1. Center for Injury Research and Prevention, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
2. University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
3. National Center for Injury Prevention and Control, Centers for Disease Control and Prevention, Atlanta, GA, USA
4. Hasbro Children’s Hospital and Alpert Medical School of Brown University, Providence, RI, USA
5. Sport Medicine and Performance Center, The Children’s Hospital of Philadelphia, PA, USA