THE IMPACT OF TRANSFER SETUP ON HAND POSITIONING DURING INDEPENDENT TRANSFERS

Genevieve M. Jerome, BE; Maria L. Toro, MS; Alicia M. Koontz, Phd, RET; Rory A. Cooper, PhD Human Engineering Research Laboratories, Department of Veterans Affairs, Pittsburgh, PA; Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA;

BACKGROUND old, (2) able to independently perform a transfer For individuals who rely on wheeled mobility to/from a wheeled mobility device (WMD) with or devices (WMD), performing transfers is essential to without a transfer board, (3) owned a WMD, and (4) independence with activities of daily living in the home had been using the WMD for at least one year. and participation in the community (Toro, Koontz, Eligibility to participate in the study was denied to Kankipati, Naber & Cooper 2010). Transfers are subjects who had significant upper extremity pain or required for getting to and from the device to bed, bath injury that would inhibit the ability to perform transfers tub, and motor vehicle seat, among others. Performing and had an active or recent history of pressure sores. these transfers are directly associated to upper limb Subject testing took place at the 24th National Disabled injury and pain for individuals. Transfer related injuries Veterans Winter Sport Clinic in Snowmass Village, can lead to a decrease in independence and Colorado during March 2010; at the 30th National community involvement as well as depression and an Veterans Wheelchair Games in Denver, Colorado increase in health risks (Koontz, Kankipati, Yen-Sheng during July 2010; at the Hiram G Andrews Center in & Cooper, 2011; McClure, Boninger, Ozawa & Koontz, Johnstown, Pennsylvania during November 2010 and 2011). The United States Access Board develops March 2011; during the US Access Board In-Person guidelines and maintains design criteria for the built Meeting in Chicago, Illinois during September 2010; at environment to maximize accessibility to public places the Human Engineering Research Laboratories in (ADA standards, 1994; ADA accessibility 2002). Pittsburgh, Pennsylvania between June 2010 and April Current standards have criteria only related to seat 2011; and at H. John Heinz III VA Progressive care height and clear floor space (Board, U.S.A., 2003). center in June 2011. Several studies have suggested that the addition of Description of Transfer Station grab bars in patient rooms as well as in the homes of The testing was performed on a custom-built the elderly can reduce the risk of falls and injury and modular transfer station that was designed using Solid will promote for a safer environment (Jones & Tamari, Edge 2009. It consisted of a height adjustable platform 1997; Sveistrup, Lockett, Edwards & Aminzadeh, with a range between 10” to 29” (25.4-73.7 cm) with 2006). Data on transfers from a broad spectrum of increments every inch (2.5 cm). The station was also community-dwelling mobility device users is needed equipped with a fixed backrest 17” wide by 25” high on the use and placement of handhelds or grab bars (63.5x43.2 cm) and had a 95° recline; a lateral grab for facilitating transfers, the ranges of heights that bar with a fixed height of 32” (81.3 cm) that allowed for individuals can realistically transfer up and down to, attaching/detaching side guards (e.g. obstacle to how close the transfer surfaces need to be, and how transfer) and grab bars of varying heights (Figure 1) obstacles in between the device and target surface from 19”-38” (48.3-96.5 cm) with increments every 2” effect transfer performance. Not only will data on hand (5.1 cm). The grab bars diameter was 1” (2.5 cm). The positioning during independent transfers help designer space for the legs and feet had a fixed dimension of and engineers to develop better accessible 14.5” deep by 22.5” wide (36.8x57.2cm). environments, but it will also aid occupational therapist and clinicians in promoting independence and empowerment to their clients. METHODOLOGY Subjects Eligibility to participate in the study was based on the following criteria: (1) they were at least 18 years Figure 1- Transfer station initial setup (left) and with front grab bar and side guard (right). Experimental Protocol recorded. Then from initial setup, the horizontal Level Height Protocol: The initial setup involved no distance between the wheelchair and platform was side guard or font grab bar. The platform was adjusted incrementally increased and the maximum attainable so that it was level with the subject’s WMD. Subjects gap distance was recorded. The side guard height was positioned themselves as they normally would to adjusted to always remain at 6” from the WMD seat prepare for a transfer. The angular orientation and when lowering the station and was not adjusted when linear distances of the WMD with respect to the front the station’s height was above the height of the WMD most corner of the platform were recorded. Each seat. subject was asked to perform a transfer from their Front Grab Bar Protocol: From the initial setup, a grab WMD to the station and then back to their WMD. The bar in front of the platform was added and four use of grab bar(s) was noted for each transfer. Next, conditions in random order were tested: low grab bar they were asked to perform 6 protocols in random no side guard; high grab bar no side guard, low grab order. They were also asked to exercise sound bar and side guard, high grab bar and side guard. judgment in performing the transfers and to only do Subjects had the option to use the front grab bar or not transfers they felt comfortable and safe doing. and selected the grab bar height in each condition Subjects were spotted in the event they would begin to tested. They performed a level height transfer in each slip/fall during a transfer. If this was the case the condition and afterwards performed the variable height transfer was declared ‘unattainable’. After each portion of the protocol as described previously (e.g. transfer in each protocol, changes made to device Adjustable Height Protocol). Maximum and minimum positioning and leading/trailing hand placement were heights attainable, front grab bar use, and grab bar recorded. heights were recorded. Adjustable Height Protocol: From the initial setup, only Data Analysis the height of the platform was adjusted incrementally: The number of subjects that attempted to higher and lower than the subject’s seat. The amount perform each protocol and the number of subjects that of vertical distance that the seat was raised/lowered were not able to attain the transfer(s) with that each time depended on the subject’s perceived and configuration were reported for each protocol. From observed transfer abilities. The maximum and these subjects the number of subjects that performed minimum heights the subject could transfer to/from the each parameter of protocols C, D, E, and F as well as platform were recorded. had performed either both parameters of protocol A, Adjustable Gap Protocol: From the initial setup, just performed protocol B, or both A and B were reported. the horizontal distance between the WMD and Hand position placement for leading to the transfer platform was incrementally increased by placing station, trailing to the transfer station, leading from the plywood blocks of 3.5” (8.9 cm) width between the transfer station, and trailing from the transfer station transfer station and the WMD. The platform height were the focus for these subjects. The hand placement remained level with their WMD seat height. The options recorded were on the backrest, platform, amount of horizontal distance increased each time wheelchair, lateral grab bar, front grab bar, and side depending on the subjects perceived and observed guard. The option of “other” was recorded for subjects transfer abilities. The maximum horizontal distance the that placed their hands on something else or did not subject could transfer to/from the platform was need to place their hand anywhere for that transfer. A recorded. count of how many times the 19 subjects positioned Adjustable Height/Gap Protocol: From the initial setup, their hands on each placement option was calculated a gap separating the device and platform was for the leading and trailing hands when transferring to introduced with the plywood blocks of 3.5” (8.9 cm) and from the station in each parameter for all and then the height of platform was adjusted protocols. Also, a count of how many subjects incrementally higher/lower. This procedure was switched their hand placement during similar protocols repeated until the largest horizontal distance was was also calculated for the 49 combination options. reached. The maximum and minimum heights Descriptive statistics (e.g. means, medians, attainable with the largest horizontal distance were frequencies, standard deviations) of the data were recorded. calculated for the subjects that were able to attain the Side Guard Protocol: From the initial setup, two side transfers in each protocol. Population proportion guards adjusted 6” (15.2 cm) higher than the subject’s confidence intervals (CI) were determined at 95%. WMD seat were attached, and subjects were asked to perform a level height transfer. Then the height of the RESULTS platform was adjusted incrementally in height: higher Subjects and lower than the subject’s seat and the maximum The narrowed down sample consisted of 16 transfer heights high/low that were attainable were men and 3 women with an average age of 46.7 ± 16.7 years, body weight of 192.89 ± 61.99 lbs (87.50 ± trailing hand from the station were on the platform (9) 28.12 kg) , and height of 66.47 ± 5.43 in (30.15 ± 2.46 and the lateral grab bar (5). m). Seven had spinal cord injury (SCI), three had Adjustable Height/Gap Protocol cerebral palsy (CP), three had spina bifida, two had This protocol consisted of two parameters: multiple sclerosis (MS), one had spinal stenosis, one maximum gap lowest height and maximum gap had epiderminal cyst, one had muscular dystrophy highest height. Nineteen subjects completed the (MD), and one had both MS and SCI. The levels of protocol. SCI ranged from L2 to C6 with 85.7% of the sample Maximum Gap/Lowest Height: The most used hand having incomplete injuries and one not recorded. The placements for the leading hand to the station were on sample as a whole had been using a WMD for 10.95 ± the platform (9) and the lateral grab bar (9). The 7.99 years with a range from 2 to 26 years. The wheelchair was used by 14 subjects for the trailing average wheelchair seat plus the cushion height hand to the station. The wheelchair was used by 17 measured at the edge was 21.53 ± 1.3” (54.7 ± 3.3 subjects for the leading hand from the station. The cm). The median was 21.5” (54.6 cm) and the range most used hand placements for the trailing hand from was 19 – 24” (48.2 – 60.9 cm). Twelve subjects used the station were on the platform (10) and the lateral manual wheelchairs (MWC), six used power grab bar (6). wheelchairs (PWC), and one used a scooter. Maximum Gap/Highest Height: The most used hand Level Height Protocol placements the leading hand to the station were on the Nineteen subjects completed this protocol. platform (11) and the lateral grab bar (7). The When transferring to the station the platform was used wheelchair was used by 13 subjects and the platform the most for the leading hand by a total of 16 subjects. was used by 6 for the trailing hand to the station. The The wheelchair was used by 18 subjects for the trailing wheelchair was used by 17 subjects for the leading hand. When transferring from the station the hand from the station. The most used hand wheelchair was used by 17 subjects for the leading placements for the trailing hand from the station were hand. The most used hand placements for the trailing on the platform (13) and the lateral grab bar (4). hand from the station were on the platform (11) and Side Guard Protocol the lateral grab bar (7). This protocol consisted of three parameters: Adjustable Height Protocol side guard maximum height, side guard minimum This protocol consisted of two parameters: height, and side guard level maximum gap. Nineteen maximum height and minimum height. Sixteen subjects completed the protocol. subjects completed the protocol. Side Guard Max Height: The most used hand Maximum Height: The most used hand placements for placement for the leading hand to the station was on the leading hand to the station were on the platform (7) the side guard (9). The wheelchair was used by 11 and the lateral grab bar (7). The wheelchair was used subjects and the side guard by 5 for the trailing hand by 12 subjects for the trailing hand to the station. The to the station. The wheelchair was used by 11 subjects wheelchair was used by 14 subjects for the leading and the side guard by 7 for the leading hand from the hand from the station. The most used hand station. The most used hand placements for the placements for the trailing hand from the station were trailing hand from the station were on the side guard on the platform (9) and the lateral grab bar (5). (10) and the platform (6). Minimum Height: The most used hand placements the Side Guard Min Height: The most used hand leading hand to the station were on the platform (8) placements for the leading hand to the station were on and the lateral grab bar (7). The wheelchair was used the lateral grab bar (10) and the side guard (8). The by 14 subjects for the trailing hand to the station. The wheelchair was used by 10 subjects and the side wheelchair was used by 16 subjects for the leading guard by 8 for the trailing hand to the station. The hand from the station. The most used hand wheelchair was used by 14 subjects and the side placements for the trailing hand from the station were guard by 4 for the leading hand from the station. The on the platform (8) and the lateral grab bar (5). most used hand placements for the trailing hand from Adjustable Gap Protocol the station were on the side guard (9) and the lateral Seventeen subjects completed the protocol. grab bar (5). The most used hand placements for the leading hand Side Guard Level Max Gap: The most used hand to the station were on the platform (10) and the lateral placements for the leading hand to the station were on grab bar (6). The wheelchair was used by 14 subjects the side guard (11) and lateral grab bar (5). The for the trailing hand to the station. The wheelchair was wheelchair was used by 11 subjects and the side used by 15 subjects for the leading hand from the guard by 6 for the trailing hand to the station. The station. The most used hand placements for the wheelchair was used by 15 subjects for the leading hand from the station. The most used hand placement for the trailing hand from the station was on the side that happened most frequently was from the lateral guard (12). grab bar to the side guard which occurred 4 times. Front Grab Bar Protocol Adjustable Height Protocol (Max) to Front Grab Bar This protocol consisted of four parameters: Protocol (Max): When transferring to the station the side guard maximum height, side guard minimum leading hand placements that subjects switched most height, and side guard level maximum gap. Nineteen frequently were from the lateral grab bar to the front subjects completed the protocol. grab bar and from the platform to the front grab bar Front Bar Lowest Height: The most used hand which occurred 6 and 4 times respectively. The most placements for the leading hand to the station were on frequent trailing hand switch was from the wheelchair the front grab bar (10) and the platform (4). The to the side guard which occurred 5 times, while 6 wheelchair was used by 9 subjects and the front grab subjects did not switch. When transferring from the bar by 7 subjects for the trailing hand to the station. station the most frequent leading hand switch was The wheelchair was used by 14 subjects for the from the wheelchair to the side guard which occurred 5 leading hand from the station. The most used hand times, while 8 subjects did not switch. The trailing placement for the trailing hand from the station was on hand placement that happened most frequently was the front grab bar (13). from the lateral grab bar to the side guard which Front Bar Max Height: The most used hand occurred 4 times. placements for the leading hand to the station were on Adjustable Height Protocol (Max) to Level Height the front bar (13) and the platform (4). The platform Protocol: When transferring to the station the leading was used by 11 subjects and the wheelchair and front hand placements that subjects switched most grab bar were both used by 4 subjects for the trailing frequently were from the lateral grab bar to the hand to the station. The wheelchair was used by 15 platform which occurred 5 times. Seven people did not subjects for the leading hand from the station. The switch their hand placement from the platform. The most used hand placements for the trailing hand from most frequent trailing hand switch was from the the station were on the front grab bar (12) and the platform to the wheelchair which occurred 4 times, platform (7). while 12 subjects did not switch from the wheelchair. Front Bar + Side Guard Lowest Height: The most used When transferring from the station the 13 subjects did hand placement for the leading hand to the station was not switch hand placement form the wheelchair. Six on the front bar (14). The wheelchair and the side subjects did not switch their hand placement from the guard were both used by 7 subjects while the front platform for the trailing hand. grab bar was used by 4 subjects for the trailing hand to Adjustable Height Protocol (Min) to Side Guard the station. The wheelchair was used by 14 subjects Protocol (Min): When transferring to the station the for the leading hand from the station. The most used leading hand placements that subjects switched most hand placements for the trailing hand from the station frequently were from the platform to the lateral grab were on the front grab bar (14). bar which occurred 4 times. Five people did not switch Front Bar + Side Guard Highest Height: The most their hand placement from the lateral grab bar. The used hand placement for the leading hand to the most frequent trailing hand switch was from the station was on the front bar (16). The side guard was wheelchair to the side guard which occurred 4 times, used by 13 subjects for the trailing hand to the station. while 9 subjects did not switch from the wheelchair. The wheelchair was used by 9 subjects and the side When transferring from the station 4 subjects switch guard by 5 for the leading hand from the station. The from the wheelchair to the side guard, while 11 most used hand placement for the trailing hand from subjects did not switch hand placement from the the station was on the front grab bar (11). wheelchair. The trailing hand placement that Hand Positioning Switches happened most frequently was from the platform to the Adjustable Height Protocol (Max) to Side Guard side guard which occurred 4 times. Protocol (Max): When transferring to the station the Adjustable Height Protocol (Min) to Front Grab Bar leading hand placements that subjects switched most Protocol (Min): When transferring to the station the frequently were from the platform to the side guard leading hand placements that subjects switched most and from the lateral grab bar to the side guard which frequently were from the platform to the front grab bar occurred 4 times each. The most frequent trailing hand and from the lateral grab bar to the front grab bar switch was from the wheelchair to the side guard which occurred 5 and 4 times respectively. The most which occurred 5 times, while 6 subjects did not frequent trailing hand switch was from the wheelchair switch. When transferring from the station the most to the front grab bar which occurred 4 times, while 7 frequent leading hand switch was from the wheelchair subjects did not switch from the wheelchair. When to the side guard which occurred 5 times, while 8 transferring from the station 4 subjects switched from subjects did not switch. The trailing hand placement the wheelchair to the side guard, while 11 subjects did not switch hand placement from the wheelchair. The direction of where they are going with the leading hand trailing hand placements that happened most as the trailing hand is placed on where they are frequently were from the lateral grab bar to the front coming from. For protocols that involved an obstacle grab bar and the platform to the front grab bar which as in a side guard or front bar using that obstacle to occurred 5 and 4 times respectively. place their hands was amongst the majority of what Adjustable Height Protocol (Min) to Level Height subjects tended to do. Similar hand positions were Protocol: When transferring to the station the leading used for similar parameters and protocols. hand placements that subjects switched most For the hand switch analysis, along with the frequently were from the lateral grab bar to the results mentioned above there were also many platform which occurred 5 times, while 8 subjects did placement combinations that that occurred 1, 2, or 3 not switch from the platform. Eleven subjects did not times. The wheelchair was used amongst the majority switch from the wheelchair for the trailing hand. When of subjects for the trailing to the station and leading transferring from the station, 14 subjects did not switch from the station hand switch comparisons for the all leading hand placement from the wheelchair. 6 and 4 protocols. subjects did not switch trailing hand placements from Subjects are representative of a highly functioning the platform and the lateral grab bar respectively. sample and therefore these results may not be Adjustable Gap Protocol to Level Height Protocol: representative of the general population of WMD When transferring to the station 10 subjects did not users. Overhead grips were not available and could switch leading hand placement from the platform. 13 have affected subject choice in hand placement. The subjects did not switch trailing hand switch placement results of this study could help airlines, motor vehicle from the wheelchair. When transferring from the and adaptive equipment manufacturers to improve station 13 subjects did not switch leading hand their design. placement from the wheelchair. 8 and 4 subjects did ACKNOWLEDGEMENTS not switch trailing hand placements from the platform The material used for this study was funded by the and the lateral grab bar respectively. Side Guard Department of Education (NIDRR), United States Protocol (Max) to Front Grab Bar Protocol (Side Guard Access Board grant H133E070024 and Project Max): When transferring to the station the leading #84.133E. hand placements that subjects switched most Thank you to the Human Engineering Research frequently were from the side guard to the front grab Laboratories where the work for this study was bar and from the lateral grab bar to the front grab bar performed. which occurred 10 and 4 times respectively. The most The contents do not represent the views of the frequent trailing hand switch was from the wheelchair Department of Veterans Affairs or the United States to the side guard which occurred 7 times, while five Government. people did not switch their hand placement from the REFERENCES side guard. When transferring from the station 7 1.Toro, M.L., Koontz, A. M., Kankipati, P., Naber, M., subjects did not switch from the wheelchair. The Cooper, R. A. Independent wheelchair transfer: a trailing hand placement that happened most frequently systematic literature review. in Proceedings of the was from the side guard to the front grab bar and from Rehabilitation Engineering and Assistive Technology the lateral grab bar to the front grab bar which Society of North America Conference. 2010. Las occurred 6 and 4 times respectively. Vegas, NV. Side Guard Protocol (Min) to Front Grab Bar Protocol 2. Koontz, A. 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