The Impact of Transfer Setup on the Performance of Independent Transfers: Phase I Final Report

Executive summary

For individuals who rely on wheeled-mobility devices (WMD), performing transfers is essential to independence with activities of daily living at home and participation in the community.  Transfers are required for getting to and from the device to bed, bathtub, car seat, among others.  The United States Access Board develops guidelines and maintains design criteria for the built environment to maximize accessibility for persons with disabilities.  The objective of this study was to analyze the impact of transfer setup on performance of independent transfers. The first aim of the study was to perform an expert review of the current knowledge regarding transfers and the impact of setup. Results showed a consensus among studies that transferring to a higher surface implies greater exertion of the upper limb.  Yet, there is no evidence concerning height differences, horizontal distance, and space needed next to the target surface so it can be accessible by a majority of WMD users.  The second aim was to compare the current guidelines for amusement park rides with the results obtained by evaluating the impact of setup on transfer performance using a custom-built transfer station.  We evaluated WMD users who lived in the community, who were able to transfer independently and who represented a broad spectrum of disabilities.  We evaluated the impact of height differential, gap, placement of a non-removable armrest, and the effect of grab bars. Results showed that height differentials above and below WMD seat height, gaps and obstacles pose serious transfer-related accessibility problems for WMD users therefore suggesting the need of updated guidance for these standards.

Key findings:

• There are a small number of studies that directly relate to the influence of transfer setup on performing independent transfers and thus points to a critical need for more studies in this area.

• The minimum length and width included in the clear floor space requirements located adjacent to the ride seat or transfer device do not accommodate many wheeled mobility device users.

• The majority of users (92%) could transfer to a surface at a height similar to the median WMD seat to floor height of the sample (22 in).  About 43% could transfer to a surface 14” high and 85% could transfer to a surface 24” high with respect to floor when no gaps or obstacles were present. 

• Gaps of at least 3.5 in at a height level with the WMD are achievable by 95% of our sample, however results showed that managing higher or lower transfers heights with gaps is much more difficult as compared to without the gap.

  •  58% of the WMD users could transfer to a level surface if there was an obstacle (e.g. 6” high non-removable armrest) next to the surface. 

  • Our data suggest that while obstacles are challenging adding a grab bar in front of the transfer seat helped negotiate height differences better and even enabled some users who could not transfer with the obstacle (e.g. armrest) the ability to perform the transfer with the obstacle. 

  • Our subjects preferred the front grab bar height to be between 30” (76.2 cm) and 33” (83.8 cm).