1. K.R. Archer, PT, PhD, DPT, is Assistant Professor, Department of Orthopaedics and Rehabilitation, School of Medicine, Vanderbilt University Medical Center, Medical Center East–South Tower, Suite 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. R.C. Castillo, PhD, is Assistant Professor, Department of Health Policy and Management, Bloomberg School of Public Health, Johns Hopkins University.
4. M.J. Bosse, MD, is Director of Clinical Research and Orthopaedic Traumatologist, Department of Orthopaedic Surgery, Carolinas Medical Center, Charlotte, North Carolina.