When a major medical journal such as the Archives of Internal Medicine publishes a clinical trial showing the effects of yoga for low back pain, the yoga community (and increasingly, the medical establishment) sits up and takes notice. The study, which came out yesterday, was long awaited and is the best of its kind in organization, sheer brute numbers and statistical analysis. Nevertheless, I am eager to see more work done on this important topic, and I suspect the study's lead investigator, Karen Sherman from the Group Health Research Institute in Seattle, would agree. The clinical trial suggests that yoga helps people with their back pain. It does not show any psychological or behavioral benefit to yoga vs. stretching in the sample of people it selected.
To both simplify and narrow results by using a homogeneous group of participants, this excellent study excluded participants who had some common categories of back pain. People who had herniated discs and spinal stenosis (narrowing of the spinal column), for example, were disqualified in an effort to prove yoga's value for the generic symptom "low back pain." (Non-yoga clinical trials of back pain are often set up the same way, and my opinion about them is the same.)
Back Pain From Specific Conditions
Yoga therapists often treat different conditions, such as stenosis or herniated disc, in completely different ways, as do medical doctors like myself. For example, yoga is frequently used to treat a herniated disc by extending the back, by bending backward; people who have spinal stenosis find relief by doing yoga that emphasizes flexion, or bending forward. By looking at back pain as a generic problem rather than as a problem with different causes, Karen Sherman's group took a necessary first step, and it was successful. Both yoga and stretching (and let's face it, yoga involves stretching) help garden variety chronic low back pain.
Now I hope future studies of yoga and back pain can examine individual treatments for specific conditions such as herniated disc and stenosis, and do so on a one-on-one basis as yoga was taught in ancient times, rather than in large classes. Yoga classes are an artifact of urban economics: Yoga teachers cannot make a living without pooling fees that way. It's the same in medical school: pretty big classes. But the doctor sees patients one at a time, and the yoga therapist usually does the same thing, or sees very small groups of two or three patients. The true value of yoga, like the true value of any medical treatment, may be indicated by large studies, but the best, most relevant information may be found by studying the results of individual treatment. And collecting information by studying patients one by one may contribute to understanding the less tangible effects of practicing yoga -- psychological, behavioral and even spiritual.
Less-Tangible Benefits of Yoga
A survey of 33,000 yoga teachers and therapists worldwide that I did with several colleagues in 2008 and published in the Journal of the Association of Yoga Therapists, found that most people begin doing yoga for physical or general psychological reasons: "shoulder pain" or "want to relax," but that if they do yoga regularly for more than a year, they do it for the psychological benefits more than for any other reason. Those results were duplicated in an Australian national survey.
The spiritual element in yoga is difficult to capture in large groups and perhaps difficult to quantify at all using Western techniques of randomized controlled trials. But with researchers like the group in Seattle thinking about these problems, going forward we are likely to find answers.