1 Division of Applied Mechanics, Department of Mechanical Engineering, Polytechnique Montréal, Canada.
2 Julius Wolff Institut, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany. Electronic address: hendrik.schmidt@charite.de.
3 Department of Human Movement Sciences, Vrije Universiteit, Amsterdam Movement Sciences, Amsterdam, The Netherlands.