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

Transfer Protocols

In total 73 participants were enrolled the study. One participant was withdrawn because he self-reported being able to independently transfer meeting inclusion criteria but when he came in to do the study he was unable to transfer to any surface independently including a standard therapy mat table which was in the testing room. He was a bilateral amputee that used a power wheelchair. He was 57 years old with a height and weight of 73 inches and 285 lbs respectively. 

The remaining 72 participants completed all or part of the study protocols as shown in Figure 6. The primary reason why some participants did not complete all study protocols was due to an onset of pain or fatigue experienced part way through the study. 

Figure 6. Flow chart of the number of participants that did not complete each protocol (Protocols A, B and C) and participants that did not attempt the two step protocols (Protocols D and E)

Protocol A
Level Transfer:  All 72 study participants completed the level transfer in this protocol.
Maximum and Minimum Height Transfers:  One the 72 study participants (P1) developed hip pain and did not attempt these two transfers. He was a 52 year old amputee with a weight and height of 220 lbs and 62 inches respectively, who used a manual wheelchair. His data were not included in the result tables. Two participants (P2 and P3) did not attempt to transfer higher or lower than their mobility seat for different reasons.  Participant P2 was a 64 year old female with Multiple Sclerosis and used a power chair. Her weight and height were 210 lbs and 66 inches respectively and she lacked the ability to transfer to surfaces that were not at the same level as her wheelchair seat to floor height. Participant P3, was unable to transfer higher or lower than her mobility device seat without the presence of grab bars on the platform. She was a 46 year old female with Multiple Sclerosis that also used a power chair. Her height and weight were 69 inches and 154 lbs respectively. These two participants were included in the results tables with their level seat height being recorded as their maximum and lowest height transfer for this protocol.

Protocol B
Level Transfer: All 72 study participants completed the level transfer in this protocol.
Maximum Height Transfer:  Of the 72 participants, participant (P2) did not attempt to transfer higher than her mobility device seat because she lacked the ability.  Like protocol A her level height was recorded as her maximum height for this protocol.
Minimum Height Transfer: Of the 72 participants, P4, developed fatigue and was unable to attempt this transfer. He was a 70 year old male with a spinal cord injury who uses a manual wheelchair. His weight and height were 157 lbs and 68 inches respectively. Participant (P2) did not attempt to transfer lower because she lacked the ability. Her data were included in the results and level seat height was recorded as her minimum transfer height.

Protocol C
Level Transfer:  All 72 participants completed the level transfer in this protocol.
Maximum Height Transfer:  Of the 72 participants, one participant (P2) again did not attempt this transfer because she was unable to transfer higher than her mobility device seat. Like the other protocols her level transfer height was used as the maximum transfer height in the results.  
Minimum Height Transfer:  Of the 72 participants, one participant (P4) had developed fatigue and was unable to attempt this transfer. His data was not included in the analysis.  Participant (P2) did not attempt the transfer because she was unable to transfer lower than her mobility device seat. Like the other protocols her level height was used as the minimum height in the analysis. Participant P3, attempted the transfer but was not successful at completing it (e.g. failed attempt). Her data were included in the data analysis and her level transfer height was used as the minimum height in the analysis.

Protocols D and E
For protocols D and E there were several participants who were unable to complete the two step transfer. The demographics of these individuals are listed in Table 8. For these protocols, participants either attempted the protocol and failed or did not attempt the protocol after visual inspection. For these protocols a failed transfer, is one where the participant transfers to the first platform, but was unable to transfer to the second platform. For protocol D 11% (8/72) of the participants did not attempt it and of the 64 participants who did attempt the protocol, 5% (3/64) had a failed attempt. For protocol E transferring to a higher platform with the ramp, 11% (8/72) of the participants did not attempt the protocol and of the 64 participants who attempted the transfer 11% (7/64) had a failed attempt. When transferring to a lower platform with the ramp, 13% (9/72) did not attempt the transfer and of the 63 subjects who attempted the transfer, 3.2% (2/63) had a failed attempt.  Participants who did not attempt two-step transfers or had failed transfers were not included in the results tables for these types of transfers.

Table  8. Characteristics of participants who did not attempt a transfer or had a failed transfer during the two-step transfer protocols D and E. 

Note. D1 = Protocol D transfer level to increment higher, D2 = Protocol D transfer level to increment lower, E1 = Protocol E transfer level to increment higher, E2 = Protocol E transfer level to increment lower. aDiagnosis acronyms = SCI (Spinal cord injury), COPD (and Chronic obstructive pulmonary disease), CP (Cerebral palsy), MS (Multiple Sclerosis ), MD (Muscular Dystrophy). bWC Type = Wheelchair Type used, P (power wheelchair), M (manual wheelchair).