In this video, the action of controlled lowering of the weight is an eccentric muscle contraction. This motion at the shoulder or glenohumeral joint is internal rotation. Internal rotation is demonstrated starting with the elbow bent to 90⁰ of flexion and the arm out to the side in 90⁰ of glenohumeral abduction. The motion consists of the weight being slowly lowered into internal rotation at the shoulder as seen from a lateral view.