1. Duke Clinical Research Institute, and Vice Chair of Clinical Research, Orthopaedic Surgery, Duke University, Durham, North Carolina. He is a Catherine Worthingham Fellow of the American Physical Therapy Association
2. National Center for Injury Prevention and Control, Centers for Disease Control and Prevention. Dr Greenspan's contribution as guest co-editor was done as a personal outside activity. The content of this editorial is that of the authors and does not necessarily represent the official position of the Centers for Disease Control and Prevention