October 1, 2011

Yoga eases back pain in largest U.S. yoga study to date

Group Health randomized controlled trial in Archives of Internal Medicine

Yoga  classes were linked to better back-related function and diminished symptoms  from chronic low back pain in the largest U.S. randomized controlled trial of yoga to date, published by the Archives of  Internal Medicine as an “Online First” article on October 24. But so were intensive stretching classes.

“We found yoga  classes more effective than  a self-care book—but no more effective than stretching classes,” said study leader Karen  J. Sherman, PhD, MPH, a senior investigator at Group Health Research Institute. Back-related  function was better and symptoms were diminished with yoga at 12 weeks; and clinically  important benefits, including less use of pain medications, lasted at least six months for both yoga and stretching, with thorough follow-up of more than nine in 10 participants.

In the trial, 228 adults in six cities in western Washington state were randomly assigned to 12 weekly 75-minute classes of either yoga or stretching exercises or a comprehensive self-care book called The Back Pain Helpbook. Nine in 10 of  them were primary-care patients at Group Health Cooperative. Participants in the trial typically had  moderate—not severe—back pain and relatively good mental health, and most had  been at least somewhat active before the trial started.

The class participants received instructional materials and were encouraged to practice at home for 20 minutes a day between their  weekly classes. Interviewers who didn’t know the patients’ treatment assignments assessed their back-related function and pain symptoms at six weeks, 12 weeks, and six months.

In 2005, Dr. Sherman and her colleagues conducted a smaller study that found yoga effective  for easing chronic low back pain. “In our new trial,” she said, “we wanted both to confirm those results in a larger group and to see how yoga compared to a different form of exercise of comparable physical exertion: stretching.

Both the yoga and stretching classes emphasized the  torso and legs:

  • The type of yoga used in the trial, called viniyoga, adapts the  principles of yoga for each individual and physical condition, with modifications for people with physical limitations. The yoga classes also used breathing exercises, with a deep relaxation at the end.
  • The stretching classes used 15 different stretching exercises, including stretches of the hamstrings and hip flexors and rotators. Each was held for a minute and repeated once, for a total of 52 minutes of stretching. Strengthening exercises were also included.

“We expected back pain to ease more with yoga than with stretching, so our findings surprised us,” Dr. Sherman said. “The most straightforward interpretation of our findings would be that yoga’s benefits on  back function and symptoms were largely physical, due to the stretching and strengthening of muscles.”

But the stretching classes included a lot more stretching than in most such classes, with each stretch held for a relatively long time. “People may have actually begun to relax more in the stretching classes than they would in a typical exercise class,” she added. “In retrospect, we realized that these stretching classes were a bit more like yoga than a more typical exercise program would be.” So the trial might have compared rather similar programs with each  other.

“Our results suggest that both yoga and stretching can be good, safe options for people who are willing to try physical activity to relieve their moderate low back pain,”  Dr. Sherman concluded. “But it’s important for the classes to be therapeutically oriented, geared for beginners, and taught by instructors who can modify postures for participants’ individual physical limitations.”

In an invited commentary, Timothy S. Carey, MD, MPH, of the  University of North Carolina, Chapel Hill, called Dr. Sherman’s study “an excellent example of a pragmatic comparative effectiveness trial,” noting that  the Institute of Medicine has identified chronic back pain as a priority condition for such studies.

The National Center for Complementary and Alternative  Medicine, part of the  National Institutes of Health, funded the trial.

Dr. Sherman’s coauthors were Daniel C. Cherkin, PhD, Robert D. Wellman, MS, Andrea J. Cook, PhD, Rene J. Hawkes, and Kristin  Delaney, MPH, of Group Health Institute; and Richard A. Deyo, MD, MPH, of Oregon Health and Science University in Portland. Drs. Sherman, Cherkin, and Cook are also on the  faculty of the University of Washington School of Public Health.

Archives of Internal Medicine

The Archives of Internal Medicine is an international peer-reviewed journal providing innovative and clinically relevant research for practitioners in general internal medicine and internal medicine subspecialities. Published by the American Medical Association, the journal strives to publish articles that are stimulating to read, educate and inform readers with the most up-to-date research, and lead to positive change in our health care systems and the way we deliver patient care. See http://archinte.jamanetwork.com/.

About Kaiser Permanente Washington Health Research Institute

Kaiser Permanente Washington Health Research Institute (KPWHRI), formerly Group Health Research Institute, improves the health and health care of Kaiser Permanente members and the public. The Institute has conducted nonproprietary public-interest research on preventing, diagnosing, and treating major health problems since 1983. Government and private research grants provide our main funding. Follow KPWHRI research on Twitter, Facebook, Pinterest, LinkedIn, or YouTube. For more information, go to: www.kpwashingtonresearch.org.

About Kaiser Permanente 

Kaiser Permanente is committed to helping shape the future of health care. We are recognized as one of America’s leading health care providers and not-for-profit health plans. Founded in 1945, Kaiser Permanente has a mission to provide high-quality, affordable health care services and to improve the health of our members and the communities we serve. We currently serve more than 11.3 million members in eight states and the District of Columbia. Care for members and patients is focused on their total health and guided by their personal physicians, specialists, and team of caregivers. Our expert and caring medical teams are empowered and supported by industry-leading technology advances and tools for health promotion, disease prevention, state-of-the-art care delivery, and world-class chronic disease management. Kaiser Permanente is dedicated to care innovations, clinical research, health education, and the support of community health. For more information, go to: kp.org/share.

Additional study researchers

Daniel C. Cherkin, PhD

Senior Investigator (Emeritus)
Kaiser Permanente Washington Health Research Institute

Robert D. Wellman, MS

Biostatistician
Kaiser Permanente Washington Health Research Institute

Andrea J. Cook, PhD

Senior Investigator
Kaiser Permanente Washington Health Research Institute