The Rotator Cuff (RC) is made up of 4 distinct muscles and their tendons, which give strength and stability during motion to the shoulder complex. They are also referred to as the SITS muscle, with reference to the first letter of their names (Supraspinatus, Infraspinatus,Teres minor, and Subscapularis, respectively). The muscles arise from the scapula and hook up with the top of the humerus, forming a cuff round the glenohumeral (GH) joint.