EVALUATING MOVEMENT CONSISTENCY IN WHEELCHAIR PROPULSION USING FLOQUET MULTIPLIERS AND QUATERNIONS

Abstract

Wheelchair users may develop repetitive stress injuries that are associated with the wheelchair-stroke. Evaluating if a stroke pattern is consistent may reveal the existence of a possible injury. However, there is no standardized method to evaluate the stability of the wheelchair-stroke. The purpose of this paper was to develop a method to measure movement consistency during manual wheelchair propulsion without the need of normreferenced tests. The method is based (a) on the Floquet theory, (b) on Poincaré, and (c) on quaternion transformations. The method was evaluated with experimental data and the results showed that the method is sensitive enough to identify instabilities in the wheelchair stroke cycle. Furthermore, the method can be generalized to study other aspects of human motor control.