1. Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts.
2. Departments of Pediatrics and Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
3. Department of Psychology, Faculty of Kinesiology, Alberta Children's Hospital Research Institute, and Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
4. Division of Emergency Medicine, Sports Medicine and Performance Center, Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
5. Division of Emergency Medicine, Children's National Health System, Washington, District of Columbia.
6. Department of Pediatrics, University of Texas Southwestern Medical School, Dallas, Texas.
7. Department of Psychology, University of Montréal and Ste-Justine Research Center, Montréal, Canada.
8. Section of Pediatric Emergency Medicine, University of Manitoba, Children's Hospital of Winnipeg, Winnipeg, Manitoba, Canada.
9. UCSF School of Medicine, Division of Pediatric Emergency Medicine, San Francisco, California.
10. Division of Pediatric Emergency Medicine, Department of Pediatrics, Montréal Children's Hospital, McGill University Health Centre, Montréal, Quebec, Canada.
11. Department of Pediatrics, University of Alberta and Stollery Children's Hospital, Edmonton, Alberta, Canada.
12. Children's Research Institute, Division of Emergency Medicine, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.
13. Department of Surgery and Pediatrics, Section of Neurosurgery, University of Manitoba, Pan Am Concussion Program, Winnipeg, Manitoba, Canada.
14. Stephen B. Freedman Sections of Pediatric Emergency Medicine and Gastroenterology, Department of Pediatrics, Alberta Children's Hospital, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
15. School of Physical and Occupational Therapy, McGill University; Trauma Programs, Montréal Children's Hospital, McGill University Health Center, Montréal, Quebec, Canada.
16. Division of Emergency Medicine, University of Montréal and Ste-Justine Research Center, Montréal, Canada.
17. UBMD Department of Orthopaedics and Sports Medicine, State University of New York at Buffalo, Buffalo, New York.
18. Departments of Emergency Medicine and Pediatrics, Concussion and Brain Performance Center, Stanford University, Stanford, California.
19. Division of Orthopaedics, Sports Medicine and Performance Center, Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
20. The Mind Research Network/LBERI and Departments of Psychology, Neurology, and Psychiatry, University of New Mexico, Albuquerque, New Mexico.
21. Department of Emergency Medicine, University of New Mexico Hospital, Albuquerque, New Mexico.
22. Pediatrics Division of Emergency Medicine, and Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York.
23. Department of Pediatrics, University of Cincinnati College of Medicine, Division of Emergency Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
24. Department of Pediatrics and Child Health, University of Manitoba, Children's Hospital of Winnipeg, Winnipeg, Manitoba, Canada.
25. Sport Injury Prevention Research Centre, Faculty of Kinesiology, Alberta Children's Hospital Research Institute, and Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
26. Department of Pediatrics and Critical Care Medicine, Children's National Medical Center, Washington, District of Columbia.
27. Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania.