Abstract
Neutral posture which can be observed in zero-gravity environment seems to be low-fatigue posture which minimizes biomechanical loads. It needs to recline seatback backward so that the neutral posture can be realized at seating condition in gravity field. The purpose of this study is to develop an ideal driving posture which is fitted with ordinary used seatback degree of freedom and a new seat which supports upper-body so that it may become the ideal driving posture for reduction of physical fatigue during long term driving. This seat was tested by subjective evaluation and physiological indices measurement in long term driving. The results showed the new seat reduced physical fatigue compared with conventional seat.
