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What is the quadrilateral space syndrome (QSS)? My older brother is a javelin thrower in track and field events. Now he can't compete because of this QSS problem.

Quadrilateral space syndrome is a rare but potentially disabling condition affecting overhead athletes most often. Swimmers, pitchers, and gymnasts are at risk for QSS. Evidently, so are javelin throwers.

In QSS, fibrous adhesions form around one of the nerves in the shoulder. The specific nerve affected is the axillary nerve. This nerve comes off a group of nerves in the neck and shoulder called the brachial plexus. The axillary nerve branches off right at the armpit.

Then it travels through the quadrangular space with an artery and vein in the same area. The quadrilateral space is formed by muscles on the top and bottom and along the inside of the space. The outer edge of this space is formed by the neck of the humerus (upper arm bone).

When adhesions form around a nerve, the nerve can no longer slide and glide inside its tunnel during movement. The scar tissue pulls, pinches, and compresses the nerve. Pain occurs at rest and is made worse with overhead movements.

There is treatment for this problem. A physical therapist can help break up the adhesions and restore the natural movement of the nerve inside its sheath (outer covering). This can be done in one to four sessions for most patients.

If this treatment doesn't work, then surgery may be needed. The surgeon moves the muscles away from the nerve and then releases the adhesions from along the entire length of the nerve. Care is needed to avoid damaging the nerve or nearby blood vessels.

With successful treatment, overhead athletes can return to full participation in their chosen sports activity.

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