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Rotator Cuff Injuries

  • Definition

    The shoulder bones are held together by a group of muscles that are called the rotator cuff muscles. These muscles are responsible for the shoulder's fine movements, such as throwing a ball.

    Because of the shoulder's shallow socket and lack of ligaments, any weakness of the small rotator cuff muscles makes it easy for the head of the shoulder to slide part way out of the socket, which is a partial dislocation, or subluxation. Or it may slide all the way out, which is a full dislocation.


    The shoulder is a unique joint and is prone to a great many injuries. It is a very shallow ball-and-joint socket. The ball can slide very easily out, which means that the joint is not very stable.

    The rest of the shoulder socket is formed by ligaments that connect various parts of the bony components of the socket and cartilage around the small rim of the bony socket. The shoulder is the only joint in the body that is not truly held together by ligaments. The few ligaments in the shoulder serve only to keep the shoulder from moving too far in any one direction. The ligaments have little to do with holding the joint in place.

    The shoulder socket contains three tendons: the tendons of the long and short heads of the biceps muscle, and the supraspinatus tendon. The biceps tendons connect the biceps muscle to the bones of the shoulder and help the biceps flex the forearm. The supraspinatus tendon connects the supraspinatus muscle and the bone of the shoulder, and aids the supraspinatus to move the humerus, the bone between the shoulder and the elbow.

    Sports in which you bring your arm up over your head, such as baseball, tennis, volleyball, and swimming, are the main contributors to overuse injuries of the shoulder. The rotator cuff muscles are not meant to function under stress with the arm above a line parallel to the ground. If the shoulder joint is continually stressed with the arm in this overhead position, the rotator cuff muscles begin to stretch out. This allows the head of the joint to become loose within the shoulder socket.

    If the head of the shoulder is loose, when you extend your arm backward over the shoulder the head will slide forward, catching the tendon of the short head of the biceps between the ball and the socket. The same thing happens if you raise your arm to the side above a line parallel to the ground. The head will drop in the socket, and the tendon of the long head of the biceps will become impinged. The supraspinatus muscle may also be impinged. This impingement causes the tendons to become inflamed and painful. This is experienced by baseball pitchers and tennis players. Athletes such as free-style and butterfly swimmers who feel pain deep in the shoulder are impinging the supraspinatus muscle.


    Many doctors overlook the true problem with a shoulder impingement. They treat the tendinitis (inflamed tendons) with anti-inflammatory agents or cortisone (steroid) injections. But the anti-inflammatories soon wear off, and the next time the individual throws a ball, the tendon is pinched or impinged again. The pain returns, requiring another injection of more anti-inflammatories.

    The preferable way to treat a shoulder impingement is through an exercise program to strengthen the rotator cuff muscles sufficiently so that the head of the shoulder is held firmly in place and will not slip out of the socket. With no slipping, the tendons will no longer be inflamed or irritated.

    You can restrengthen your rotator cuff muscles initially at home with a free-weight program. Using 15 pounds as the absolute maximum weight, you should do the exercises until fatigue sets in or for 50 repetitions once a day. Your doctor may prescribe physical therapy, in which case a physical therapist can design an exercise program for you. Three out of four rotator cuff problems can be cured with simple exercises.

    Rotator Cuff Tears

    In the past, a torn rotator cuff often resulted in permanent disability. Now, tearing the rotator cuff muscles is not as serious in consequences due to improved rehabilitation programs and better surgical technique.

    A torn rotator cuff is initially treated in the same manner as a stretched one by means of a rehabilitation program. Many tears will heal without surgery. Since the surgery is difficult, it should be avoided unless absolutely necessary. Surgery should only be considered if rehabilitation fails.

    If the tear is not large, a simple surgery through a lighted tube (arthroscope) may be possible. Arthroscopic surgery, which has proved so successful in knee treatment, is now used in treatment of the shoulder. Repairing the rotator cuff muscles through the arthroscope offers a less invasive way to treat injuries.

    A potential problem with rotator cuff tears develops during the recovery period. When the shoulder is rested, as is necessary for 4 to 6 weeks following surgery, the shoulder loses its ability to move properly. This can result in a partially frozen shoulder with limited motion. This necessitates a carefully constructed rehabilitation program, with a long and painful process of restoring the full range of motion.


    Do you recommend anti-inflammatory drugs?

    Will these drugs be taken over a long period of time?

    What are the risks and side effects of the drugs?

    What do you suggest to minimize strain on the muscles?

    Will exercises help?

    What kind of exercises do you recommend?

    Is a referral to a physical therapist called for?

    When can normal activities be resumed?