harpyquilter,
I purchased a "drafting" chair that I use in front of my short arm. It has a metal ring about half way between the seat and the floor for your feet. The seat is level with my backside if I am standing next to it. So I kind of step up to sit down. That way, my knees are above the lower rails. And because I put some floating wood floor strips over my carpet, I can slide the chair with one foot. I never start quilting on the same day as I load the quilt. My back just won't take it either. Hope this helps.