Anthropometry of Wheeled Mobility Project: Final Report

Section 6.0 Conclusions

The key findings of the research are:

1. Sample composition: There are important differences in the sample based on recruitment methods. This emphasizes the importance of multi-site studies for this population.

2. Diversity: There are often large differences in the body and chair sizes and in the functional abilities of manual chair, power chair and scooter users, and men and women.

3. Measurement parameters: There are no generally accepted and shared definitions of variables for both anthropometric research and standards development, which impedes integration of research and practice.

4. International comparison: Different countries use different approaches to developing standards based on anthropometry. None of the standards reviewed had a comprehensive and explicit approach to evidence based practice.

5. Landmarks: Some dimensions in standards do not correspond to clear measurement landmarks on the body and device, creating barriers in translating research findings to standards development.

6. Reference WhMD: The U.S. standard reference wheelchair does not represent the sizes of unoccupied wheelchairs in our sample well. Contemporary wheeled mobility devices are much more diverse in size and features than the reference wheelchair.

7. Clear floor space: A large minority of participants in our research would not be accommodated by the current U.S. standard for clear floor space, especially for length. The people excluded include those who use any of the three types of WhMD. Other countries have already increased the clear floor space used in their standards.

8. Seat height: Seats for a majority of our sample have seat heights above that shown in the reference wheelchair in U.S. standards, especially the power chairs and scooters.

9. Knee and toe clearances: Current U.S. standards for knee and toe clearances do not accommodate a majority of participants in our sample.

10.Maneuvering clearances: A significant proportion of WhMD users, scooter users in particular, are not accommodated by current maneuvering clearances in U.S. standards, although the proportion differs for different clearances. In particular, the current standards do not accommodate most of our sample for completing a 360-degree turn. There are also a small number of participants in all categories who require much larger clearances than current standards provide.

11. Reaching ability: A significant percentage of WhMD users have very limited functional reaching abilities.

12. Reach limits: A majority of WhMD users cannot complete a forward reach to the minimum forward reach height in U.S. standards on a vertical plane in front of their anterior most point (toes or device). The current high side reach limit accommodates WhMD users. The low reach limit, as defined, is currently inappropriate for safety reasons.

13.Operating forces: The maximum operating force in the current standards is too high for the majority of WhMD users.

14. Door usability: The usability study confirmed many of the existing clearance requirements for doors but also identified the need for improving some others, especially the door clearance width. Findings support the increased use of automated doors and the development of improved closer technologies.

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 of 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 is significantly reduced.

There is still much knowledge to be gained from further analysis of the data collected. The database is available for other invited researchers to utilize. The data is also available for use by human modeling software developers to augment their databases of people with no disabilities. The research team anticipates the development of future research collaborations, dissemination activities and standards development activities.

Much was learned about anthropometry of wheeled mobility during the course of this project. Yet, much more needs to be discovered. In particular, there is a need to continue gathering data to keep pace with developments in practice. A good model is the periodic survey conducted in the U.K. (Stait et al., 2000; Hitchcock et al., 2006). While the research methods used in the U.K. program (2-D photogrammetry) only provide data on limited landmarks like occupied width and length and the features of devices, it can be used to identify trends in equipment used by consumers and the need for targeted studies on specific types of devices.

Having established an extensive database, the need to measure a large number of people with three-dimensional methods is now reduced. The current data archives will provide sufficient data to answer many research questions. But, the findings show that different data collection sites have access to different user groups. Thus another important research activity in this field should be the development of a long range data collection effort on a national scale with a diverse set of research settings. Small numbers of people can be measured by cooperating with clinical settings and equipment moved from place to place. Developing a network of data collection settings in academic rehabilitation science departments or major clinical settings could also help to improve education on accessibility for the rehabilitation professions, an important stakeholder group, and build capacity for research.

Research that would produce longitudinal data on WhMD use would be very useful, especially to improve WhMD design and reimbursement policies. The current sample could serve as a recruitment pool for such a project. When recruiting individuals, we asked for permission to retain their contact information for future research and most participants agreed. Some are already participating in other research at the IDeA Center. Our demographic survey results and other anecdotal information obtained by WhMD users suggests that wheeled mobility device users often have more than one device, use different devices for different purposes and have unmet needs for equipment that are not being addressed by current third party reimbursement policies. An individual’s needs also change over time with age and stage of life as they pursue different social roles and their body changes. In particular, the impact of progressive diseases like MS, ALS, Parkinson’s Disease and Post Polio Syndrome, on equipment needs requires more information. A longitudinal study could identify the long-range experience of consumers of devices. It could also explore the needs for consumer education and changes in purchasing policy to improve appropriate selection of devices for the environments in which they are used.

In-depth studies with small samples are needed to understand the interaction of wheeled mobility users with the built environment. The resources available in this study were devoted to measuring a large sample of individuals. In-depth studies are needed on the performance of WhMD users in specific environments such as workstations, paratransit vehicles and taxis, rest rooms on vehicles, doorways and ramps. More extensive research on doors than what was conducted in this project would be valuable as well. Such studies should examine the effect of learning on task performance. Currently, the IDeA Center has in-depth studies underway on short ramps, public transit buses and outdoor walking surfaces. We are applying new research methods to collect data on participants in motion in order to develop dynamic human models. Many of our research participants come from our sample pool and we will complete structural measurements for new participants as they are recruited and add those measurements to the database archive. The new research will allow us to study the relationships between demographic variables, structural and functional anthropometric variables, and task performance in motion, similar to what we did with the door maneuvering study but including quantitative body motion analysis performance variables.

In dissemination, the research team will continue to publish refereed journal articles based on our research. Updates will be made to existing articles on reach, clear floor area, turning space and structural measurements. New articles will be completed on door maneuvering, and knee and toe clearance. We will also prepare a proposal to a scientific book publisher to produce an authoritative book on the anthropometry of wheeled mobility that brings all the articles that we and our colleagues at other research centers have written together. This publication will also include all the accommodation models.

The long-range goal of applying the database through human modeling needs continued attention. We hope this will occur first through efforts to develop a standard practice on accessible design of transportation vehicles. This will include the further development and testing of the accommodation models and the development of a series of 3-D virtual manikins that can be used to test vehicle designs in virtual 3-D space. Outreach will also be conducted to find a human modeling software producer to adopt the database as part of a commercial product.

In standards development, the first priority will be to work with the Task Force on Anthropometry of the ICC/ANSI A117 Committee, the Province of Ontario Committee and the GUDC Consensus Standards for Commercial Buildings Committee, all of which have expressed strong interest in our findings and recommendations. Working with three standards groups simultaneously, we hope to evolve a new approach to the “building blocks” of wheeled mobility anthropometry that can take into account larger devices in a cost effective manner.

Another important stakeholder group in the standards field is RESNA’s WC−19 Committee on wheelchair standards. The major U.S. wheelchair manufacturers are also involved in this effort. This seems to be the most likely venue to engage the industry in developing initiatives to develop wheelchairs that provide more accessibility in the built environment and consumer and professional education materials to inform customers and rehabilitation practitioners on the features they should seek when purchasing equipment. Engaging experts from the manufacturing sector and R&D organizations to assess the future of WhMD design is very important both in learning what changes may be on the horizon that could affect anthropometry of WhMD and also to help improve the usability of new products within the built environment. RESNA is another good venue for this type of effort.

There is also a need for further education among those in the design professions, consumers and those in the rehabilitation science professions. By providing the existing online course to all three audiences, we can assess additional educational needs and evaluate its features and content. This feedback will be used to make improvements in the current course. It will also help to define the priorities for further modules which could include additional design issues, research methodology, use of the interactive database, and design applications. This educational work can include findings from current targeted research studies underway at the IDeA Center. The present course is designed to fit the scope of a self-instructional module but future development could also include a longer-range program with instructors for a more extensive and in-depth continuing education experience.