A Modification of the Active Compression Test for the Shoulder Biceps-Labrum Complex

The active compression test (O'Brien Sign) is widely used by physicians to aid in the diagnosis of biceps-labrum complex disease. This maneuver has been particularly criticized in the literature, however, with regard to interobserver reliability. Criticisms may in fact stem from inaccurate and inconsistent practice of the examination maneuver, stemming from both patient- and physician-related errors. In this Technical Note, we introduce an easy modification to the O'Brien Sign that limits such errors and improves test uniformity.