An anatomic evaluation of the active compression test.

The goal of this study was to describe the anatomic relationships present during the active compression test. Four pairs of cadaveric shoulders were positioned to simulate the active compression test. The shoulders were embedded in polyurethane and evaluated in the axial and coronal planes with a planer. In the axial plane, all internally rotated shoulders demonstrated contact between the lesser tuberosity and subscapularis tendon and the superior aspect of the glenoid and labrum. In the externally rotated position, there was no contact between the superior structures of the shoulder. In the coronal plane, the internally rotated specimens revealed contact between the supraspinatus tendon and the lateral aspect of the acromion. There was no contact between the supraspinatus tendon and the acromion when the shoulders were externally rotated in the coronal plane. The results demonstrate that the active compression test can be used to assist in the diagnosis of superior labrum anterior-posterior lesions as well as other shoulder pathology.