I and several friend have back problems, mine is spondyloarthropy, ten dollar word for arthritis of the spine. Doctors say I will be in a wheel chair before long, I say I am not complying with her prediction. I use a TENS Unit for pain control. Several of my friends use TENS Units. Before useing a TENS Unit find out if it is contraindicated for you because of pregency, pacemaker, metal implants, etc.