Abstract - The effect of seat position on wheelchair propulsion biomechanics

Brian R. Kotajarvi, MS, PT; Michelle B. Sabick, PhD; Kai-Nan An, PhD; Kristin D. Zhao, MA; Kenton R. Kaufman, PhD; Jeffrey R. Basford, MD, PhD

Orthopedic Biomechanics Laboratory, Mayo Clinic, Rochester, MN; Motion Analysis Laboratory, Mayo Clinic,
Rochester, MN; Center for OrthopaEdic and Biomechanics Research, Department of Mechanical Engineering, Boise State University, Boise, ID; Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN

Abstract — This study examined the effect of seat position on handrim biomechanics. Thirteen experienced users propelled a wheelchair over a smooth level floor at a self-selected speed. Kinetic and temporal-distance data were collected with the use of an instrumented rim and a motion analysis system. A custom-designed axle was used to change the seat position. We used repeated measures analysis of variance to evaluate if differences existed in the temporal-distance and kinetic data with change in seat position. Results showed that a shorter distance between the axle and shoulder (low seat height) improved the push time and push angle temporal variables (p < 0.0001). Tangential force output did not change with seat position. Axial and radial forces were highest in the lowest seat position (p < 0.001). Propulsion efficiency as measured by the fraction of effective force did not significantly change with seat position.

Key words: biomechanics, forces, moments, propulsion, seat position, wheelchair.

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Last Reviewed or Updated Wednesday, June 29, 2005 3:38 PM