I ordered one of these for myself several years ago..... I have trouble with my back from time to time. And at THAT time, I was having alot of trouble with one of my legs. Had lots of trouble going to sleep because of leg aching and moving..... Tried lots of creams for that, didn't help much. I LOVE this machine. It took few nights for my leg to stop aching, but, this helped so much. And for my back, well, it IS wonderful...... I have had other products in the past to help with back aches and such, but nothing works like this. I ordered these for my three grown children over the last two Christmas' and they all love them!!!! MY last child will get one THIS Christmas......Wonderful product......