Occult instability is recognized as a major cause of shoulder dysfunct
ion in throwing athletes. Few studies have characterized the findings
of occult instability in nonthrowers. The purpose of this study was to
examine shoulder instability in a group of weight lifters. The sympto
ms, physical findings, and results of treatment for 23 shoulders in 20
athletes are presented. All athletes presented with a complaint of pr
ogressive inability to perform exercises with the upper extremity in t
he abducted, externally rotated position (the ''at-risk'' position) be
cause of pain. One hundred percent of the athletes experienced posteri
or shoulder pain when the shoulder was placed in forced abduction and
external rotation. Thirteen shoulders in 10 patients responded to cons
ervative management including aggressive rehabilitation and modificati
on of technique to avoid the at-risk position. The other 10 shoulders,
which did not respond to conservative treatment, required surgical tr
eatment to alleviate the symptoms. All 20 patients have successfully r
eturned to their previous weight lifting activities.