Construction of the simulation model of pushing motion in wheelchair tennis

Abstract

Since wheelchair tennis players sprint a short distance frequently, it is necessary to evaluate the pushing motion and the propulsion performance of the wheelchair in the pushing motion. In this study, the multibody dynamics simulation model of a human and a wheelchair was constructed for the evaluation without any experiments. The human and wheelchair were defined as rigid body links. In the human model, eight joints (waist, thorax, right and left shoulders, right and left elbows and right and left wrists) had one or three degrees-of-freedom and the other joints had no degree-of-freedom. The wheels and casters in the wheelchair model had one degree-of-freedom to rotate so that the wheelchair ran straight. In order to represent sitting, a constraint force was defined between a point in the pelvis and a point in the seat. In order to represent grasping the handrim, virtual spring and damper forces were defined between a point in the hand and a point in the handrim. The contact force between the wheels and the ground was defined by using an existing tyre model. The pushing motion by a skilled player was measured and put into the model. A simulation in which the wheelchair ran on the ground was conducted. As a result, it was confirmed that the wheelchair propelled forward with acceleration.