Behind-the-neck presses or pulldowns demand a large degree of shoulder external rotation and good thoracic mobility something most people don’t have. When you force this range under load, the shoulder joint (glenohumeral joint) goes into an unstable position. The rotator cuff and scapular stabilizers are placed under excessive tension, and the subacromial space becomes compressed leading to impingement and long-term wear. Biomechanically, there’s no additional muscle activation in these variatio