squats hurt my back - not anymore!

Thanks for the suggestions a few weeks ago about better squat form to
prevent the strain in my upper back. So I've taken to taking off my
shoes while squatting and pushing with my heels instead of the balls
of my feet. My weight must have been too far forward. I can't lift as
much, because I'm working on the balance more to keep myself from
falling backwards, but that's okay with me. My upper back doesn't hurt
anymore after doing them, or at least not much, and that's what i was
hoping for.

Dave