Reduction of arm fatigue and discomfort using a novel steering wheel design

Driver fatigue is one of the major causes of road traffic accidents. For most of the time spent driving, the driver is required to maneuver the steering wheel with kinematically constrained arm movements. Repetition of such arm motions leads to muscle fatigue or even to neuromuscular injuries. To alleviate this problem with conventional steering wheel designs, a more user-friendly design is necessary. To help reduce the driver's arm fatigue and discomfort, this study introduces a novel steering wheel design by taking into account comfortable ranges of motion of the wrist joint. The steering wheel design allows a natural twisting motion by adding an extra degree-of-freedom to the driver's steering motion. In this study, arm fatigue and discomfort from repetitive steering motion was evaluated based on electromyogram and joint motion analyses. The data was collected from 10 subjects while using a driving simulator equipped with two types of steering wheels: a conventional steering wheel and the twisting steering wheel presented in this study. Experimental results show that the driver's arm fatigue and discomfort can be effectively reduced by incorporating an extra degree-of-freedom to the driver's steering motion.