Muscle Fatigue Due to Steering Wheel Vibrations: An Analysis of the Influence of Steering Wheel Dynamics

We conducted an experiment in our fixed-base driving simulator to determine whether participants experienced arm muscle fatigue during three, one-hour driving sessions. Participants experienced different rotational vibrations on the steering wheel, each representative of a different kind of steering system. Our main hypothesis was that a ´Conventional´ steering system would result in more muscle fatigue during prolonged driving than a ´Steer By Wire´ steering system. The results of our experiment confirmed the hypothesis for the subjectively experienced muscle fatigue of the arms. We conclude that the subjective results could be related to the larger pool of additional motor units available for recruitment as time progresses during the driving task. Hence, the lower forces and the smaller vibrations of the ´Steer By Wire´ system allowed for longer exposure to the steering vibrations compared to a ´Conventional´ steering system before ´saturation´ of the motor unit recruitment set in and objective muscle fatigue could be observed.