Curr Rev Musculoskelet Med (2008) 1:39–47 at 6, 12, and 26 weeks after intervention, with 12 weeks being the primary time point. In addition, safety of the yoga and exercise classes as well as adherence to class and home practice in both of these groups were assessed. The three groups were generally matched with regard to baseline characteristics. The typical participant was a col- lege-educated, working, white woman between the ages of 40 and 50 years old. Two-thirds of participants reported having back pain for more than 1 year. Few subjects reported work loss or signiﬁcant activity restrictions due to back pain, but more than one-half had taken medications in the week before the study. The Roland disability score decreased in all three groups over the course of the study; however the mean Roland scores, adjusted for baseline scores, were signiﬁcantly different among the three groups at all three follow-up time points. The yoga group showed statistically and clinically important improvements in dis- ability at all follow-up points compared to the book group. Although the yoga group had signiﬁcantly greater improvements in disability compared to the exercise group at 12 weeks, the differences were clinically unimportant. ‘‘Bothersomeness’’ of symptoms also decreased in all three groups during the 12-week intervention period; however, between weeks 12 and 26, symptoms continued to improve only in the yoga group whereas participants in the exercise and book groups experienced worsening symptoms. At 6 and 26 weeks, the yoga group experienced clinically and statistically signiﬁcant reductions in symptoms compared with the book group. At the primary time point of 12 weeks, however, there were no statistically signiﬁcant differences among the three groups. Finally, there were no signiﬁcant differences between the three groups over time for the Short Form-36 Health Survey or degree of restricted activity. Medication usage, however, which was similar among groups at baseline decreased most sharply in the yoga group. Notably, no serious adverse events were reported in the yoga or exercise groups. Finally, class attendance was similar in the yoga (median classes atten- ded, 9) and exercise (8) groups; more than 75% of participants in both groups also reported practicing at home for an average of three or more days per week. The authors concluded that yoga was more effective than a self-care book in reducing pain and improving functional status in patients with CLBP. Furthermore, they stated these beneﬁts appeared to persist for at least several months after intervention. On the other hand, while the yoga group consistently reported superior outcomes com- pared to the exercise group, none of these differences was statistically signiﬁcant. Finally, the authors noted the yoga intervention was safe and had moderately good adherence. In conclusion, the authors suggested that the Viniyoga style of yoga was an effective and safe treatment for patients with nonspeciﬁc CLBP. 43 Making sense of the yoga literature Of the four studies discussed above, the Sherman et al. trial is the only study that has high methodological quality and is adequately powered for statistical results. The Galantino and Jacobs studies provide published concept validity for the use of yoga in the management of CLBP. The Williams trial is a small study suggesting statistical trends for the efﬁcacy of yoga above an educational group in individuals with nonspeciﬁc LBP. Overall, the available literature suggests that a yoga intervention may decrease pain and improve function in the CLBP population. In addition, yoga appears to be a safe treatment option for the LBP patient with moderately good adherence. The precise mechanism that underlies the therapeutic effects of yoga is unclear, but it appears to work on physical and mental factors that are associated with LBP. Yoga is generally believed to improve ﬂexibility, strength, balance, and agility. For patients with LBP, yoga appears to address imbalances in the musculoskeletal system affecting spinal alignment and posture. For example, yoga targets many muscle groups with the aim of lengthening tightened muscles and strengthening often underutilized core muscles. In fact, in studies of patients with LBP, yoga has been found to increase hip ﬂexion as well as spinal and hamstring ﬂexi- bility [4, 7]. As discussed above, however, the practice of yoga places as much emphasis on relaxation and meditation as on physical movement. The mental focus induced by yoga likely helps people increase their awareness of how they position and move their body in maladaptive ways and relax tense muscles. In addition, yoga is generally believed to reduce stress and improve mood and overall well-being; these effects are likely enhanced by the breathing techniques taught as part of the yoga practice. Pilates Pilates is another popular form of mind–body exercise where the focus is on controlled movement, posture, and breathing. Joseph H. Pilates developed the comprehensive program known as the Pilates method in the 1920’s. The dance community initially embraced Pilates as a method of conditioning ballet and modern dancers. Over the last decade, the popularity of this exercise has grown, and Pi- lates is now used as both a form of ﬁtness and holistic health. There are no published statistics regarding the number of people who practice Pilates in the United States today; however like yoga, Pilates classes now have a ubiquitous presence in health and ﬁtness clubs. In addition, private Pilates studios are common and typically offer both group mat classes as well as private sessions on specialized apparatus.