What is the rotator cuff and what does it do?
The rotator cuff is a large tendon comprised of four muscles which combine to form a “cuff” over the upper end of the arm, the head of the humerus. The four muscles—supraspinatus, infraspinatus, subscapularis and teres minor—originate from the “wing bone,” the scapula, and together form a single tendon unit that inserts on the greater tuberosity of the humerus. The rotator cuff helps to lift and rotate the arm and to stabilize the ball of the shoulder within the joint.
