Electrodes device on shoulder, transcutaneous interferential el?>
Ask the Experts

Do TENS Devices Relieve Pain?

by Jeanine Barone  

Q: Can using a TENS device help relieve pain, such as backaches?

A: Though the evidence is unclear, it may be worth a try for acute or chronic pain. Transcutaneous electrical nerve stimulation, or TENS, delivers pulsed electricity through electrodes attached to the skin via adhesive pads, resulting in a “tingling” sensation at or near the painful site. The mechanism is not entirely clear, but TENS may interfere with the transmission of pain signals via nerve fibers of the spinal cord or affect neurotransmitters that mediate pain. Many physical therapists administer TENS in their offices, but you can purchase small, inexpensive, battery-powered devices online or in many drugstores for self-administered treatment.

TENS is a conservative, nondrug treatment that may help relieve various types of pain, according to some, but not all, studies. A review by the Cochrane Collaboration evaluating TENS for acute pain (for instance, caused by rib fractures or medical procedures) included 19 studies and concluded that there is “tentative evidence” that it can reduce pain intensity compared to a placebo (usually a TENS device delivering little or no current). But it noted that many of the studies were small and had methodological problems, such as inadequate “blinding” as to whether the real or sham treatment was being given.

An earlier meta-analysis that pooled data from 38 studies concluded that TENS is effective for chronic musculoskeletal pain, compared to a placebo. A new Cochrane review on TENS for chronic pain is underway.

As for chronic low back pain, in particular, a Cochrane review of four studies concluded that the evidence was conflicting, and thus the efficacy of TENS was unclear. However, a large observational study in Orthopedics analyzed data for Medicare patients with chronic low back pain and found that those using TENS required fewer pain-related hospital stays or doctors’ visits than those not using the devices.

The most common adverse effect of TENS is mild skin irritation where the pads are placed. The home devices, many costing less than $50, allow you to adjust the intensity (pulse frequency and amplitude) of the current and the length of the session. If you purchase a TENS unit, follow the instructions to ensure that you use it safely. For example, electrodes shouldn’t touch each other and shouldn’t be placed on the front or side of the neck. Pregnant women and people with epilepsy, deep-vein thrombosis, a pacemaker, or an implanted defibrillator should consult a doctor before using TENS.

Also see Back Pain Home Remedies.