At the age of 20, a 4-ton hoist fell on Dr. Perry’s leg and only a motorcycle racing boot that he was wearing kept him from losing his leg. It took him four surgeries and six years to regain his ability to walk and run. During that time, he lost his appetite for medical school, where he had been headed, and instead sought out the field of rehabilitation at the Los Angeles College of Chiropractic (now called Southern California University...