Inversion Tables and Back Pain

Often I am asked for my opinion about the inversion tables shown on informercials and whether they are helpful for back pain.

The idea behind inversion and the traction generated on the spine seems reasonable.  Despite the widespread use of inversion and traction, little is known of the mode of effect, and application remains largely anecdotal.

Here some of the things that studies have shown as outcomes of inversion:

• “Inverted positioning for short periods significantly increased spinal length and reduced EMG activity of the superficial lumbar area musculature of normal males.” (Arch Phys Med Rehabil. 1978 Aug;59(8):367-70.)
• There is evidence that inversion has a “a vagotonic influence upon the cardiovascular system” and also “such vagotonic effects are also operative in the nervous system and thus cause decreased electrical activation of the resting musculature.” What is more, “a two minute period appears to be sufficient and the effect may persist for as much as two hours.” (Am J Phys Med. 1985 Jun;64(3):119-29.)

A few reported side effects of inversion traction include (Arch Phys Med Rehabil. 1985 Feb;66(2):100-2.):

• Periorbital and pharyngeal petechiae
• Persistent headaches
• Persistent blurred vision
• Contact lens discomfort
• Increase in intraorbital pressure

So, although these devices make lumbar traction practical in a home setting, their use should be under medical supervision because of possible side effects.

Generally speaking, these inversion tables are worth thinking about if someone has back pain symptoms.  People have tried lots of worse things over time.  There is limited evidence, though, to suggest that inversion is better than placebo treatments for back pain.  However, for some folks they may work great.  Potential side effects should be considered before use and a physician should be consulted. 

Extrapolating data from traction (not necessarily inversion) from broader studies, this type of intervention is more likely to be helpful for “patients with acute (less than 6 weeks' duration) radicular pain [or sciatica type symptoms]…  The apparent lack of a dose-response relationship suggests that low doses [as little as 2 minutes based on the above listed studies] are probably sufficient to achieve benefit.” (Man Ther. 2000 May;5(2):72-81.)