The Science of Yoga

lessons for the medical community, Fong and his colleagues argued. The main one was the importance of learning the inconspicuous details of case history, which if taken seriously could speed diagnosis and treatment. Their warning echoed Russell’s observation about overlooking the origin of brain damage.
    The gravity of theHong Kong case, the team concluded, showed that yoga could pose extraordinary risks to human health. The doctors cautioned that postures in which the neck came under great strain could be “potentially dangerous or even lethal.” The latter word is one that physicians, steeped in a culture of cautious optimism and dry understatement, tend to avoid if possible.
    The spike in clinical reports made yoga strokes a common feature of medical concern. The danger was judged to be at least partly due to underlying weaknesses in the vertebral arteries of some individuals. But it was difficult if not impossible to know who was at risk. So the warnings spread. They appeared not only in medical journals but in textbooks as health specialists gained new appreciation of the threat.
    Science of Flexibility , whose first edition appeared in 1996, featured a section called X-Rated Exercises. It linked strokes to poses that stretched the neck far backward, including the Wheel and the Cobra. In summarizing the medical findings, the book’s author called the value of the postures too small “to justify the potential, although rare, risk of vertebral artery occlusion.” He suggested avoidance.
    Injuries due to yoga turned out to range far beyond nerve damage and strokes. Waves of practitioners were showing up in emergency rooms. The Consumer Product Safety Commission, in monitoring the hazards of modern life, runs a little-known detective service known as the National Electronic Injury Surveillance System. It samples hospital records in the United States and its territories. By 2002, its surveys showed that the number of admissions related to yoga, after years of slow increases, had begun to soar. The number of admissions went from thirteen in 2000 to twenty in 2001. Then, in 2002, they more than doubled to forty-six. By definition, all these episodes involved men and women (and in some cases children) who had hurt themselves badly enough to seek out emergency assistance.
    The spike represented the tip of a very large iceberg, since the system of federal monitoring produced only a statistical sketch. Most emergency rooms lay beyond its reach. Moreover, only a fraction of the injured visited hospital emergency rooms in the first place. Many—perhaps most—went to family doctors, chiropractors, neighborhood clinics, drugstores, and various kindsof therapists. Some probably decided to avoid treatment altogether and deal with the injury on their own. Thus, many hundreds or even thousands of yoga injuries in the United States went unreported.
    The 2002 survey, like that of any year, gave a brief description of each person and each injury. An analysis of the information on the forty-six patients showed that they ranged in age from fifteen to seventy-five years, with the average age being thirty-six. The vast majority—83 percent—were women. The main type of injury centered on the complicated amalgams of bone, tendon, and cartilage known as joints, including the wrist (mentioned six times), the ankle and foot (five times), the knee (five times), the shoulder (four times), and the neck (four times). The injury write-ups contained an area for brief comments, which tended to describe everyday pains, strains, and sprains. But the comments also disclosed a number of serious traumas. Six of the injuries involved dislocations and fractures.
    The survey listed no strokes—their diagnosis would typically require detailed examinations that went beyond the simple capabilities of most emergency rooms—but in several cases listed symptoms that might have coincided with the precipitating damage. “Acute neck pain,” read one write-up. “Collapsed to floor while performing yoga,” read another.
    The brief comments tended toward the kind of pithy diagnoses and observations heard in emergency rooms: “dislocated right knee,” “hurt shoulder,” “low back pains.” The reports usually cited yoga in general as the cause of the accident but on occasion named specific poses. “Sharp pain in abdomen since doing Cobra,” read one report. Another said a male patient fainted while doing yoga in a warm room, falling and hitting