To better understand and represent the seated human posterior back, buttocks, and thigh contours, three groups of human subjects (5th percentile small females, 50th percentile mid-sized males, and 95th percentile large males) were measured in a specially designed contour chair within typical automotive interior environment. The postures were acquired by a human motion measurement system.

The data were analyzed, and then representative seated mid-sized male posterior back, buttocks, and thigh contours were developed for both physical hardware and computer program software for automotive seating design and validation.

To explore the relations among contours of people with different anthropometric dimensions and the possibility to relate the contours of different anthropometric groups of people, a method was developed to scale the mid-sized male contours to large male or small female subjects’ contours. Potentially it could be used to generate the contours for people in different groups other than small female and large male. For the first time, the scaling methodology of scaling contours of mid-sized male to small female or large male was verified by experimental data. The coefficient of correlation analysis produced very high agreements between the scaled and measured data of the contours.

Both the hardware and software from this research are being utilized in the automotive seating industries. The data collected in this research are having significant influences on the seating design and validation.