1. Interfaculty Initiative in Health Policy, Harvard University, Cambridge, Massachusetts, USA
2. Micheli Center for Sport Injury Prevention, Division of Sports Medicine, Boston Children’s Hospital, Boston, Massachusetts, USA
3. Department of Pediatrics, University of Washington, Seattle, Washington, USA
4. Center for Child Health, Behavior and Development, Seattle Children’s Research Institute, Seattle, Washington, USA
5. Harborview Injury Prevention and Research Center, Seattle, Washington, USA
6. Department of Radiology, University of Wisconsin–Madison, Madison, Wisconsin, USA
7. Chronic Traumatic Encephalopathy Center, Boston University School of Medicine, Boston, Massachusetts, USA