff muscles. These muscles (supraspinatus, infraspinatus, teres minor and subscapularis) originate from the scapula and attach to the greater or lesser tubercles of the humerus. The fusion of the tendons of these four muscles creates a thickening of the capsule known as the rotator cuff. *LICENSES AND ATTRIBUTIONS CC licensed content, Shared previously Chapter 9. Authored by: OpenStax College. License: CC BY: Attribution. License Terms: Download for free at: http://cnx.org/contents/R3D4RG6w@4/Anatomy-of-Selected-Synovial-J.*