In recent years, research and development of competitive wheelchairs has been actively carried out in preparation for the Paralympics in our countries. The purpose of this study is to reveal the driving performance of a wheelchair for tennis depending on the height of the rear wheel caster and to improve the performance of the athlete. A tennis wheelchair generally consists of two driving wheels, two front wheel casters and one rear wheel caster, and the weight of the wheelchair is distributed on each tire and transmitted to the ground. When the height of the rear wheel caster is changed, the pressure distribution on the ground when the athlete rides on the wheel changes. The stability and propulsive force during driving were revealed by using 9-axis acceleration sensors, surface electromyography and running time data. As a result, when the rear wheel caster was in the "High" position, which relies heavily on the drive wheel weight, one drive had more thrust when going straight, and the number of drives was reduce, so the running time was faster. However, during turning, the running time was slower due to the decrease in speed immediately after turning.
