Theoretical Comparison of the Resultant Braking Force Applied on a Manual Wheelchair within a Propulsion Cycle on the Field and on Laboratory Ergometers

摘要

The aim of this study was (a) to quantify the resultant braking force applied on a manual wheelchair during a foil propulsion cycle on the field, while taking into account the ground normal reaction and its distribution between front and rear wheels, and (b) to compare the results obtained on the field with those obtained by simulation on a roller ergometer and on a wheelchair simulator. Field results showed that the braking force varied across the propulsion cycle: it was minimal just before the subject gripped the handrims and maximal at the beginning of the free-wheeling phase. On the roller ergometer, the braking force applied on rear wheels varied in an opposite way than on the field, whereas on the simulator, it remained logically constant. These results showed that laboratory ergometers are not able to reproduce the reality of braking forces applied during field propulsion and that they should be modified consequently.