[1] Northwestern Univ, Dept Psychol, Evanston, IL 60208 USA
[2] Manchester Metropolitan Univ, Inst Biophys & Clin Res Human Movement, Manchester M15 6BH, Lancs, England
[3] Univ Ghent, Dept Movement & Sports Sci, Ghent, Belgium
[4] Univ Illinois, Dept Mech Sci & Engn, Urbana, IL 61801 USA
[5] Univ Illinois, Dept Anthropol, Urbana, IL 61801 USA
[6] Univ Illinois, Dept Psychol, Urbana, IL 61801 USA