1. Department of Orthopedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
2. Investigation performed at University of Pittsburgh, Pittsburgh, Pennsylvania, USA
3. Duquesne University, Pittsburgh, Pennsylvania, USA
4. Indiana University, Bloomington, Indiana, USA
5. University of Arkansas, Fayetteville, Arkansas, USA
6. University of Florida, Gainesville, Florida, USA
7. Humboldt State University, Arcata, California, USA
8. University of Michigan, Ann Arbor, Michigan, USA
9. Indiana University, Indianapolis, Indiana, USA
10. Medical College of Wisconsin, Milwaukee, Wisconsin, USA
11. Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
12. University of Wisconsin, Madison, Wisconsin, USA
13. University of Delaware, Newark, Delaware, USA
14. University of North Carolina, Chapel Hill, North Carolina, USA
15. Wake Forest University, Winston-Salem, North Carolina, USA