1. Roessingh Research and Development, Enschede, The Netherlands
2. Roessingh Centre for Rehabilitation, Enschede, The Netherlands
3. Faculty of Electrical Engineering, Mathematics and Computer Science, Department of Biomedical Signals and Systems, Technical Medical Centre, University of Twente, Enschede, The Netherlands
4. Faculty of Engineering Technology, Department of Biomechanical Engineering, Technical Medical Centre, University of Twente, Enschede, The Netherlands