“Oh, my aching back!” may be heard less frequently as people with chronic lower back pain find some relief from a therapeutic form of yoga, a new study suggests.

Yoga is often promoted as a way to ease lower back pain and other chronic body aches, but there have been few rigorously conducted studies on the subject.

For the current study, published in the journal Spine, researchers randomly assigned 90 adults (average age 48, range 18-70) with chronic lower back pain to either stay with conventional care or take six months of Iyengar-style yoga classes.

Iyengar is a form of yoga that emphasizes proper body alignment and uses “props,” such as blocks, blankets and the wall, to help support people in the various yoga postures. The certified Iyengar yoga instructors in this study had experience using yoga therapy for back pain.

Overall, the researchers found, the yoga group showed not only greater improvements in pain and mobility, but also a larger reduction in depression symptoms. And the benefits were seen immediately after the six-month yoga regimen ended, as well as six months later.

The findings do not mean that every style of yoga is right for back-pain sufferers.

“People have to remember that this was a therapeutic Iyengar class,” lead researcher Dr. Kimberly Williams, of West Virginia University in Morgantown, said in an interview.

She recommended that people with lower back pain who are interested in trying Iyengar yoga find a certified teacher with the experience to help them adjust the poses to their needs. That means talking with the teacher before starting a class, and keeping him or her posted on how the back problem is faring, according to Williams.

The study subjects had been suffering lower back pain for more than three months. About half took twice-weekly yoga classes for 24 weeks (n = 43), while the rest were put on a 6-month waiting list while staying with usual care, such as pain medication (n = 47).

After 24 weeks, the yoga group reported greater improvements in pain and disability, on average, than the comparison group. And while none of the study participants had major depression, the yoga group’s scores on a standard measure of depression symptoms improved to a greater degree than the comparison group’s.

When the researchers evaluated the patients six months later, they found that the yoga group was still faring better, on average.

There was a “specific rationale” behind the pose choices and sequencing used in the study, Williams noted. Because all of the muscles that act on the pelvis can affect lower back pain, the classes focused on those muscles, with postures that “opened” the hips and stretched the backs of the legs, for example. Backbends, a staple in many yoga classes, were excluded.

People in the yoga group were also given a DVD, written instructions, and props to keep up a home practice.

“I think people with lower back pain need to be engaged in their recovery,” Williams said. “And this gives them a step-by-step approach to do that.”

SOURCE: Spine, September 2009.