Bill Case PT, a physical therapist for over 30 years, has lectured nationally and internationally on orthopedic injuries and a published authority on exercise, injury, and injury prevention. He coauthored SPORTS PHYSICAL THERAPY and invented the diagonal rotary patterning exercise machine. Bill is also the founder and co-sponsor of Houston's Annual Senior Falls Prevention Day and has scripted and produced Keep Fit and Moving (DVD) for seniors to help prevent falls.