1. Institute of Orthopaedic Research and Biomechanics, Center of Musculoskeletal Research; University of Ulm; Helmholtzstr. 14 89081 Ulm Germany
2. Department of Osteology and Biomechanics; University Medical Center Hamburg-Eppendorf; Hamburg Germany
3. Division of Pathophysiology and Process Development in Anesthesia, Department of Anesthesia; University Medical School; Ulm Germany