title: How does lever length and the position of its axis of rotation influence human performance during lever wheelchair propulsion?
abstract: The purpose of this study was to investigate empirically how lever length and its axis of rotation position influences human performance during lever wheelchair propulsion. In order to fulfill this goal, a dedicated test stand allowing easy implementation of various lever positions was created. In the experiment, 10 young, healthy, male subjects performed 8 tests consisting of propulsion work with levers of different lengths and lever axis of rotation positions. During tests heart rate, oxygen consumption and EMG assessment of 6 muscles was carried out. Measurements of power output on the test stand were done as well. Together with oxygen consumption analysis, this allowed calculation of human work efficiency. The results show significant (p<0.05 and p<0.001) differences between lever configurations when comparing various parameters values. From the carried out experiments, the authors conclude that levers' length and their axis of rotation position significantly influence human performance during lever wheelchair propulsion. For the examined subjects, placing the levers' axis of rotation close behind the back wheels axis of rotation offered advantageous work conditions.
authors.affiliation: Faculty of Transport, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Fiok
authors.affiliation: Faculty of Physical Education, Józef Piłsudski University of Physical Education, Warsaw., ul. Marymoncka 34, 00-968 Warszawa, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Mróz
mesh_terms: D000328:Adult; D006339:Heart Rate; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D012399:Rotation; D014910:Wheelchairs / Q000009:adverse effects / Q000592:standards*
keywords: EMG; Efficiency; Heart rate; Human work; Lever; Lever axis of rotation; Oxygen consumption; Wheelchair