1. The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA
2. Harvard Medical School, Boston, Massachusetts, USA
3. Division of Sports Medicine, Department of Orthopaedics, Boston Children’s Hospital, Boston, Massachusetts, USA
4. Division of Emergency Medicine, Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
5. Princeton University, Princeton, New Jersey, USA
6. Harvard University, Cambridge, Massachusetts, USA