The rotator cuff is a group of muscles and tendons that surround the shoulder joint, stabilizing it and allowing for a wide range of movement. It consists of four main muscles: the supraspinatus, infraspinatus, teres minor, and subscapularis. Injuries to the rotator cuff can cause pain, weakness, and reduced range of motion.

The tendons at the ends of the rotator cuff muscles can become torn, leading to pain and restricted movement of the arm. A torn rotator cuff can occur following trauma to the shoulder or it can occur through the "wear and tear" on tendons.

Rotator cuff injuries are commonly associated with motions that require repeated overhead motions or forceful pulling motions

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