Effects of Back Postures on Driving Positions as Measured With DHMs

Abstract

Drivers use a range of back postures that affect seated positions. Standards in seat design and safety tests assume drivers sit in fully supported back postures which this investigation finds invalid for small females. Twenty-two cars and 20 utility vehicles from Europe, USA, and Asia were measured and evaluated with the ERL Digital Human Models. In these vehicles, the head restraint interferes with upright postures in small females and requires an average neck flexion that is 2.9X greater than optimal for driving positions in these DHMs. Small women’s thighs penetrate the linear elastic region of front of cushion an average of −5.7 ±5.9 mm which would require muscle contra-ctions to compress for holding the heel on the floorboard. Postural adaptations move small women into unsupported backs for driving. Consequently, improvements in vehicle and seat designs for back posture variability are needed for comfort, ergonomics, and safety.