What is the method used in the AC Crossover test?

The AC Crossover test is designed to assess for acromioclavicular joint pathology. In this test, the patient flexes the shoulder to 90 degrees and adducts the arm across the body. This movement places stress on the acromioclavicular joint and can elicit pain if there is an injury or degeneration present in that area.

During the test, the position of the shoulder and the movement being performed allows for evaluation of the integrity of the AC joint, as well as the potential involvement of surrounding structures, such as the surrounding muscles and ligaments. Pain experienced during this maneuver is indicative of possible AC joint dysfunction or injury.

The other options provided describe movements or assessments that are not relevant to the AC Crossover test. For instance, pushing on the medial border of the scapula is more appropriate for assessing scapular stability, applying a valgus stress on the elbow pertains to testing ulnar collateral ligament integrity, and flexing the arm while monitoring pulse wouldn't provide useful information related to the acromioclavicular joint. Thus, the method most accurately reflecting the AC Crossover test is indeed flexing the shoulder to 90 degrees and adducting across the body.