Arnold G. Nelson, PhD, is a professor in the School of Kinesiology at Louisiana State University. A leading researcher on flexibility, he is considered one of the top authorities on the effect of stretching on muscle performance. Nelson is a fellow of the American College of Sports Medicine and earned his PhD in muscle physiology from the University of Texas at Austin. He resides in Baton Rouge, Louisiana.
Jouko Kokkonen, PhD, is a professor in exercise science at Brigham Young University in Hawaii. For more than two decades he has taught anatomy, kinesiology, exercise physiology, and athletic conditioning, and for more than three decades he has coached track and field. Kokkonen's research has focused on the acute and chronic effects of stretching. He earned his PhD in exercise physiology from Brigham Young University and now resides in Laie, Hawaii, with his wife, Ruthanne.