Anthropometry of Wheeled Mobility Project: Final Report

3.3.5 Seat Height

Height dimension standards for seats prescribed in the Australian, Canadian and U.S. standards were very similar (480 mm or 18.9 in., 480 mm or 18.9 in. and 485 mm or 19 in., respectively). The values in the current standards for seat height are below the means for people we measured and those in the UDI study (Figure 3‒5). This is probably due to the increasing use of positioning systems, thick cushions and the availability of a wider range of wheel sizes since the 1970’s.

Comparisons of research findings on the seat heights for power chairs and scooters showed that mean seat heights measured in the UDI study were comparable to seat heights for the power chairs and scooters of our study; however, the differences grew larger toward the higher percentiles. Further, our study findings also revealed that occupied seat heights for manual chairs were much lower than seat heights for power chairs and scooters.

The reference points used for measurement can yield quite different results for seat height. The height of the seat can be measured at the edge and at the middle, under the cushion, on top of the cushion, etc. Thus, specifying exactly how it is measured is important for comparing results. We computed the occupied seat height by measuring a point underneath an individual’s buttocks using an extension of the electromechanical probe that we slipped in from the side between the occupant and seat interface. Our results would be different compared to other measurements not made in a similar manner.

* indicates data plotted in the graph

Figure 3-5. Seat height: research findings versus the standards.