Evaluation of the effectiveness and efficacy of Iyengar yoga therapy on chronic low back pain.

Abstract

The effectiveness and efficacy of Iyengar yoga for chronic low back pain (CLBP) were assessed with intention-to-treat and per-protocol analysis. Ninety subjects were randomized to a yoga (n = 43) or control group (n = 47) receiving standard medical care. Participants were followed 6 months after completion of the intervention. This study aimed to evaluate Iyengar yoga therapy on chronic low back pain. Yoga subjects were hypothesized to report greater reductions in functional disability, pain intensity, depression, and pain medication usage than controls. CLBP is a musculoskeletal disorder with public health and economic impact. Pilot studies of yoga and back pain have reported significant changes in clinically important outcomes. Subjects were recruited through self-referral and health professional referrals according to explicit inclusion/exclusion criteria. Yoga subjects participated in 24 weeks of biweekly yoga classes designed for CLBP. Outcomes were assessed at 12 (midway), 24 (immediately after), and 48 weeks (6-month follow-up) after the start of the intervention using the Oswestry Disability Questionnaire, a Visual Analog Scale, the Beck Depression Inventory, and a pain medication-usage questionnaire. Using intention-to-treat analysis with repeated measures ANOVA (group x time), significantly greater reductions in functional disability and pain intensity were observed in the yoga group when compared to the control group at 24 weeks. A significantly greater proportion of yoga subjects also reported clinical improvements at both 12 and 24 weeks. In addition, depression was significantly lower in yoga subjects. Furthermore, while a reduction in pain medication occurred, this was comparable in both groups. When results were analyzed using per-protocol analysis, improvements were observed for all outcomes in the yoga group, including agreater trend for reduced pain medication usage. Although slightly less than at 24 weeks, the yoga group had statistically significant reductions in functional disability, pain intensity, and depression compared to standard medical care 6-months postintervention. Yoga improves functional disability, pain intensity, and depression in adults with CLBP. There was also a clinically important trend for the yoga group to reduce their pain medication usage compared to the control group.