Many golfers try to make a complete backswing based on how far their hands and arms go back. In reality, your backswing is completed when your shoulders have made a full turn. Turn hands, arms and shoulders together on the backswing. Once your shoulders have finished turning, trying to make the hands and arms go any further may cause them to veer off plane. Don't get caught up in completing the swing with your hands. Regardless of how far the hands and arms get, when the shoulders are done turning, the backswing is finished.