[1] Univ Penn, Perelman Sch Med, Dept Biostat Epidemiol & Informat, Philadelphia, PA 19104 USA
[2] Univ Penn, Penn Injury Sci Ctr, Philadelphia, PA 19104 USA
[3] Univ Penn, Perelman Sch Med, Dept Pediat, Philadelphia, PA 19104 USA
[4] Childrens Hosp Philadelphia, Ctr Injury Res & Prevent, Philadelphia, PA 19104 USA
[5] Childrens Hosp Philadelphia, Sports Med & Performance Ctr, Philadelphia, PA 19104 USA
[6] SUNY Buffalo, Jacobs Sch Med & Biomed Sci, Dept Psychiat, Buffalo, NY USA
[7] SUNY Buffalo, Jacobs Sch Med & Biomed Sci, UBMD Orthopaed & Sports Med, Buffalo, NY USA