Well Go Low, I think most of us have a problem with moving the hips in a way that support the arm swing or shoulder rotation. I am sure my hips don't generally open up enough in the downswing to put me in a good impact position. It is why I think I hit behind the ball so much. Nothing that I do with my arms or shoulders seems to help the problem with my hips. I think that is why some people think about starting the swing with the lower body. Maybe it is a way of giving the hips a head start until the arms and shoulder turn takes over. Another thought is that I don't get my shoulders completely turned in the back swing and therefore don't give my hips the time they need to get turned.