1. Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, Department of Exercise and Sport Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
2. Curriculum in Human Movement Science, Department of Allied Health Sciences, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
3. Injury Prevention Research Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
4. Clinical Research Unit, Emergency Services Institute, WakeMed Health and Hospitals, Raleigh, North Carolina
5. Department of Epidemiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
6. Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin