Rotator Cuff Impingement

The rotator cuff can get "pinched" between the humeral head and acromion when the arm is raised to the side.

The infraspinatus and teres minor rotate the forearm away from the body or in the hand-waving position (external rotation), and the subscapularis rotates the forearm towards the body (internal rotation). Once the balance between motion and joint stability is altered through weakness in the static structures (ligaments) or the dynamic structures (rotator cuff muscles), pain and impaired function will invariably ensue.1

Baseball pitching, quarterbacks, tennis players (serving), and swimmers are prone to rotator cuff tendonitis and impingement syndrome because they perform a lot of overhead movements. The rotator cuff is most vulnerable in this position.

Impingement syndrome occurs when the rotator cuff tendon becomes pinched between the humeral head, on which it is attached, and the overhanging acromion process, when the arm is raised above the head.

This happens when the space becomes narrowed, as occurs when the rotator cuff muscles weaken and the humeral head rides high in the socket or when bone spurs and calcium deposits narrow the space. Impingement also occurs when the contents of the subacromial space increase in size, most often due to a swollen rotator cuff tendon or bursa, which is painfully squeezed between the humeral head and the acromion process. MRI (Magnetic Resonance Imaging), which is an expensive test to look at the rotator cuff, often does not help in evaluation and management.

Common treatment for rotator cuff tendonitis and impingement syndrome includes rest, non-steroidal anti-inflammatory drugs (NSAIDs), physical therapy, and cortisone injections into the subacromial space. Because a cortisone injection has very strong anti-inflammatory properties, it may reduce the swelling in the tendon and bursa, relieving the symptoms. These treatments may temporarily help, but since the underlying cause has not been addressed the problem invariably returns.

Degenerative fraying and tearing of the tendon may occur if constant irritation of the tendon occurs from the impingement process over time.

What About Shoulder Surgery?

When the usual non-operative methods of treatment, including rest, medications, cortisone injections, physical therapy, and home exercises, are attempted but fail to correct the problem, surgery is often suggested. Surgery has its downside that an athlete must always remember: surgery does not always achieve the desired results or return the athlete to the previous level of performance.

1. DeLisa, J., ed. Rehabilitation Medicine: Principles and Practice. Third Edition. Philadelphia, PA: Lippincott-Raven Publishers, 1998, pp. 1612-1614
2. Matsen, F. "Shoulder overview." Feb 1997. http://www.orthop.washington.edu/bonejoint/zrzzzzxz1_2.html. 09/14/98.

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