Need to know if anyone else has a tens units or have experience using one. My PT thinks I should get one for rehab. I have found a few good ones but a guy at the gym said he has one with a Russian setting and it helps with hard to work / reach muscles. Anyone got suggestions? Now I do know that these things are not like the infomercials and you don't get something for nothing. Just want to know if there is a use for getting one with a Russian setting for use to build muscle along with training.