Independent Wheelchair Transfers in the Built Environment: How Transfer Setup Impacts Performance Phase 2: Final Report

Transfer Heights

Despite differences in the data collection tools, some results from the second phase of the study were consistent with first phase of the independent transfer study.  For instance, level seat heights were 21.7± 1.2 inches and 22.1±1.4 inches for the first and second phases respectively. Both of these heights are outside of the standards for heights for most elements where adults would be expected to transfer (between 17 and 19 inches [7]).  Also, like the first phase, the second phase found that the majority of WMDs (92% of subjects in the first phase and the 5th percentile (or approximately 94% in this study) could transfer within one inch of the mean wheelchair seat to floor height (22 inches).   Transfers to level surfaces require less exertion on the upper extremities [5, 10, 11]. Transfers are easiest and safest to obtain when they are as close to level as possible [6]. This is consistent with other research results that have found that level transfers require less exertion on the upper limbs [5]. Based on the results of this study, it is estimated that the current standards would accommodate close to the 25th percentile of WMD users (approximately 75%) who can independently transfer to a transfer surface or platform.

The current station tested the ability of the study participants to transfer to an adjustable table height ranging from 10 inches to 43 inches. Although the study did not aim to determine what range of adjustable platform height would be needed to accommodate the majority of WMD users, the data from the subjects in this study (Table 9) suggests a range between 19 to 27.5 inches above the ground or floor surface. This is based on the lowest wheelchair seat to floor height and highest wheelchair seat to seat or floor height of the individuals in the study. All participants can make a level transfer, and the majority of participants can transfer 1 inch above or below their level seat height. Thus adjustability, including this range, would include all of the study participants and allow for greater accessibility where transfers are needed.