Purpose: To evaluate the effect of yoga on chronic low back pain, we conducted a pilot, randomized, two-arm, open-label, wait-list controlled, clinical trial.

This paper presents baseline data in the context of discussing the unique challenges and particular issues that must be addressed with any rigorous research of the medical applications of Hatha yoga practice.

Methods: Fifty-two patients with back pain for at least 3 months were randomized to receive 12-weeks of twice weekly Iyengar yoga or wait-list control with an educational booklet. Data collection occurred at baseline, 4 weeks and 12 weeks.

Primary outcomes of interest included between-group differences in changes scores on the Roland-Morris Disability Questionnaire, Oswestry Disability Index, and pain severity using a numeric rating scale.

Secondary outcomes of interest included between-group changes scores in anxiety, insomnia, depression, global well-being, as well as cortisol, and DHEA levels.

Results: Recruitment for the study began on January 10, 2003 and ended on March 27, 2003. A total of 177 people were screened for the study by phone. 52 (71%) were randomized to one of two groups in the study. Average age was 43.4 (25-65), and average duration of back pain was 11.3 years. Average intensity of pain was 4.2 out of 10 point maximum score.

Baseline demographic and clinical data were similar between groups. Overall, 64% of participants assigned to receive the immediate yoga intervention attended yoga classes throughout the 3-month intervention period. On average, these participants attended 15 (66%) classes over the 3-month trial period. Data collection for the 3-month time interval was completed by 84% of all participants without differences between groups.

Conclusion: To the best of our knowledge, this report is the first description of a randomized clinical trial published on the effect of yoga for back pain and the first yoga trial published using an expert panel to develop a yoga intervention through consensus. This trial provides evidence of the feasibility of creating a yoga protocol through expert panel consensus, and of recruiting participants expeditiously. This study demarcates the beginning stages of conducting rigorous clinical effectiveness research in the therapeutic application of yoga for back pain. Methodological challenges have been outlined and discussed to facilitate future research by investigators interested in conducting clinical trials on the therapeutic application of yoga for medical conditions.