Print E-mail


The standards used to ensure accessibility for people who use wheeled mobility devices (WhMDs) like wheelchairs and scooters are based on research in anthropometry, the measurement of body sizes and physical abilities. The anthropometric data on WhMD users that underlies the technical requirements of the ICC/ANSI A117.1 (1998) Accessible and Usable Buildings and Facilities (ICC/ANSI) were generated from research completed from 1974 -1978 using a research sample that included about 60 individuals who used wheelchairs (see Steinfeld et al., 1979). In 1982, the U.S. Access Board developed the first Federal guidelines for facility accessibility in the U.S.  Under the Americans with Disabilities Act of 1990 (ADA), the Board continued this work, publishing the ADA Accessibility Guidelines (ADAAG) in 1991 which were updated in 2004 by the ADA and ABA Accessibility Guidelines for Buildings and Facilities (ADA-ABA Standards). The latter was adopted in place of the ADAAG by the Department of Justice in 2010.  Provisions for WhMD users in both guidelines were largely derived from the research conducted in the 1970’s (Steinfeld et al., 1979). Comments from people who use powered mobility devices indicate that increases in space and maneuvering requirements and decreases in reach ranges are needed in the U.S. Access Board’s guidelines to accommodate the use of such devices, which are generally larger, heavier and less finely maneuverable than manual wheelchairs. Since the 1970’s, research on the anthropometry of WhMD users has been conducted in Australia, the United Kingdom and Canada. All those countries have revised or are revising their standards based on that research.

In 30 years, many changes have occurred in nature of the U.S. population, the characteristics of people who use WhMDs and the characteristics of equipment that they use. Many more power chairs are in use now than in the 1970’s. Significant advances in wheeled mobility technology, health care, public health and demography have occurred that had an impact on the anthropometry of wheeled mobility users. For example, power wheelchairs and scooters are often larger in size than manual wheelchairs. In addition, improved health care technology has allowed people with more serious disabilities to survive longer than in earlier decades. These individuals may have conditions that affect their abilities to maneuver devices in small spaces or reach objects. A significantly broader range of devices is now available, from highly-adjustable battery-powered wheelchairs to 3- and 4-wheeled scooters with front tillers. Scooters are growing in popularity but were not measured as part of the earlier research. Yet, the technical requirements in U.S. standards have not changed. It is likely that the current U.S. standards do not reflect the actual dimensions and abilities of contemporary WhMD users.

Very few studies of the anthropometry of WhMD users were conducted in the 1980s and 1990s, especially in the U.S. In response to this lack of current information, the IDeA Center, with funding from the National Institute on Disability and Rehabilitation Research developed new anthropometric measurement methods and a comprehensive anthropometric data set of over 200 WhMD users (Steinfeld, Feathers and Paquet, 2005; Feathers, Paquet and Drury, 2004; Paquet and Feathers, 2004). Rigorous scientific procedures were used in the development of the research methods and sophisticated software was created to organize and analyze the results. While much was accomplished in that study, there were important research needs that were unmet.  First, a larger sample was needed to provide a more accurate characterization of the anthropometry of WhMD users. Second, a more diverse sample in terms of ages and WhMD technologies was needed to help improve the representativeness of the sample. Third, new dissemination products were needed to help ensure that the research findings could be translated to design practice and standards development. Additionally, comparisons of international standards and research were needed to assess the adequacy of the current U.S. accessibility standards and help set priorities for improving regulations. Comparisons are also useful to identify best practices and differences related to cultural factors. Thus, in addition to collecting anthropometric data, the IDeA Center also completed a comparative analysis of research and standards on wheeled mobility in the U.S., the U.K., Australia and Canada. The analysis was limited to WhMD dimensions, minimum clear floor areas, space requirements for maneuvering, knee and toe clearances, and reach limits.


The objectives of the research were to:

1. Collect data on a sample of 500 individuals

2. Collect and compare research anthropometric research studies on wheeled mobility in Canada, the U.K. and Australia, with the U.S. standards and the research results from the current study.

3. Develop dissemination products including a final research report, tools for using the database and an online educational module.

All the anthropometry data was compiled in a database. Custom software was developed to manage the database that allows designers and standards developers to access the data using a graphical interface. Additional software was developed to facilitate expansion of the database and multi-site studies. Although the database provides a significant resource for researchers and standards developers, designers, particularly architects, interior designers and landscape architects need a different type of information. Thus the researchers also developed information tools in the form of this online educational course and graphic representations of the results that are more consistent with reference materials these professionals utilize in practice (See Design Resources).

The research findings highlight the importance of integrating research with standards development, organizing research collaborations and the need to develop standardized research methods. Now that a foundation and tools and procedures has been developed and extensively tested for systematic scientific research in this field, the cost of implementing future research using these methods has been significantly reduced. There is still much knowledge to be gained from further analysis of the data collected. The database is available for other researchers to utilize. The data is also available for use by human modeling software developers to augment their databases of people with no disabilities. But, there is still much that could be done beyond the scope of this work. The research team anticipates the development of future research collaborations and dissemination activities.

Learning Objectives

The objectives of this online educational module are to:

1. Provide a description of the research that compares anthropometric research studies on wheeled mobility in Canada, the U.K. and Australia, with the U.S. Standards.

2. Present a limited set of research findings from the current study funded by the National Institute on Disability and Rehabilitation Research (NIDRR) and the U.S. Access Board on clear floor area, forward and lateral reach and turning space.

3. Outline additional research needs.

4. Identify key dissemination resources including links to the final research report, tools for designers and other publications based on the research study.