The acromioclavicular shear test, also known as the AC shear test, is a physical examination maneuver used to diagnose injuries to the acromioclavicular (AC) joint, which connects the collarbone (clavicle) to the shoulder blade (acromion). The test involves applying a downward force to the top of the shoulder while stabilizing the collarbone, and observing for any excessive movement or pain. A positive test, indicating an AC joint injury, can help differentiate between AC joint sprains and more severe separations.
