Yoga is a mind-body exercise sometimes used for nonspecific low back pain.
A newstudyassessed the effects of yoga on chronic nonspecific low back pain, compared with no specific treatment, a minimal intervention, or another active treatment, with a focus on pain, function, and adverse events.
For the study, investigators searched CENTRAL, MEDLINE, Embase, 5 additional databases, and 4 clinical trials. Randomized, controlled trials of yoga treatment in patients with chronic nonspecificlow back painwere included in the study. Additionally, studies that compared yoga as an adjunct to other therapies versus those other therapies alone were also included.
Overall, the investigators included 12 trials consisting of 1080 participants that were conducted in the United States, India, and the UK. Most of the trials used Iyengar, Hatha, or Vinyasa forms of yoga. The trials compared yoga to no intervention or nonexercise intervention, such as education; an exercise intervention; or both exercise and nonexercise interventions.
Since all the trials were at high risk of performance and detection bias, the investigators downgraded all outcomes to moderate certainty evidence. When there was additional serious risk of bias, unexplained heterogeneity between studies, or imprecise analyses, the investigators downgraded the certainty of the evidence further.
When yoga was compared to nonexercise controls in 9 trials with a total of 810 participants, the results of the study showed low-certainty evidence that yoga produced small to moderate improvements in back-related function at 3 to 4 months; moderate-certainty evidence for small to moderate improvements at 6 months; and low-certainty evidence for small improvements at 12 months.
Based on a scale of 0 to 100, there was very low- to moderate-certainty evidence that yoga was slightly better for pain at 3 to 4 months, six months, and 12 months. However, the authors noted that they predefined clinically significant changes in pain as 15 points or greater and that this threshold was unmet.
Based on data from 6 trials, there was moderate-certainty evidence that the risk of adverse events—–primarily increased back pain––was higher in yoga than in non-exercise controls.
When yoga was compared to non-yoga exercise controls in 4 trials consisting of a 394 participants total, the results of the study showed there was very low-certainty evidence for little or no difference in back-related function at 3 months and 6 months, and no information on back-related function after 6 months.
Additionally, there was very low-certainty evidence for lower pain on a scale of 0 to 100 at 7 months, and no information on pain at 3 or 7 months. Based on evidence from 3 trials, there was low-certainty evidence for no difference in the risk of adverse events between yoga and non-yoga exercise controls.
When the investigators examined yoga added to exercise compared with exercise alone in 1 trial consisting of 24 participants, the results of the study showed a very low-certainty evidence for little or no difference at 10 weeks in back-related function or pain on a 0-100 scale. There was no information on outcomes at other time points or on adverse events.
The investigators noted that the studies provided limited evidence on the risk of clinical improvement, measures of quality of life, and depression. Furthermore, there was no evidence on work-related disability.
“There is low- to moderate-certainty evidence that yoga compared to non-exercise controls results in small to moderate improvements in back-related function at 3 and 6 months,” the authors wrote. “Yoga may also be slightly more effective for pain at 3 and 6 months, however the effect size did not meet predefined levels of minimum clinical importance. It is uncertain whether there is any difference between yoga and other exercise for back-related function or pain, or whether yoga added to exercise is more effective than exercise alone.”
The study findings indicated that yoga was associated with more adverse events than nonexercise controls, but that it may have the same risk as other back-focused exercise. Additionally, yoga is not associated with serious adverse events.
“There is a need for additional high-quality research to improve confidence in estimates of effect, to evaluate long-term outcomes, and to provide additional information on comparisons between yoga and other exercise for chronic nonspecific low back pain,” the authors concluded.