The study, published in this month's issue of the journal Spine, was a three-year, $400,000 research project funded by National Institutes of Health. Researchers assigned 90 people with chronic back pain to a yoga group or a control group that received standard medical care.
The use of pain medication was reduced, but that reduction was similar in both groups.
"The yoga group had less pain, less functional disability and less depression compared with the control group," said Kimberly Williams, the lead investigator from West Virginia University, in a news release. "Proponents of yoga have long described its benefits in reducing back pain. But not everyone was convinced. This is a much bigger, much more rigorous evaluation than had been done before."
The classes were taught by an instructor certified in Iyengar yoga, which emphasizes posture.