1. K.R. Archer, PT, PhD, DPT, is Assistant Professor, Department of Orthopaedics and Rehabilitation, Vanderbilt University Medical Center, Medical Center East–South Tower, Ste 4200, Nashville, TN 37232 (USA).
2. E.J. MacKenzie, PhD, is Fred and Julie Soper Professor and Chair, Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland.
3. M.J. Bosse, MD, is Director of Clinical Research and Orthopaedic Traumatologist, Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, North Carolina.
4. A.N. Pollak, MD, is Associate Professor of Orthopaedics and Chief, Division of Orthopaedic Traumatology, R. Adams Cowley Shock Trauma Center, University of Maryland Medical Center, Baltimore, Maryland.
5. L.H. Riley III, MD, is Associate Professor and Division Chief, Spine Surgery, Department of Orthopaedic Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland.