1. Washington University School of Medicine, St. Louis, Missouri, USA.
2. Division of Physical Medicine and Rehabilitation, Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA.
3. Department of Physical Medicine and Rehabilitation, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
4. Division of Physical Medicine and Rehabilitation, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
5. Division of Public Health Sciences, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
6. Division of Adult Reconstruction and Hip Preservation, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.