Empirical analysis on the effect of design variables of automotive seat lumbar support on the initial sitting discomfort

An empirical analysis was performed in order to examine whether the height of the lumbar support installed on the driver’s seat in a vehicle makes a difference to the initial discomfort when sitting, and among the design variables of the seat lumbar support, which one is the main variable that affects the initial discomfort most when sitting. The subjects who participated in this study were 50^th percentile male in their 30s and 40s from Korea and America, had driving experience, and had not experienced any back pain in the last 12 months. In order to figure out the level of discomfort felt by a driver depending on the movement or the shapes of the lumbar support, subjective sensibility evaluation was conducted and sitting body pressure was measured, and the change of lumbar spine angle was observed using X-ray image. Based on the results, design variables that affect the initial discomfort when sitting on a car seat and the correlation among these design variables were verified through statistical significance testing. The empirical analysis suggested that, among design variables of car seat lumbar support, the degree of prominence is the main variable that affects the initial discomfort when sitting for both Koreans and Americans, while the height and support width have very little to do with it.