CHICAGO -- Yoga classes were found to be more effective than a self-care book for patients with chronic low-back pain at reducing symptoms and improving function, but they were not more effective than stretching classes, according to a study published online first by the Archives of Internal Medicine.

"Despite the availability of numerous treatments for chronic back pain, none have proven highly effective, and few have been evaluated for cost-effectiveness," the authors provide as background information. "Self-management strategies, like exercise, are particularly appealing because they are relatively safe, inexpensive, and accessible and may have beneficial effects on health beyond those for back pain. One form of exercise with at least 'fair' evidence for effectiveness for back pain is yoga, which might be an especially promising form of exercise because it includes a mental component that could enhance the benefits of its physical components."

Karen J. Sherman, Ph.D., M.P.H., from Group Health Research Institute, Seattle, and colleagues designed a study to determine whether yoga is more effective than conventional stretching exercises or a self-care book for primary care patients with chronic low-back pain. A total of 228 adults with chronic low-back pain were randomized to 12 weekly yoga classes (92 patients) or conventional stretching exercise

classes (91 patients), or a self-care book that provided information on causes of back pain and advice on exercising, lifestyle modifications and managing flare-ups (45 patients). The main outcomes measured were back-related functional status and how much the back pain was bothering the patients. Telephone interviews were conducted at baseline, and at six, 12 and 26 weeks after randomization.

"Back-related dysfunction declined over time in all groups," the authors report. Compared with the self-care group, the yoga group reported superior function at 12 and 26 weeks (average difference, -2.5 and -1.8, respectively) and the stretching group reported superior function at six, 12 and 26 weeks (-1.7, -2.2, -1.5, respectively). "There were no statistically or clinically significant differences between the yoga and stretching groups" at any time point, the authors note.

"We found that physical activity involving stretching, regardless of whether it is achieved using yoga or more conventional exercises, has moderate benefits in individuals with moderately impairing low back pain. Finding similar effects for both approaches suggests that yoga's benefits were largely attributable to the physical benefits of stretching and strengthening the muscles and not to its mental components." The benefits of these approaches may last several months, the authors conclude.