Most of yoga's devotees feel that the putative rewards of the exercises are worth the effort. Others may get something less than nirvana for their troubles. Dr. Joseph Chusid, a neurologist, told the A.M.A. Journal that sitting on the heels can damage the lower leg's peroneal nerve and lead to a complaint that he calls yoga foot drop.
This condition came to Chusid's attention when he was called on to treat a 22-year-old college student who had been experiencing increasing difficulty walking, running and climbing stairs. An examination failed to uncover the origin of the student's inability to control a drooping tendency...