A TENS unit at my Chiro took a lot of fire out of my knees but the electrodes were put directly on them. I don't have any proof that something on my calf could help in the Lumbar. This company may be profitable enough by the numbars of people willing to try anything. I would probably try the stick-on model (forget the name) that Shack advertises as it will stick on wherever. If anyone tries it out, I am sure they would post their rating of effectiveness to the rest of us. Good Luck, Ken in Texas.