42 3 months duration or longer were randomized to one of the two groups including 20 to the yoga group and 24 to the control group. The yoga intervention was developed by consultation with senior Iyengar instructors who had experience with a yoga protocol for CLBP. Iyengar instructors taught the 90-min class which consisted of a progression of 29 postures weekly for 16 weeks. In addi- tion, yoga participants were encouraged to practice yoga at home for 30 min, 5 days per week. The educational control group received newsletters on back care as well as two 1-h lectures consisting of physical and occupational therapy education. The primary outcome measure was functional disability, measured with the Pain Disability Index (PDI). Secondary outcome measures included pain intensity assessed with the Short Form-McGill Pain Questionnaire (SF-MPQ); psychological (pain attitudes, fear of movement and self- efﬁcacy) and behavioral (coping strategies) outcomes; spinal range of motion; and pain medication usage. All outcome measures were assessed at baseline, post-treat- ment and at 3-month follow-up. Finally, adherence to home-based yoga practice was also assessed. At baseline, there were no signiﬁcant differences in demographics and medical history between the yoga and the control groups. The average participant had a mean age of 48.3 (range of 23–67 years) and an average duration of LBP for 11.2 years. In addition, there were no signiﬁcant differences between groups at baseline for most outcome variables. The authors noted that the participants were relatively healthy in terms of pain and disability. Post- treatment, the yoga group had signiﬁcantly lower PDI scores for functional disability versus baseline compared to the control group with the yoga group’s mean scores falling 76.9% and the control group 39.6%. The greater improvement in functional disability for the yoga group was maintained at a 3-month follow-up. In addition, yoga participants had statistically signiﬁcant reductions in pain compared to the control group at a 3-month follow-up; the yoga group reported a 70% decrease in pain compared to a 38% reduction in the control group. Finally, drug usage post-treatment decreased signiﬁcantly in the yoga group compared to the control group; 88% of the participants in the yoga group reported decreasing or stopping their medication compared to 35% in the control group. At a 3- month follow-up, both groups reported further decreases in pain medication usage but the yoga group continued to report signiﬁcantly greater reductions than the control group. On the other hand, no signiﬁcant differences were found for the other secondary outcome measures including psychological and behavioral factors and spinal range of motion. Finally, regarding adherence to home practice, participants in the yoga group reported practicing an average of 52 min per week. Curr Rev Musculoskelet Med (2008) 1:39–47 The authors concluded that yoga therapy resulted in greater beneﬁts for patients with CLBP compared to an educational program. Speciﬁcally, they stated their data showed that a yoga intervention could signiﬁcantly reduce disability and pain and decrease use of pain medications in such patients. Furthermore, because signiﬁcant improve- ments were maintained at 3 months, the authors concluded that yoga was associated with longer lasting reductions in disability and pain than an educational intervention. Regarding the lack of change in psychological and behavioral factors as well as spinal range of motion, the authors stated that their study did not have enough power to obtain statistical signiﬁcance for these secondary out- comes. In addition, they postulated the duration of time necessary to change long-held negative beliefs such as fear of movement might be longer than the time required to improve perceptions of disability and pain. The seminal trial of yoga for low back pain Sherman and colleagues conducted a randomized con- trolled trial in 2005 comparing the effects of yoga classes to conventional exercise classes and a self-care book in patients with LBP [6]. One hundred and one subjects with nonspeciﬁc LBP of at least 12 weeks duration and a history of a recent visit to primary care for this complaint were enrolled in the study. Participants were then randomly assigned to one of the three interventions including 36 participants to the yoga class, 35 to the conventional exercise class, and 30 to the self-care book. Exclusion criteria included subjects with sciatica, spinal stenosis, signiﬁcant discogenic symptoms, or any ongoing com- pensation issues. The Viniyoga style of yoga was chosen with each class designed by a senior Viniyoga teacher using a core of 17 postures speciﬁcally geared for patients with LBP who did not have any previous yoga experience. For the exercise intervention, a physical therapist created classes incorporating aerobic conditioning, strengthening exercises that emphasized leg, hip, abdominal, and back muscles, and stretching. The instructors taught these 75- min classes twice weekly for 12 weeks. In addition, all yoga and exercise class participants were encouraged to practice at home daily. Finally, subjects randomized to the self-care book received an evidence-based book that emphasized self-care strategies for LBP. Primary outcome measures included back-related func- tional status assessed with the modiﬁed Roland Disability Scale and ‘‘bothersomeness’’ of pain assessed with an 11- point numerical scale. Secondary outcome measures inclu- ded general health status measured with the Short Form-36 Health Survey, degree of restricted activity, and medication usage. All outcome measures were assessed at baseline and