DAVID A. WINTER, PhD, is Distinguished Professor Emeritus in Kinesiology at the University of Waterloo. Prior to his appointment at Waterloo, he held appointments in surgery at the University of Manitoba, served as director of Biomedical Engineering Research at the Shriners Hospital in Winnipeg, and worked in electrical engineering at the Technical University of Nova Scotia, Halifax, and at the Royal Military College, Kingston. His many distinctions include Fellow of the Institute of Electrical and Electronic Engineers and of the Canadian Society for Biomechanics. He was the first recipient of...