The Science of Yoga

practice of modern yoga and ultimately helped make it safer—albeit after considerable resistance. Initially, some yogis challenged the reports as biased and mean-spirited. Others, perhaps taken with the mother’s milk argument, tried to ignore the criticism or shrug off the injuries as an inconspicuous cost of doing business.
    In recent years, the best teachers have responded to the warnings with new sensitivity (and better insurance policies). They put safety first, caution their students to proceed with care, and reject the one-size-fits-all mentality of early styles and instructors.
    To yoga’s credit, a number of knowledgeable practitioners have recently stepped forward to confront the physical threats quite directly in articles, books, bibliographies, and—most recently—detailed surveys of yoga injuries. The activists are generally reformers who seek to raise awareness of the dangers and offer precautions. The surveys, which can be alarming, suggest that yoga’s recent popularity has created a rush of inexperienced teachers. Ironically, it seems that idyllic vacation spots are particularly treacherous.
    Robin is one of the reformers. His books feature lengthy addendums that detail some of the ways in which yoga can go wrong. They tell of paralyzed limbs, bulging eyeballs, damaged brains—among other varieties of destruction, some verging on the bizarre. The appendices reflect his careful reading of the medical literature. They portray a hidden world of major trauma as well as minor problems such as sprains and torn muscles, which turn out to be surprisingly common. In his Pennsylvania class, we practiced a number of precautions, especially on how to unburden the neck in the Headstand and Shoulder Stand.
    As a group, theactivists tend to be in closer alignment with the findings of science than yoga traditionalists. Just as Robin and his Iyengar colleagues have redesigned the Headstand, some of the reformers have focused on reinventing some of the most dangerous poses or advising students to drop them altogether.
    Such reevaluations may go against yoga’s timeless image. But as we have seen, yoga has proved itself quite flexible in adapting to the needs and desires of different ages. Today, the long silence of the gurus has given way to scientific inquiries that are nurturing new strategies for injury prevention. The reform movement is a happy case study in what can happen if yoga and science cooperate, even grudgingly. The inconspicuous wave of reinvention promises to benefit millions of students around the globe and, not insignificantly, to help modern yoga live up to its good reputation.
    In my travels, I learned of an experienced yogi who was said to know the inside story on yoga injury. Prominent gurus had supposedly come to him for help in rehabilitation and recovery. One client was reported to have received a hip replacement before reentering the celebrity life. I decided to track him down.
    Glenn Black had traveled to India, studied at Iyengar’s school in Pune, and, like the ancient yogis, spent years in solitude. He ran yoga intensives in the jungles of Costa Rica. In New York City, for a decade, he studied with Shmuel Tatz, a Lithuanian who devised a unique method of physical therapy that he dispensed from offices above Carnegie Hall to actors, singers, dancers, musicians, composers, and television stars. Black had settled down in Rhinebeck, New York, on the Hudson River. Honored as a master teacher and anatomist, he often taught yoga at the nearby Omega Institute, a New Age emporium. Black had a devoted following drawn to his earthy, no-nonsense style. He also had an elite bodywork clientele that included celebrities. Of late, he was said to have narrowed his client list down to a handful of billionaires.
    One day I noticed that Black was scheduled to teach a master class in Manhattan. I hesitated but was told that resolve was more important than skill. I arranged to talk with him afterward.
    On a cold Saturday in early 2009, I made my way to Sankalpah (aim, will, determination) Yoga, a third-floor walkup on Fifth Avenue between Twenty-Eighth and Twenty-Ninth. The room was filled with lean bodies, roughly half of the individuals said to be teachers.
    The class was brutal. Black joked, walked around a lot, talked constantly, played jazz on the sound system, watched us like a hawk, and cajoled relentlessly. Beads of sweat turned into rivulets. He was highly demanding yet surprisingly gentle,