1. Swiss Paraplegic Research; Nottwil Switzerland
2. Institute for Surgical Technology and Biomechanics; University of Bern; Switzerland
3. Swiss Paraplegic Centre; Nottwil Switzerland
4. School of Medicine; Griffith University; Brisbane Queensland Australia
5. Cantonal Hospital of Lucerne; Lucerne Switzerland
6. Institute for Biomechanics; ETH Zurich; Switzerland