David Zemach-Bersin and Mark Reese, Ph.D., are co-founders of Sensory Motor Learning Systems and creators of the Relaxercise system. They present workshops and lead specialized training programs for health professionals and businesses throughout the world. David Zemach-Bersin is former president of the Feldenkrais Guild of North America. He and his wife Kaethe, and three daughters live in Berkeley, California, where he teaches and conducts a private practice. Dr. Reese has published, numerous articles on health and psychology. He and his wife Donna, and two children live in San Diego, California, where he conducts a private practice in the Feldenkrais Method. Kaethe Zemach-Bersin is the… designer, illustrator, and co-author of Relaxercise. She lives in Berkeley, California, with her husband and daughters.