The idea of acupuncture may be enough to help relieve lower back pain, say researchers who gave real and simulated pricks.

Several studies have suggested that simulated acupuncture or shallow needling on parts of the body that are not considered key acupuncture points appears to be effective as acupuncture that penetrates the skin.

In Monday's issue of the Archives of Internal Medicine, researchers in Seattle reported the results of their randomized clinical trial involving 638 adults with chronic low back — that lasted at least three months — who received four different types of treatment.

During the seven-week treatment period:

• 157 participants received 10 individualized acupuncture treatments as prescribed by a diagnostic acupuncturist.
• 158 had a standardized course of acupuncture treatments considered effective by experts for low back pain.
• 162 received 10 sessions of simulated acupuncture, in which practitioners used a toothpick inside of an acupuncture needle guide tube to mimic the insertion, stimulation and removal of needles.
• 161 received usual care, which included medication and physical therapy.

"Compared with usual care, individualized acupuncture, standardized acupuncture and simulated acupuncture had beneficial and persisting effects on chronic back pain," Daniel Cherkin of Group Health Center for Health Studies in Seattle and his colleagues wrote.

After eight weeks, 60 per cent of those receiving any type of acupuncture experienced clinically meaningful improvement in their level of functioning, compared with 39 per cent of those receiving usual care.

Symptoms improved by 1.6 to 1.9 points in the treatment groups compared with 0.7 points in the usual care group, based on a 10-point scale.

Tailoring needling sites to each point and penetration of the skin appeared to be unimportant for producing therapeutic benefits, the study's authors said.

"It remains unclear whether acupuncture or our simulated method of acupuncture provide physiologically important stimulation or represent placebo or nonspecific effects."

The mind-body connection may explain why simulated acupuncture worked as well as real acupuncture, but no knows exactly how it works.

Stimulating acuptunture points without inserting a needle may cause physiological changes that reduce pain and improve function. Or lightly touching the skin might lead to emotional or hormonal reactions that reduce pain, Cherkin said.

The trial was funded by the U.S. National Institutes of Health's National Center for Complementary and Alternative Medicine. Lhasa OMS Inc., of Weymouth, Mass., donated the acupuncture needles used in the study.

With files from The Canadian Press