Kevin M. Beck has been a runner since 1984 and is currently a senior writer for Running Times magazine.

Beck has served as a distance running coach at various levels and is coached by two-time U.S. Olympic marathoner Pete Pfitzinger. He also helped coordinate a research study on exercise and diabetes at the University of California at San Francisco, where he was a diabetes researcher and exercise technician for the Mount Zion Medical Center.

He has written a book called, "Run Strong". In part of it he talks about Perfecting Running Form. With permission of Human Kinetics, I quote part of it here.

"As a physical therapist, I am often asked how the body should look while running. There are many biomechanical interpretations of proper running form. Most physical therapists’ stand is that an athlete’s individual flexibility, strength, and joint mobility define his or her form, so there is no one correct answer; however, a runner’s knowledge of what constitutes basic proper form is important.