1. Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Koeln, Germany
2. Department of Diagnostic and Interventional Radiology, University of Cologne, Cologne, Germany
3. Brooks Sports Inc., Seattle, WA, United States
4. Brooks Sports, Inc., Biomechanics Laboratory, Bothell, WA, United States
5. Kinesiology, University of Massachusetts, Amherst, MA, United States