1. Otto Bock Healthcare Products, Vienna, Austria
2. Fraunhofer Institute for Biomedical Engineering (IBMT), Sankt Ingbert, Germany
3. Hamburg University of Technology, Hamburg, Germany
4. Georg August University, Göttingen, Germany
5. Center for Spinal Cord Injuries at Werner-Wicker-Hospital, Bad Wildungen, Germany
6. Vienna University of Technology, Vienna, Austria