Anthropometry of Wheeled Mobility Project: Final Report

3.3.2 Unoccupied Device Length

The unoccupied length of devices could be compared only between our study and the U.K. study (Stait et al., 2000). Our findings for mean, 80th percentile and 90th percentile values were somewhat larger than those of the comparison study (Figure 3‒2). This again was likely due to the larger percentage of powered wheelchairs and manual bariatric wheelchairs that were included in our study.

The unoccupied lengths of devices used for the “reference wheelchair” described in the U.S. standard equals the average value obtained from our overall sample. The mean unoccupied length for a powered wheelchair in our sample was 52 mm (2 in.) greater than the unoccupied length of the reference chair given in the standards, and the longest unoccupied length measured in our study was over 600 mm (23.6 in.) greater than the unoccupied length of the “reference wheelchair”!

There are a few reasons for the disparity in our unoccupied length data and the unoccupied length of the “reference wheelchair” currently provided in the standards. First, the available WhMD technologies of today are structurally different than those from which the standards were derived. For example, powered wheelchairs and scooters are generally longer than manual wheelchairs. Second, we measured the unoccupied length of the WhMD while it was in use; thus devices measured with elevated leg supports would be “lengthened.” Third, many of today’s mobility users attach accessories to the back of their device; we included the accessories in our length measurements.

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* Indicates data plotted in the graph.

Figure 3-2. Unoccupied WhMD length: research findings versus the U.S. standards.