[1] Swiss Parapleg Res, CH-6207 Nottwil, Switzerland
[2] Univ Lucerne, Dept Hlth Sci & Hlth Policy, Luzern, Switzerland
[3] Univ Bern, Inst Surg Technol & Biomech, Bern, Switzerland
[4] Cantonal Hosp Lucerne, Luzern, Switzerland
[5] Swiss Parapleg Ctr, Nottwil, Switzerland