Anthropometry of Wheeled Mobility Project: Final Report

3.3.4 Clear Floor Length

The mean value of clear floor length for our study (1250 mm or 49 in.) is above the clear floor length provided in the U.S. standards (1220 mm or 48 in.). Australian and U.K. have also recently increased the clear floor length standards (Figure 3‒4). The U.K. requirements for clear floor length exceed the U.S. by 130 mm (5 in.). The results of our study and other anthropometric studies support larger lengths to accommodate the vast majority of occupied WhMD lengths. The largest occupied lengths reported in all the anthropometric studies exceed the current standards, even the U.K. BS8300 standard of 1350 mm (53 in.). However, the results show that the 95th percentile values of occupied length are between 1250 mm. (49 in.) and 1480 mm (58 in.).

The difference between the maximum length in the UDI and Seeger studies and the others is so great that they are probably due to the presence of unusually large people and/or devices, or measurement error. The maximum length (occupied) recorded in the UDI study, for example, was over 2000 mm (6 ft.- 8 in.)! In the case of Seeger et al.’s work, we know that most of the sample was recruited from institutions and many may have had extended foot-rests or reclined backs on their chairs. No information was provided in the reports to assess whether individuals in either study could be considered outliers. For example, since the other studies together included over 1200 individuals and no other study reported a device as long as 2000 mm (78 in.), such a large value is likely a measurement error or a very rare occurrence. In fact, by coincidence, we met an individual who served as an advisor and participant in the UDI research. She recalled that there was one individual who had a “trailer” attached to her wheelchair that carried ventilator equipment which would not be required anymore due to advances in technology.

* Indicates data plotted in the graph.

Figure 3-4. Clear floor length (occupied length): research findings versus the standards.