Determining optimum seat depth using comfort and discomfort assessments

The aim of this study was to determine optimum seat depth using subjective assessments. Comfort and discomfort evaluation, as an ergonomic subjective method, was used to find the optimum seat depth. A total of 36 university students rated the comfort and discomfort of six different seat depths (including 32.0, 37.0, 42.0, 47.0 and 52.0 cm which covered the buttock–popliteal length [BPL] range as well as 40.2 cm representing the 5th percentile of the BPL) during a 90-min period using a chair evaluation checklist. The results showed that a seat depth of 40.2 cm (equivalent to the 5th percentile of the BPL) was more comfortable and caused less discomfort ratings after 90 min compared to other experimental seat depths. The findings suggest that an appropriate seat depth for the studied population can be recommended based on the 5th percentile of the BPL as an anthropometric criterion.