The Science of Yoga

Iyengar claims, the Headstand is “the king of all asanas,” its kingdom has undergone much contraction.
    Other postures that have suffered banishment in some circles include the Full Lotus—one of yoga’s most venerable poses. “Knees are hinge joints, meant only to bend and straighten, not twist,” Dawn Mcenter1ear, a yoga teacher in Washington, DC, told the readers of Health magazine.
    One of the most prolific reformers is Roger Cole, an Iyengar teacher with degrees from Stanford and the University of California who specializes in yoga anatomy and safety. He writes extensively for Yoga Journal and has spoken on yoga safety to the American College of Sports Medicine. Notably, Cole has drawn consistently on science to document the risky aspects of yoga postures and recommend safe practices.
    In one column, he discussed how to reduce neck bending in the Shoulder Stand by lifting the shoulders on a stack of folded blankets and letting the head fall below that level, as we had practiced in Robin’s class. In theory, that could increase the angle between the head and the torso from 90 degrees to perhaps 110 degrees. Cole also voiced rare criticism of Iyengar. He said the guru in Light on Yoga may have “inadvertently contributed” to neck injuries by calling for a perfectly vertical Shoulder Stand. Instead, Cole wrote, teachers should instruct students “to rest their weight toward the back of their shoulders and jackknife the body enough to take pressure off the neck.”
    Cole ticked off the dangers of doing the Shoulder Stand without such precautions. His list included muscle strains, overstretched ligaments, and cervical disk injuries. Strangely, he said nothing about strokes.
    Eventually yogis sought to map the world of injuries by means of practitioner surveys. The questionnaires promised a better overview than the statistical surveys of the American government and, in the hands of yoga professionals, a better foundation for posture refinement and reinvention. The investigators, as was the case with many reformers, usually had backgrounds that combined yoga and science.
    In 2008, yoga researchers in Europe published a survey about practitioners of Ashtanga—the fluid style from Krishnamacharya that Holly Millea had practiced. Their study limited itself to damage of the muscles and skeleton, involved practitioners only in Finland, and produced just one hundred and tenresponses. But the results were fairly dramatic. The majority of the responders—62 percent—said they had suffered at least one injury that had lasted longer than a month, and some reported multiple upsets. The injuries were mostly sprains and strains, as well as two dislocations.
    In 2009, a New York City team based at the Columbia College of Physicians and Surgeons published a far more ambitious survey of yoga teachers, therapists, and doctors around the globe. It was done in cooperation with the International Association of Yoga Therapists, the Yoga Alliance, and Yoga Spirit, an education group in Toronto. More than 1,300 people in thirty-four countries responded. The Columbia survey asked not only for personal experiences but also observations about yoga students and patients. It appeared in the International Journal of Yoga Therapy , ensuring its wide reading among yogis interested in healing.
    The participants reported practicing Hatha and its many offspring, including Vinyasa, Iyengar, Anusara, Ashtanga, and Kripalu. The survey’s central question—“What are the most serious injuries (disabling and/or of long duration) that you have seen?”—produced a number of revelations.
    The largest number of injuries (with 231 reports) centered on the lower back. In declining order of prevalence, the other main sites were the shoulder (219 incidents), the knee (174), and the neck (110).
    Amid these generalities came more specific accounts. The respondents said they knew of forty-three times that spinal disks had herniated, seventeen times that bones had fractured, and five times that practitioners had suffered heart problems.
    Then came stroke. Its debut in a yoga survey came nearly four decades after Russell’s warning. The respondents said they had witnessed four cases—in other words, they knew of four occasions in which yoga’s extreme bending and contortions had resulted in some degree of brain damage.
    For the community, the admission was a significant step. Few yoga books ever spoke of the danger—or looked into the medical