Ok to lower head in backswing?

It seems natural for me to lower my head a bit in my backswing, especially as my lead knee starts to bend. If I try to eliminate it with a lower setup, then I feel cramped. I'm not swaying, just lowering a couple inches. Is this ok or should I work on eliminating the move, which isn't deliberate just a natural move for me. Thanks, - dennis 13 hcp