The 4 of scapulohumeral muscles, viz. supraspinatus infraspinatus, teres minor, and subscapularis (frequently called SITS muscles) are termed rotator cuff muscles for they form musculotendinous/rotator cuff around the glenohumeral joint.

Tendon of supraspinatus fuse superiorly, tendons of infraspinatus and teres minor fuse posteriorly, and that of subscapularis fuse anteriorly. This cuff has a significant role in stabilizing the shoulder joint.

The primary function of rotator cuff muscles is to grasp the relatively large head of humerus and hold it against the smaller, shallow glenoid cavity.