Shoulder impingement syndrome
What is it?
Shoulder impingement syndrome is caused by pinching of the supraspinatus tendon (part of the rotator cuff) and bursa (lubricating sac) between the upper arm bone (humerus) and the acromion, which is part of the scapula (shoulder blade) and forms the roof of the shoulder. The bursa functions as a cushion to prevent the acromion and the rotator cuff tendons from grinding against each other.
Symptoms
Symptoms include pain, weakness and loss of motion around the shoulder joint, and pain at night when sleeping on the affected side. Pain can often be brought on by lifting and rotating the arm. People sometimes describe a sharp pain brought on by reaching into their back pocket.
Causes
Insufficient room between the acromion and the rotator cuff can cause impingement. Normally, the rotator cuff tendons can easily slide under the acromion each time your arm is raised; however, it is normal to have some degree of rubbing or pinching of the tendons and bursa. Overuse of the shoulder in an elevated position can cause the impingement to become a problem and can lead to ongoing pain or damage to the rotator cuff tendons.
Treatment
Rest, ice, anti-inflammatory medicines and physical therapy are the mainstay of treatment. Corticosteroid injections or surgery may be needed in severe cases.
Last Reviewed: 02 September 2009
- 1. McMahon PJ, Kaplan LD. Sports medicine. In Skinner HB, ed. Current diagnosis & treatment in orthopaedics. 4e. New York: McGraw-Hill. Available from: http://www.accessmedicine.com/resourceTOC.aspx?resourceID=20 (accessed Nov 2009).
