I was using the ab circle when the knee pad slipped and I landed on my knee. causing it to swell severly, it was intense pain. It has been several days and I will be going to the ER today because it hasn't gotten any better. It was the single most painful thing I have ever experienced in my life. When I called to complain to the AB Circle, they informed me they had never heard of anything like that happening, but that they would send me new pads with adhesive on the back, as well as new rollers. I find it hard to believe if there are no... read full review »