[1] Univ Tubingen, Dept Sports Med, Med Clin, D-72076 Tubingen, Germany
[2] Tech Univ Chemnitz, Inst Sport Sci, Dept Human Locomot, Chemnitz, Germany
[3] Univ Tubingen, Dept Prosthodont, Sect Med Mat & Technol, D-72076 Tubingen, Germany
[4] St Hubertus Clin, Bad Wiessee, Germany