A TENS Unit is wonderful. It consists of a small (size of a deck of cards) 9V battery operated unit w 4 sticky electrodes that you place over sore spots for from 20 min up to 12 hours on and 12 hours off. The strong tingling (NEVER PAIN) reduces inflammation which causes pain and speeds healing. I got mine in 2010 for wrist problems and when they were OK started putting it on my lower back. Sacrum and sore muscles at the sides. NEVER directly on the spine or across the skull! It comes with a book. I got mine for under $20 at http://www.tenspros.com - the #3000. You don't need anything more elaborate that than. I'd order extra electrodes to save on later S&H. I sent one to each of my brothers who have bad backs. One bro had shoulder surgery. The PT used one on him. He said he had one at home & was told to USE it.