A methodology to determine the optimum seat depth

Even though the seat pan carries most of the weight during sitting, the num ber of studies investigating the different aspects of the sitting area are limited. Seat depth has been based on anthropometry?; or the so-called indu stry practice. The relevance of the widely used seat depth measure is thus questionable. A methodology has been developed to evaluate the useful seat depth For a target population. The methodology is found to be reliable and valid based on both objective and subjective measurements. A chair with an "adjustable" seat depth was designed and developed for this purpose. A tota l of 30 Chinese students were tested. The objective measure was the seat ed ge protrusion when seated. Eight seat features were rated using a 5-point s cale. The results show that the seat depth`s of 30.4 and 38cm are significa ntly different, with the seat depth of 38 cm being on the "long side". In a ddition, the objective measure of seat edge protrusion indicated that a sea t depth of 31-33 cm is adequate for the South China region Chinese populati on. Based on the subjective ratings and the objective measure developed, it may be concluded that a seat depth of 31-33 cm is appropriate For the same population.