The Science of Yoga: The Risks and the Rewards

by William J Broad

  The Headstand became an early target. In general, teachers advised students to unburden the neck. But they seldom mentioned that such easing contradicted Iyengar. “The whole weight of the body,” the guru wrote in Light on Yoga, “should be borne on the head alone and not on the forearms and hands.”

  Richard Rosen—a teacher in Oakland, California, who had studied at the Iyengar Institute in San Francisco—called for exactly the reverse, with the complete elimination of weight from the head and neck. The idea was to suspend the head off the floor by pressing the forearms down. “If everything feels relatively comfortable,” he wrote in Yoga World, “slowly lower your crown to the floor until it just barely touches. Keep 95 percent of your weight on the forearms and shoulders.” His recommendations seemed to require a level of gymnastic skill and strength that many beginning and intermediate students would find daunting. As for the risks, Rosen never mentioned any specifically by name but simply called the Headstand “dangerous if not practiced intelligently.”

  Robin had us do Headstands in which we transferred body weight from the neck and head to the arms. With practice, it was fairly easy to do. “At this point in the game,” he remarked as we practiced the redesigned pose, “you want a maximum amount of weight on your arms—and a minimum on your head.” Someone asked how much weight should be transferred. “Seventy-two point three percent,” he replied, eliciting howls of laughter.

  Timothy McCall, a physician who became the medical editor of Yoga Journal, advocated a more drastic approach. He called the Headstand too dangerous for general yoga classes unless a teacher had a proven ability to avoid trouble. His warning was based partly on his own injury. Through trial and error, he had found that doing the Headstand had led to a condition known as thoracic outlet syndrome, which arises from the compression of nerves passing from the neck into the arms. As a result, he felt unusual tingling in his right hand as well as sporadic numbness. McCall stopped doing the pose and his symptoms went away. Later, in recommending that general yoga classes avoid the Headstand, he noted how the inversion could produce other injuries, including degenerative arthritis of the cervical spine and retinal tears because the Headstand raises eye pressure. “Unfortunately,” McCall concluded, “the negative effects of Headstand can be insidious.”

  Today, a number of schools avoid teaching the inversion or ban it outright. The cautious styles include Kripalu, Bikram, Viniyoga, and Kundalini. If, as 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 ten responses. 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 literature—and the grim topic seldom made the upbeat pages of yoga magazines. Now, a major survey done by yoga professionals had documented the threat. It was an honest first.

  Another surprise centered on judgments about what explained the injuries. The choices for survey takers included such factors as large classes, too much effort, and expanded ranks of students. A vast majority of the respondents—68 percent—pointed to “inadequate teacher training.” That was remarkable because most were teachers. In effect, they were criticizing themselves and their peers.

  The candor went to an inconspicuous deficiency of modern yoga —that teacher training varies enormously in quantity and quality, from slapdash to rigorous. You can get certified as an instructor with as little as 100 hours of training and even do the course entirely online, putting in no time whatsoever in a classroom and getting no supervision from an experienced teacher.

  Today many popular styles adhere to the minimum standards set by the Yoga Alliance, a private group in Arlington, Virginia, that seeks to build public confidence in yoga. Its definition of a yoga teacher is anyone who has participated in at least 200 hours of real training. Still, that effort—equal to four or five weeks—seems like an extraordinarily low bar in terms of serious education. Would you study with violin teacher who had trained for a month? A sculptor? A basketball player?

  Bikram is more demandi
ng. It trains its instructors for nine weeks. Yoga Alliance also endorses a category of training that requires at least 500 hours—equal to about three months.

  Compare that to Iyengar. It requires candidates for teacher training to have studied the style for a minimum of three years, and then trains them for a minimum of two years and administers two examinations to ensure the requisite progress. As we have seen, it is the Iyengar people who have redesigned some of yoga’s most dangerous poses. Teacher training puts much emphasis on how to lessen the risks.

  My reporting on yoga injury kept producing surprises, none bigger than those involving Glenn Black. In late 2009, almost a year after meeting him, I received an email. Black said he had undergone spinal surgery. “It was a success,” he wrote. “Recovery is slow and painful. Call if you like.”

  I caught up with him at Plaza Athénée. He said the surgery had taken five hours, fusing together lumbar vertebrae three, four, and five. He would eventually be fine but was under surgeon’s orders to take it easy with his lower back. His range of motion, he added, would never be quite the same.

  He had done it to himself, Black insisted. The injury had nothing to do with trauma or aging but instead had its origins in four decades of extreme backbends and twists. To me, that recalled the wear and tear injuries of the elder yogi whose Headstands led to limb tingling, as well as Timothy McCall and his arm troubles.

  In Black’s case, it appeared that long practice had resulted in spinal stenosis—a serious condition in which the openings between vertebrae begin to narrow, compressing spinal nerves and causing severe pain. Black said he felt the tenderness start twenty years ago when he was coming out of such poses as the Plow and the Shoulder Stand. By 2007, the pain had become extreme. One surgeon said he would eventually be unable to walk. So the master teacher—a man who had been quick to speak of yoga’s dangers and to put down instructors who underwent stealthy rounds of reconstructive surgery—prepared to go under the knife.

  Black said he became quite moody as the date approached. “It was incredible,” he said. “There was a lot of turmoil.”

  I asked if the problem couldn’t have been congenital or the result of aging. No, he argued. Black said he was sure he had done it to himself.

  After recovery? “I’m going to be a decrepit old man,” he joked.

  The moral?

  “You have to set aside your ego and not become obsessive,” he replied, instantly serious. “You have to get a different perspective to see if what you’re doing is going to eventually be bad for you.”

  Black said he had recently taken that message to a conference at the Omega Institute, his feelings on the subject deepened because of the surgery. But his warnings—articulated with new vigor—seemed to fall on deaf ears. “I was a little more emphatic than usual,” he said. “My message was that ‘Asana is not a panacea or a cure-all. In fact, if you do it with ego or obsession, you’ll end up causing problems.’ A lot of people don’t like to hear that.”

  Black said the results were entirely predictable. “More people are finding out that yoga is causing injuries.”

  V

  HEALING

  Loren Fishman kept getting seduced. He studied mathematics, logic, and philosophy at the University of Michigan and Oxford and, on the side, dabbled in yoga and meditation. But he kept getting attracted to new subjects, kept wanting to learn something that would help him minister to what he considered an ailing world. In England, he stumbled upon Iyengar’s book and became entranced. The yoga was so clean, so anatomically sophisticated, so advanced compared to anything else he had encountered. The book became his bible. At the same time, Fishman kept up his wanderlust, going to India to learn Sanskrit and ancient grammar so he could look for clues to the origins of mathematics.

  One day in 1973, a friend mentioned that Iyengar lived nearby. Ah, Fishman thought—the master. The young man from Chicago was already a long way from home. But he wanted to go farther.

  Fishman knocked on Iyengar’s door and was surprised when the yogi himself answered.

  “What do you want?” Iyengar growled.

  “I want to learn your yoga.”

  “Why?”

  “Because I want to heal.”

  “That’s my great thing! Come in.”

  Fishman told the yogi of his dreams and then checked into a nearby hotel. It had a lush rooftop garden and everything an itinerant scholar could possibly want. As a teacher, Iyengar was tough and prickly. He would tease Fishman, saying the eager student had deluded himself into thinking he understood the Iyengar system.

  Finally, after a year of instruction, Iyengar ordered Fishman to go home and start teaching. Fishman did so. But he also decided to get as serious as he could about healing and went off to medical school—Rush Presbyterian St. Luke’s in Chicago, one of the oldest and most respected medical schools in America. It was founded in 1837, two years after the inauguration of the Bengal Medical College, a half a world away.

  Today a growing number of physicians study yoga after medical school. Fishman was one of the first to do so beforehand. His medical immersion when he was already an advanced student of the discipline let him see yoga through a Western lens, understanding its routines in terms of the fine distinctions of anatomy and physiology, chemistry and physics. In some respects, he was able to fuse the West’s storehouse of scientific knowledge with the inspiration of Iyengar’s visceral creativity. It was a fresh approach that bristled with possibility and seemed to offer a new way to minister to the world.

  Fishman graduated in 1979 and did a psychiatric internship at the Tufts Harvard Medical Center in Boston, eager to help troubled minds. But he found it unsatisfying and instead threw himself into rehabilitative medicine.

  The field seeks to help individuals with broken bones, torn muscles, dead nerves, injured tissues, and other physical disabilities. Its rehabilitations draw on a wide variety of tools and treatments. Standard ones include slings, braces, crutches, drugs, prostheses, walkers, physical training, therapeutic exercise, and many adjustments to the lives of patients.

  In Fishman’s case, the options include yoga.

  Few locations in the world of medical real estate are classier than 1009 Park Avenue in New York City, between Eighty-Fourth and Eighty-Fifth. It has a large but discreet awning and the usual glint of polished brass. The old building is as elegant as any on the Upper East Side. The office sits amid a constellation of physician specialists up and down the wide boulevard and across the street from the tall spire and Tiffany glass of the Park Avenue Christian Church, a neighborhood icon. The Plaza Athénée lies twenty blocks south.

  Inside, nothing suggests the office is special. It has the usual art and magazines. The main hint of individuality lies behind the receptionist—a large shelf of Fishman’s books on yoga therapy. They discuss how to treat everything from multiple sclerosis to sciatica, the condition in which irritation of the sciatic nerve causes pain to radiate through the buttocks and down the leg.

  I learned of Fishman while looking for ways to strengthen my back. His book Relief Is in the Stretch: End Back Pain Through Yoga prescribed what seemed to be a sensible regime of postures. I especially liked his explanation for what stretching did. He told of a hidden interplay between two kinds of sense organs woven into the body’s tendons and muscles. As a muscle stretched, he wrote, the two systems sent conflicting signals. Contraction was stronger than relaxation, so the muscle stayed tense. If the stretch continued, however, that signal began to diminish of its own accord and the relaxation impulse started to dominate. The transition took time, Fishman wrote. It started as the stretch continued from fifteen to thirty seconds, and the relaxation signal grew to dominate in less than two minutes.

  That mechanism, Fishman wrote, is why students of yoga should hold poses patiently—at a minimum, fifteen seconds to two minutes. Only then can the muscle relax enough to stretch farther. He said the lengthening can dramatically help victims of back pain. It can increase the ran
ge of normal motion, relaxing the spinal regions and leaving them more supple, flexible, and resilient. And that in turn can help avoid conditions that lead to muscle spasm—the sudden, involuntary contraction of muscles, sometimes accompanied by great pain.

  I enjoyed not only Fishman’s clear writing but also his earthiness. Many yoga books use fashion models to illustrate the poses. Fishman, lithe and limber, often modeled them himself.

  He appeared in the reception area, saw a patient, and gave her a hug and a few encouraging words. He was short and wiry, a bundle of energy, his smile quick. He wore a pale-blue shirt in a checkered pattern and a discretely colorful bow tie.

  We went into his office and he spread out trays of carryout sushi. The wall behind his desk was cluttered with the usual diplomas as well as a large photograph of Iyengar. The famous yogi sat in a Full Lotus, his head high and eyes open, a picture of pride and vitality. Nearby photos also showed two grown children in graduation caps and gowns. From my research, I knew Fishman had achieved quite a bit in his career. In addition to treating patients, he held a clinical professorship at the Columbia College of Physicians and Surgeons, the medical arm of Columbia University. He had published more than a hundred papers and articles. At one point, Fishman led the New York Society of Physical Medicine and Rehabilitation, serving as its president. His thriving practice, Manhattan Physical Medicine and Rehabilitation, employed physicians at four offices around the city—on Park Avenue, on the Upper West Side, in Queens, and on City Island. He also served as treasurer of the Manhattan Institute for Cancer Research, a charity.