Changes in inertia and effect on turning effort across different wheelchair configurations

This article and any supplementary material should be cited as follows: Caspall JJ, Seligsohn E, Dao PV, Sprigle S. Changes in inertia and effect on turning effort across different wheelchair configurations. J Rehabil Res Dev. 2013;50(10):1353–62. http://dx.doi.org/10.1682/JRRD.2012.12.0219

Slideshow ProjectDOI:10.1682/JRRD.2012.12.0219JSP

Changes in inertia and effect on turning effort across different wheelchair

configurations

Jayme J. Caspall, MS; Erin Seligsohn; Phuc V. Dao, MS; Stephen Sprigle, PhD, PT



• Aim– Measure changes in inertial reactance or wheelchair inertia

due to configuration changes in adjustable manual wheelchairs.

– Relate inertial changes to differences in torque required to overcome caster scrub and accelerate wheelchairs during turning.

• Relevance– When executing turning maneuvers, manual wheelchair

users must overcome rotational inertia of wheelchair system.



Method

• Measured inertias of various configurations of ultralightweight wheelchair.

• Compared:– Adjustments in axle position.– Changes in wheel and tire type.– Addition of several accessories.



Results• Configuration with highest rotational inertia (solid tires,

mag wheels with rearward axle) exceeded configuration with lowest (pneumatic tires, spoke wheels with forward axle) by 28%.

• Greater inertia requires increased torque to accelerate wheelchair during turning.

• At representative maximum acceleration, reactive torque was 11.7 to 15.0 N-m across wheelchair configurations. – At higher accelerations, torques exceeded that required to

overcome caster scrub during turning.



Conclusion• Results indicate that:– Wheelchair’s rotational inertia can significantly

influence torque required during turning.– This influence will affect active users who turn at high

speeds.

• Categorizing wheelchairs using both mass and rotational inertia would better represent differences in effort during wheelchair maneuvers.

Changes in inertia and effect on turning effort across different wheelchair configurations

Documents

Transcript of Changes in inertia and effect on turning effort across different wheelchair configurations