The rotator cuff is a group of four muscles and several tendons that surround each shoulder joint. These muscles and tendons work together to hold your shoulder joints in place while allowing you to lift and move your arms.
Most cases of shoulder pain are caused by a rotator cuff injury or rotator cuff disease. These conditions are often the result of trauma, such as falling onto the arm or shoulder in pain, which may cause a muscular tear of the rotator cuff or a subacromial impingement. Another common rotator cuff disorder is calcific tendonitis, which may be caused or aggravated by overuse due to a frequent repetitive movement during a sport or professional task.