"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.