[1] Craig Hosp, Res Dept, Englewood, CO 80113 USA
[2] Rehabil Hosp Indiana, Indianapolis, IN USA
[3] Natl Ctr Injury Prevent & Control, Traumat Brain Injury Team, Hlth Syst & Trauma Syst Branch, Div Unintent Injury Prevent,Ctr Dis Control & Pre, Atlanta, GA USA
[4] Ohio State Univ, Dept Phys Med & Rehabil, Columbus, OH 43210 USA
[5] US DOE, Natl Inst Disabil & Rehabil Res, Washington, DC 20585 USA