By the way, doctor: Do inversion tables work?

Q. What do you think about using inversion tables to relieve back pain?

A. Inversion tables are one type of "inversion therapy," which involves adopting an upside-down posture to reverse the effects of gravity on the spine. The head is tilted downward on a table, allegedly to relieve pressure on the discs and nerve roots in the spine and increase the space between vertebrae. Proponents claim that inversion table therapy not only relieves back pain but also improves posture, preserves height, increases flexibility, stimulates blood flow to the brain and scalp, corrects the position of abdominal organs, and relieves varicose veins. None of these assertions has any scientific basis.

Experts regard inversion tables as a form of spinal traction. Instead of increasing disk space, traction is more likely to stretch the muscles and ligaments around the spine and temporarily relieve muscle spasm. That may be why some people get short-term relief from back pain after lying on an inversion table. But spinal traction doesn't provide long-term relief. A 2006 Cochrane Review (a summary of evidence from randomized trials) concluded that there was no evidence to recommend traction for the treatment of low back pain.

Using an inversion table is not without risk: it raises blood pressure, lowers heart rate, and increases pressure in the eye. In some users, it has caused bleeding into the retina. It's also been associated with headache and blurred vision. Don't use an inversion table if you're pregnant or if you have high blood pressure, heart disease, or glaucoma or any other eye disease.

Some physical therapists may incorporate short-term inversion table therapy, under supervision, in a comprehensive program for back pain. That's the only setting in which I would consider use of an inversion table.

— Celeste Robb-Nicholson, M.D.
Editor in Chief, Harvard Women's Health Watch