[1] Matthew Gfeller Sport Related Traumat Brain Injur, Dept Exercise & Sport Sci, Chapel Hill, NC USA
[2] Univ N Carolina, Injury Prevent Res Ctr, Chapel Hill, NC 27599 USA
[3] Univ N Carolina, Curriculum Human Movement Sci, Div Allied Hlth Sci, Sch Med, Chapel Hill, NC 27599 USA
[4] Ctr Dis Control & Prevent, Natl Ctr Injury Prevent & Control, Div Unintent Injury Prevent, Atlanta, GA USA