Rotator cuff

A group of four tendons that stabilize the shoulder joint. Each of these tendons attaches to a muscle that moves the shoulder in a specific direction. The four muscles whose tendons form the rotator cuff are the subscapularis muscle, which moves the arm by turning it inward (internal rotation); the supraspinatus muscle, which is responsible for elevating the arm and moving it away from the body; the infraspinatus muscle, which assists the lifting of the arm during outward turning (external rotation) of the arm; and the teres minor muscle, which also helps in the outward turning (external rotation) of the arm. Damage to the rotator cuff is one of the most common causes of shoulder pain.