1. Institute for Rehabilitation and Performance Technology, Division of Mechanical Engineering, Department of Engineering and Information Technology, Bern University of Applied Sciences, Burgdorf, Switzerland
2. Centre for Rehabilitation Engineering, School of Engineering, University of Glasgow, Glasgow, UK
3. Biomedical Engineering, University of Strathclyde, Glasgow, UK
4. Physical Therapy Program, Wayne State University, Michigan, MI, USA
5. School of Engineering, University of Glasgow, Glasgow, UK