Measurement of wheelchair rolling resistance with a handle bar push technique.

The purpose of this study was to evaluate a technique of pushing a wheelchair at the level of the handle bars as a method for measuring rolling resistance of wheelchair-user systems under different field conditions. Under standardized conditions on a motor driven treadmill, rolling resistance was determined using a 2D strain gauge-based push technique at the level of the handle bars and a commonly used 1D strain gauge-based wheelchair drag test using an adapted push wheelchair and ISO dummy at several velocities and using different push handle heights. After verification of the method, rolling resistance of six different floor surfaces was measured with the experimental push wheelchair in a centre for rehabilitation. Using an analysis of variance for repeated measures, small but significant differences in rolling resistance were found between the drag and push tests on a motor driven treadmill. Belt velocity and push handle height significantly affected rolling resistance. In the field study in the rehabilitation centre, tiles and tarpaulin had the lowest rolling resistance, while high piled carpet had the highest values. It is concluded that the wheelchair pushing method described in this study is usable for the determination of (relative) differences in rolling resistance of different floor materials if performed under standardized conditions and procedures, such as a stable velocity (within a small range of variation), using an ISO-dummy and a constant pushing handle bar height.