Anthropometry of Wheeled Mobility Project: Final Report

3.1 Comparison of Our Sample to U.S. Population of WhMD Users

Our sample of WhMD users was younger in age, had a much higher percentage of powered wheelchair users and a somewhat larger sample of male WhMD users than the estimated U.S. population of WhMD users (Table 3‒1). As stated in the previous section, we deliberately over-sampled powered device users in order to be able to accurately describe the anthropometric characteristics of this group. The higher frequency of male WhMD users recruited for this study is not very surprising as two of our data collection sites (Buffalo and Pittsburgh) recruited some of their study participants through VA medical centers that had extremely high percentages of male patients. As a result, our overall sample, when compared to the overall population of WhMD users is likely to have lower upper extremity and torso function, and be somewhat larger (i.e., taller, longer arms, wider, etc.). As stated in the previous chapter, these sample differences can be accounted for by stratifying the data by WhMD and/or by gender, or through the use of statistical modeling methods (Paquet et al., in preparation).

In terms of the medical conditions, Kaye et al. (2000) reported orthopedic impairments of the lower extremity (17% when combined with arthritis and other polyarthritis to conform with the classification used in the current study), cerebral vascular diseases (e.g. stroke, 11%), and central nervous system disorders (8%, including multiple sclerosis and cerebral palsy) as being the most frequently reported conditions leading to the use of a WhMD in the U.S. population. The most frequently reported medical conditions in our study were found to be central nervous system disorders (32%, including multiple sclerosis and cerebral palsy), spinal cord injuries (20%), cerebral vascular diseases (16%), followed by orthopedic impairments of the lower extremity (12%). The higher prevalence of spinal cord injuries in our study sample is expected given that two of the study locations recruited substantially through local VA medical centers.

Table 3‒1. Comparison of the percentages of WhMD users by gender, device type and age based on the estimated U.S. population of non-institutionalized WhMD users (Kaye et al., 2000) and our sample of WhMD users (n=495).

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