1. P.C. Siemonsma, PT, PhD, Amsterdam Rehabilitation Research Center–Reade, Amsterdam, the Netherlands. Mailing address: TNO Life Style, Elderly and Chronically Ill, PO Box 2215, 2301 CE Leiden, the Netherlands.
2. I. Stuive, PhD, Centre for Rehabilitation, University Medical Centre Groningen, University of Groningen, Groningen, the Netherlands.
3. L.D. Roorda, PhD, MD, Amsterdam Rehabilitation Research Center–Reade.
4. J.A. Vollebregt, PhD, MD, Amsterdam Rehabilitation Research Center–Reade.
5. M.F. Walker, OT, PhD, Division of Rehabilitation and Aging, University of Nottingham, Nottingham, United Kingdom.
6. G.J. Lankhorst, PhD, MD, Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam, the Netherlands.
7. A.T. Lettinga, PT, PhD, Centre for Rehabilitation, University Medical Centre Groningen, University of Groningen.