The Science of Yoga

reinflate. Immediately, the symptoms of labored breathing went away. The woman, after a week of recovery, underwent a procedure for removal of the tube.
    In 2004, the doctorsfrom the Berkshire Medical Center documented the unusual case in Chest , the respected journal of the American College of Chest Physicians. They noted that an imaging scan of the woman’s chest had revealed no lung pathologies that might account for the pneumothorax, and concluded that the rupture was a direct result of yoga breathing. The case was without known precedent, they said, and showed that “adverse side effects can occur when one pushes the body to physiologic extremes.”
    In this case, the yoga community took notice and reacted. The days of denial and evasion were ending rapidly as the once-secretive topic of yoga injuries increasingly went public.
    A yoga teacher and a medical doctor who had advised the teacher in developing a program for people with breathing disorders wrote a joint letter to Chest. The two, based in Sacramento, California, agreed that the rapid breathing exercise “most probably induced the pneumothorax” and backed the report’s cautionary advice. But they said its warning about pushing the body to physiologic extremes created a false impression that “appears to unjustly blame all yoga techniques. This is not appropriate for a discipline that has generally been practiced safely for not hundreds, but thousands of years.”
    The yoga teacher—Vijai P. Sharma—took to the pages of the International Journal of Yoga Therapy to discuss the case and argue for the relative safety of Kapalbhati and other yoga breathing exercises. But his argument was heavy with caveats. He drew a distinction between fast and slow breathing, saying yoga’s quick styles posed greater risk. Fast breathing, he wrote, “may reinforce or worsen preexisting structural or functional problems.” Finally, Sharma enumerated a long list of safety guidelines and heightened risk factors (diabetes, chronic hypertension, persistent head pain) that made fast breathing seem like it was generally a risky venture.
    Unless students exercise “out-of-the-ordinary patience and self-control,” Sharma warned, “rapid breathing techniques such as Kapalbhati and Bhastrika are likely to be performed incorrectly and prove harmful in the long run.”
    Yet another case that came to light featured an aging yogi. The man had done yoga since his thirties and was sixty-three when the trouble hit. His daily practice includedthe Headstand. He suffered no neck or back problems until one day he began to feel tingling and numbness in his fingers and toes. Over a few months, his legs and arms grew increasingly weak, and he began to experience the urge to urinate frequently.
    His doctors saw the symptoms as classics of quadriplegia—limb weakness due to an injured spinal cord. Diagnostic imaging showed a region of disk compression and displacement between the C3 and C6 vertebrae. Health professionals, they wrote in their 2007 report, “need to be aware of this potentially serious complication of a relatively innocuous exercise.”
    In my thirties, I somehow managed to rupture a disk in my lower back. The cause seemed to be the repeated shocks of running on pavement rather than yoga. I looked into surgery, but found I could prevent bouts of pain with a selection of yoga postures and abdominal exercises.
    In 2007, I experienced my own “serious complication” while studying with Robin in Pennsylvania. It happened as I did the Extended Side Angle pose, or Utthita Parsvakonasana. That was the posture that Krishnamacharya praised as a cure for many diseases. I was coming out of the pose and chatting with my partner—instead of paying attention to what I was doing—when my back gave way.
    Blinding pain forced me to ignore everything but the explosion of fire. It was excruciating. My legs failed and the room vanished in tears. My body slammed into a wall.
    Recovery took weeks. But the humbling experience gave me a deeper appreciation for yoga safety.
    The redesign of poses by the yoga community ranged from tweaks to wholesale rearrangements. More drastic, some authorities called for the removal of risky postures from the Hatha corpus entirely or gave them warnings harsh enough to serve as de facto prohibitions, as with Kapalbhati and Bhastrika. The wave of new precautions was different from when medical outsiders drew up lists of X-Rated Exercises. It featured some