I have been using my left foot for sewing for the past 8 years. The teacher we had at the time told us about it then Alex Anderson had a chiropractor on Simply Quilts. She said the same thing, it's good for your back. I know when I first starting doing it, it felt strange but after a couple of weeks my back did feel better. It is just second nature to me now and I know I can sit longer than I could when I sewed with my right foot.