Numberonewendy,

I have something very similar to the machine you guys are talking about (mine is one big machine). Anyway, I also have lower back problems, and I didn't really find it to hurt my back. I do exercises to strengthen my lower back anyway, so that could be why I didn't run into any problems, but who knows. You can feel it working that area too, as well as arms and tummy. The problem I have with the thing is that it kills my wrists...there is definitely a thread out there about the ab roller - tons a positive comments were made about it.

GoodLuck,
E