Years ago when I was relatively healthy and exercising, I hurt my back (pulled a muscle?), reaching across while cleaning the bath tub and again while mopping the floor. I read somewhere that if you hurt your back, it could be because your stomach muscles are weak [not including true back disc, etc pain where you need to see a doctor] ( I was practically incapacitated and couldn’t move without hurting). Weak stomach muscles, yeah right, I thought. But a few days later when my back wasn’t hurting very much, I started doing sit-ups/crunches and continued. It also helped the back of an acquaintance of mine who had tried everything, even those ball chairs. So now when my back starts to get a little twingey, I start to do my stomach crunches (watch that you don’t pull on your neck). It really did work for me, along with being conscious of how I was cleaning! And it was free with no adverse side effects.