TENS is widely available and widely advertised, but "just because it is popular doesn't mean that it works," Dubinsky said. Approval of TENS by the U.S. Food and Drug Administration doesn't mean much either, he added.
"The threshold for approval by the FDA is different for devices than for pharmaceuticals," Dubinsky said. "For a device, you just have to prove that it is safe. For a pharmaceutical, you have to prove that it is safe and effective."
It's possible that TENS is effective against some forms of pain, such as what is experienced after surgery, but such studies haven't been done, he said.
The demand for relief of back pain -- acute and chronic -- is large; the U.S. National Institute of Neurological Disorders and Stroke estimates that it is the second-most common neurological ailment in the country. It is estimated that about one-quarter of all Americans experience some sort of back pain in any given three months.
Effective treatments for back pain include exercise, stretching and anti-inflammatory medications, including over-the-counter nonsteroidal drugs (NSAIDs) such as ibuprofen, Dubinsky said.
Causes and treatment of back pain are described by the U.S. National Library of Medicine.
SOURCES: Richard M. Dubinsky, M.D., M.P.H., professor, neurology, Kansas University Medical Center, Kansas City; Dec. 30, 2009, Neurology, online
All rights reserved