[1] Seattle Childrens Res Inst, Ctr Child Hlth Behav & Dev, Seattle, WA USA
[2] Univ Washington, Dept Pediat, 2001 8th Ave,Ste 400, Seattle, WA 98121 USA
[3] Harborview Injury Prevent & Res Ctr, Seattle, WA USA
[4] Univ Washington, Dept Family Med, Seattle, WA 98121 USA
[5] Univ Washington, Dept Orthopaed & Sports Med, Seattle, WA 98121 USA
[6] Univ Washington, Dept Neurol Surg, Seattle, WA 98121 USA
[7] Univ Washington, Dept Rehabil Med, Seattle, WA 98121 USA
[8] Univ Michigan, Sch Kinesiol, Ann Arbor, MI 48109 USA
[9] Univ Michigan, Dept Neurol, Ann Arbor, MI USA
[10] Univ Michigan, Dept Phys Med & Rehabil, Ann Arbor, MI USA
[11] Univ Penn, Perelman Sch Med, Dept Pediat, Philadelphia, PA 19104 USA
[12] George Washington Univ, Sch Med, Washington, DC USA
[13] Childrens Natl Hlth Syst, Washington, DC USA
[14] Princeton Univ, Princeton, NJ 08544 USA
[15] Univ N Carolina, Dept Exercise & Sport Sci, Chapel Hill, NC 27515 USA