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Logo for the Journal of Rehab R&D
Volume 42 Number 4, July/August 2005
Pages 447 —458

Abstract - A kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces

Alicia M. Koontz, PhD, RET;1-3* Rory A. Cooper, PhD;1-4 Michael L. Boninger, MD;1-4 Yusheng Yang, MA;1,4 Bradley G. Impink, BS;1-2 Lucas H. V. van der Woude, PhD3,5

1Human Engineering Research Laboratories, Department of Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA; 2Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA; 3Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA; 4Department of Physical Medicine and Rehabilitation,
University of Pittsburgh Medical Center Health System, Pittsburgh, PA; 5Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Vrije University, the Netherlands
Abstract — The objective of this study was to conduct a kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces. Eleven manual wheelchairs were fitted with a SMARTWheel and their users were asked to push on a course consisting of high- and low-pile carpet, indoor tile, interlocking concrete pavers, smooth level concrete, grass, hardwood flooring, and a sidewalk with a 5-degree grade. Peak resultant force, wheel torque, mechanical effective force, and maximum resultant force rate of rise were analyzed during start-up for each surface and normalized relative to their steady-state values on the smooth level concrete. Additional variables included peak velocity, distance traveled, and number of strokes in the first 5 s of the trial. We compared biomechanical data between surfaces using repeated-measures mixed models and paired comparisons with a Bonferroni adjustment. Applied resultant force (p = 0.0154), wheel torque (p < 0.0001), and mechanical effective force (p = 0.0047) were significantly different between surfaces. The kinetic values for grass, interlocking pavers, and ramp ascent were typically higher compared with tile, wood, smooth level concrete, and high- and low-pile carpet. Users were found to travel shorter distances up the ramp and across grass (p < 0.0025) and had a higher stroke count on the ramp (p = 0.0124). While peak velocity was not statistically different, average velocity was slower for the ramp and grass, which indicates greater wheelchair/user deceleration between strokes. The differences noted between surfaces highlight the importance of evaluating wheelchair propulsion ability over a range of surfaces.
Key words: access, biomechanics, community access, driving surfaces, manual wheelchair, propulsion forces, ramps, rolling resistance, sidewalks, standards, surface resistances, wheelchair propulsion.

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