Anthropometry of Wheeled Mobility Project: Final Report

4.1 Introduction

The research demonstrated that there is a need to revise the standards for wheeled mobility access to reflect the body structure and functional abilities of this population and the devices they use today. The U.S. standards are in greater need of change but the basis for many of the changes previously made to the standards in Canada, the U.K. and Australia can also be questioned in light of the research findings. Findings must be evaluated very carefully when used to make changes to standards. In particular, the impact of the methods used in research on findings needs to be studied in depth. Yet, the consistency of trends across the various research studies is quite good, given the wide variety of methods used.

One obvious example of the need to revise standards is that WhMD users who require the highest knee clearances cannot be accommodated without making some radical changes to the design of counters, drinking fountains and other design features where knee and toe clearance is provided specifically to provide accessibility. Policy makers have to make a decision about who should be accommodated by knee and toe clearances or identify alternative solutions like providing side access as well as front access or at least one fully accessible unit in a building or department. The results clearly provide evidence that adjustable and adaptable counters are a valuable design strategy. They suggest that more emphasis should be placed on adjustability and that the range of adjustment should be fairly large.

As a second example, the reach limits also require some significant rethinking. The idea that a control or operable hardware located on a plane in front of the user can be accessible with a forward reach, regardless of the height, is not substantiated by this research. Knee and toe clearance must be provided under the plane of the device so that WhMD users can get closer to their target in order to provide an accessible forward reach. The safety problems we noted for low side reach questions the use of low side reach limits in accessibility standards. This reach limit should be used to identify the low range of safe reach but not to specify the location of all outlets or other devices. The result would be that outlets and other devices would all be so high that they would be dysfunctional. As an alternative, perhaps one outlet in a room or a work station area could be required to be within the safe reach range.

A third example is that the reference WhMD that has been used as the basis for standards, as depicted in the U.S. ADA-ABA, AS1428 and BS8300:2001 are manual wheelchairs. The Canadian standard, however, includes illustrations and data on scooters and power wheelchairs. This information can be very valuable to designers who are seeking to ensure full accessibility beyond minimum required levels and should be included in all accessibility standards. Designers could benefit from more information on device size to plan spaces like storage areas for wheelchairs, the design of counter edges in relationship to armrests, spaces, elements not explicitly covered by standards and new products. Additional illustrations and data are needed to convey the diversity in the devices and their occupants, especially other types of WhMDs.

To provide realistic guidance for designers, information on wheeled mobility dimensions should include occupied sizes as well as device size; both in percentile form, and also include accessories as they are used in everyday life. Occupied device sizes are clearly preferable and more useful for designers than unoccupied sizes but it is not uniformly provided in the standards. For example, the U.S. standards are inconsistent, showing occupied length but unoccupied width. Although data on device sizes is available from manufacturers, it does not include actual dimensions as set up for individuals nor does it provide data on added equipment like seating systems, cushions, control boxes, ventilators, carrying baskets and other accessories. The studies reviewed for our comparative analysis did not always include accessories as part of their dimensions and measurements (e.g. Stait et al., 2000; Hitchcock et al., 2006). A more comprehensive list of key findings can be found later in this section.