1. Center for Rehabilitation Research, Texas Tech University Health Sciences Center, Lubbock, Texas, USA.
2. University Hospital of Orthopaedics and Trauma Surgery Pius-Hospital, Medical Campus University of Oldenburg, Oldenburg, Germany.
3. Tufts University School of Medicine, Medford, MA, USA.
4. Boma, Physical Therapy Outpatient Clinic, Mariazeller Straße 30, 8605 Kapfenberg, Styria, Austria.