1. M Schenkman, PT, PhD, is Professor and Director, Physical Therapy Program, Department of Physical Medicine and Rehabilitation, and Assistant Dean for Allied Health, University of Colorado at Denver and Health Sciences Center, 4200 E Ninth Ave, Mailstop C-244, Denver, CO 80262-0244 (USA)
2. D Hall, MD, is Assistant Professor and Director, Movement Disorders Program, Department of Neurology, University of Colorado at Denver and Health Sciences Center
3. R Kumar, MD, FRCPC, is Medical Director, Movement Disorders Center, Colorado Neurological Institute, Englewood, Colo
4. WM Kohrt, PhD, is Professor of Medicine, Division of Geriatric Medicine, University of Colorado at Denver and Health Sciences Center