Final answer:
The rotator cuff is located around the shoulder joint, consisting of four muscles—supraspinatus, infraspinatus, teres minor, and subscapularis. It provides primary support to the joint by stabilizing the humeral head in the glenoid cavity and enables various upper limb movements.
Step-by-step explanation:
The rotator cuff is a group of muscles and their tendons that surround the shoulder joint. These muscles include the supraspinatus, infraspinatus, teres minor, and subscapularis, all of which arise from the scapula and attach to the greater or lesser tubercles of the humerus. The tendons of these muscles fuse with the anterior, superior, and posterior walls of the shoulder joint's articular capsule, forming a strong connective tissue structure around the humeral head. This structure is critical because it provides primary support for the glenohumeral joint, serving as "dynamic ligaments" that adapt their contraction strength to stabilize the shoulder and hold the head of the humerus in the glenoid cavity.
Additionally, this muscular cuff is involved in various movements of the upper limb and plays a role in preventing injuries such as those seen in baseball pitchers who may experience pinched, inflamed, or torn rotator cuff tendons due to repetitive overhead throwing motions.