O’Brien’s (active compression) test

A clinical test for shoulder injuries.  It was primarily developed to test for AC joint injuries (the joint connecting the collar bone to the shoulder), however it may also test for labral tears of the shoulder.  The test is performed by the examiner bringing the patient’s straight arm across the chest and turning the hand as if pouring out a can of pop.  The examiner then asks the patient to hold that position as the examiner attempts to push the hand and arm toward the ground. A positive finding is demonstrated by pain reported at the top of the AC joint with this maneuver, but not if the hand is supinated.