Various treatments for back pain have been developed over the years; some are effective, but most give minimal relief if they give relief at all. One treatment modality being bandied about is electrotherapy – the use of electricity along nerve pathways to block pain. There are two methods of electrotherapy – TENS and electro-acupuncture. What is TENS? TENS is the acronym for transcutaneous electrical nerve stimulation; the therapy sends electrical pulses along nerve pathways to stimulate the nerves and block pain. The unit is connected to the skin via electrodes, and the TENS unit sends impulses at a specified width, frequency, and intensity. TENS pulses can be high frequency and low intensity (no motor contractions) or low frequency and high intensity (causes motor contractions). Uses for TENS TENS has been used effectively in physical therapy, to relieve muscle spasms. At low frequency and high intensity, the TENS unit contracts muscles; for patients with severe spasms, the therapy