Preferred Settings in Chair Adjustments

Abstract

Thirty eight subjects participated in a study to evaluate preferred (comfortable) settings of adjustable chairs including seat height, seat pan angle and back rest angle. An instrumented hydraulic chair was used. The chair was set in one of eight possible extreme position, with each chair parameters at either a high or low value. Subjects then adjusted all three parameters. A full factorial experiment with 5 factors was performed: the three adjustability parameters set at either high or low, gender and replication. Three independent variables were used: preferred seat height, back rest angle and seat pan angle. For the three ANOVA's and across two experiments, 33 statistically significant results were obtained. The initial setting of a parameter (high or low) consistently produced a significant effect in the choice of the preferred setting for the same parameter. The findings imply that there is a range of acceptable settings: for seat height about 1 in. and for the back support angle and seat back angle about 4 degrees.