1. Department Rehabilitation Medicine and Research Institute MOVE, VU University Medical Center Amsterdam, The Netherlands, Department Rehabilitation Medicine, Rudolf Magnus Institute of NeuroScience, University Medical Center Utrecht, The Netherlands,
2. Research Bureau, Isala Klinieken Zwolle, The Netherlands
3. Mechanical Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, Department of Neurology and Neuroscience, Burke Institute of Medical Research, Weill Medical College, Cornell University, White Plains, New York, Department of Neurology, University of Maryland, School of Medicine, Baltimore, Maryland