Kinematic changes have been thought to be present in people with symptoms of impingement and to result in further decreases in the available supraspinatus muscleoutlet or suprahumeral space.15,17–19 Motions that bring the greater tuberosity in closer contact with the cora- coacromial arch20 are particularly problematic. These motions include excessive superior or anterior translations of the humeral head on the glenoid fossa, inadequate lateral (external) rotation of the humerus, and decreases in the normal scapular upward rotation and posterior tipping on the thorax, all occurring during humeral elevation. These kinematic changes have all been purported to occur in patients with symptoms of impingement.