TransKinect: a computer vision and machine learning clinical decision support system for automatic independent wheelchair transfer technique assessment.

BACKGROUND: Physical and occupational therapists provide routine care for manual wheelchair users and are responsible for training and assessing the quality of transfers. These transfers can produce large loads on the upper extremity joints if improper sitting-pivot-technique is used. Methods to assess quality of transfers include the Transfer Assessment Instrument, a clinically validated tool derived from quantitative biomechanical features; however, adoption of this tool is low due to the complex usage requirements and speed of typical transfers. OBJECTIVE: The objective of this study is to develop and validate a computer vison and machine learning solution to better implement the Transfer Assessment Instrument in clinical settings. METHODS: The prototype system, TransKinect, consists of an infrared depth sensor and a custom software application; usability testing was carried out with fifteen therapists who performed two transfer assessments with the TransKinect. Proficiency in using features, usability, acceptability and satisfaction were analysed with validated surveys and themes were extracted from the qualitative feedback. RESULTS: The therapists were able to successfully complete the transfer quality assessments with 86.7 ± 5.4% proficiency. Total scores for System Usability Scale (77.6 ± 14.7%) and Questionnaire for User Interface Satisfaction (83.5 ± 8.7%) indicated that the system was usable and satisfactory. Qualitative feedback indicated that TransKinect was user-friendly, easy to learn, and had high potential. DISCUSSION: The results support TransKinect as a potential clinical decision support system for therapists for the comprehensive assessment of independent transfer technique. Future research is needed to investigate the utility and acceptance of TransKinect in real clinical environments. Implications for RehabilitationMachine learning and computer vision can be used to analyze transfer techniqueTransKinect is a usable and user-friendly means for therapists to automate analysisSummary reports and videos of transfers show high potential for clinical useAdoption of TransKinect can increase quality of care for manual wheelchair users.

Development and content validity of the caregiver assisted transfer technique instrument.

Informal caregivers often provide transfer assistance to individuals with disabilities; however, repeated transfers are associated with a high risk of musculoskeletal pain and injury, and training and education around transfers is minimal. The purpose of this study was to develop and assess the content validity of a new tool, the Caregiver Assisted Transfer Technique Instrument (CATT), which could be used to provide an objective indicator of transfer performance. Item importance, clarity, and appropriateness of responses were rated on a five-point Likert scale by clinicians (n = 15), informal caregivers (n = 10), and individuals with spinal cord injury (n = 5). The content validity index and modified Kappa of each item was calculated. Participants also provided qualitative feedback on item content. In general, items were rated favorably for their importance (4.47 to 5.00), clarity (4.33 to 4.90), and appropriateness of responses (4.38 to 4.90), and most items had excellent content validity (k* ≥ 0.75). Feedback from participants led to the creation of two versions of the CATT: one for manual lifting techniques (CATT-M) and one for transfers performed via lift-based technologies (CATT-L). Future work will focus on establishing the reliability and validity of the CATT as well as developing training and education interventions surrounding assisted transfers.

Discovering Provider Awareness of Mobility Assistive Technologies and Clinical Guidelines- A Comparative Analysis with Consumer Responses.

OBJECTIVE: This study aims to enhance the accessibility and quality of mobility assistive technology (MAT) by investigating and bridging knowledge gaps between MAT providers and consumers with ambulatory limitations. DESIGN: A survey was conducted among MAT providers in the United States, consisting of sections on awareness, knowledge importance and desire, and knowledge sources. The responses were compared to data collected from consumers in a previous study. RESULTS: A total of 144 MAT providers participated, with 60% having received academic or professional training in relevant fields. Analysis revealed significant knowledge gaps between providers and consumers, particularly in AT assessment tools and knowledge sources. Moderate gaps were also observed in areas such as clinical practice guidelines, desired MAT information, and knowledge sources. However, the gaps in other areas were relatively small. CONCLUSION: This study highlights the knowledge gaps between MAT providers and consumers, hindering the optimal utilization and fulfillment of user needs. Providers possess valuable information that consumers may lack, positioning them as primary knowledge sources. Addressing these gaps through targeted interventions, improved communication channels, and enhanced education can enhance the utilization of MAT and improve outcomes for individuals with ambulatory limitations.

Comparison of trunk mechanics and spatiotemporal outcomes in caregivers using a robotic assisted transfer device and a mobile floor lift.

OBJECTIVE: The purpose of this study was to compare trunk mechanics, distance covered, and average instantaneous velocity and acceleration recorded with caregivers performing transfer tasks using a research mannequin with both a prototype robotic assisted transfer device (RATD) and a mobile floor lift. DESIGN: Cross-Sectional. SETTING: Biomechanics Lab and Human Engineering Research Laboratories. PARTICIPANTS: Caregivers (N = 21). INTERVENTION: Robotic Assisted Transfer Device. OUTCOME MEASURES: Range of flexion-extension, lateral bend, and axial rotation; distance covered; average instantaneous velocity and acceleration. RESULTS: Caregivers performing transfers using the RATD as compared to when using the moble floor lift reported significantly smaller range of trunk flexion-extension, lateral bending, and axial rotation, and reported lower pelvic based distance covered and slower average instantaneous velocity and acceleration (P < 0.001). CONCLUSION: The design and usability of a RATD indicates design driven mobility advantages over clinical standard mobile floor lifts due to its ability to expand the workspace while further reducing risk factors for low back pain. While the concept is promising, further testing is required to address limitations and confirm the concept for clinical applications.

Preliminary evaluation of an automated robotic transfer assist device in the home setting.

PURPOSE: The purpose of this study was to examine the effects of six weeks of routine use of a novel robotic transfer device, the AgileLife Patient Transfer System, on mobility-related health outcomes, task demand, and satisfaction relative to previous transfer methods. MATERIALS AND METHODS: Six end users and five caregivers used the system in their homes for six weeks. Participants completed several surveys examining perceived demands related to preparing and performing a transfer and mobility-related health outcomes pre and post intervention. Participants were also asked about their satisfaction with using the technology compared to previous transfer methods. RESULTS: Both end users and caregivers reported reduction in perceived physical demand (p = 0.007) and work (p ≤ 0.038) when preparing for and performing a transfer. End users indicated that the device intervention had a positive impact, indicating some improvements to health-related quality of life as well as improved competence, adaptability, and self-esteem post-intervention. All participants were highly likely to recommend the technology to others. CONCLUSION: The AgileLife Patient Transfer System is a promising new form of transfer technology that may improve the mobility and mobility-related health of individuals with disabilities and their caregivers in home settings.Implications for rehabilitationRobotic transfer assistance reduced physical demand and work among end users and caregivers.The robotic device had a positive impact on some quality of life outcomes after 6 weeks of use.Users were highly likely to recommend the robotic transfer device to others.

Preliminary feasibility and acute physiological effects of a single session of upper limb vibration training for persons with spinal cord injury.

CONTEXT: Strong upper limb musculature is essential for persons with spinal cord injury (SCI) to operate a manual wheelchair and live independently. Targeted upper limb vibration may be a viable exercise modality to build muscle efficiently while eliminating some of the barriers associated with exercise for persons with SCI. OBJECTIVE: The purpose of this study was to assess preliminary feasibility of completing a single exercise session of upper limb vibration and compare the acute physiological effects to a single session of standard dumbbell resistance exercise. METHODS: Individuals with SCI performed seven upper limb exercises (1) isometrically using a vibrating dumbbell at 30 Hz for 60 s (n = 22) and (2) using a standard isotonic resistance protocol (n = 15). RESULTS: Nineteen (86.4%) of 22 participants were able to perform all vibration exercises at 30 Hz but hold time success rates varied from 33% (side flies and front raises) to 95% (internal rotation). No significant differences were found between vibration exercise and standard resistance protocol for blood lactate, power output, and heart rate (P > 0.05). Perceptions of the training were positive, with most participants (>70%) expressing interest to train with vibration in the future. CONCLUSIONS: Vibration training was not feasible for all participants, suggesting an individualized approach to starting weight and progression may be necessary. Similar acute physiological changes were seen between vibration exercise and standard resistance protocol, suggesting they could have similar benefits. Additional research is needed to determine if vibration exercise is feasible and beneficial to incorporate into a long-term training program.

Clinical and Ergonomic Comparison Between a Robotic Assisted Transfer Device and a Mobile Floor Lift During Caregiver-Assisted Wheelchair Transfers.

BACKGROUND: The robotic assisted transfer device was developed as an updated lift technology to reduce adjustments in posture while increasing capabilities offered by transfer devices. The purpose of this study was to compare the trunk biomechanics of a robotic assisted transfer device and a mechanical floor lift in the transfer of a care recipient by a caregiver during essential transfer tasks. METHODS: Investigators enrolled 28 caregiver/care recipient dyads to complete 36 transferring tasks. Surface electromyography for the back muscles and motion data for trunk range of motion were collected for selected surfaces, phase, and direction tasks using a robotic assisted transfer device and a mechanical floor lift. RESULTS: Robotic assisted transfer device transfers required significantly smaller range of trunk flexion (P < 0.001), lateral bend (P < 0.001), and axial rotation (P = 0.01), in addition to smaller distance covered (P < 0.001), average instantaneous velocity (P = 0.01), and acceleration (P < 0.001) compared with a mobile floor lift. The robotic assisted transfer device transfers required significantly smaller peak erector spinae (left: P = 0.001; right: P < 0.001) and latissimus dorsi (right: P < 0.001) and integrated erector spinae left (P = 0.001) and latissimus dorsi right (P = 0.01) electromyography signals compared with the floor lift. CONCLUSIONS: The robotic assisted transfer device provides additional benefits to mobile floor lifts which, coupled with statistically lower flexion, extension, and rotation, may make them an appealing alternative intervention.

Usability and task load comparison between a robotic assisted transfer device and a mechanical floor lift during caregiver assisted transfers on a care recipient.

INTRODUCTION: The RATD represents a novel methodology to reduce strain, manoeuvring, and cognitive load a caregiver experiences when conducting transfers on a mannequin. However, caregivers who used this new technology report suggested adjustments regarding the robot's human machine interface and shape as to improve transfer efficiency and comfort for care recipients. The purpose of this study was to test a redesigned RATD and compare its ergonomics during a transfer to those of a mechanical floor lift. METHODS: This was cross sectional protocol. As opposed to prior research which used a mannequin, caregivers in this study (N = 28) partnered with, and transferred, a mobility device user (N = 28) at three unique surfaces. Information about task demand and usability was collected from surveys after use of each device at each surface. RESULTS: Results indicated reduced physical demand (p = .004) and discomfort frequency (p = .01) in caregivers conducting the transfers with the RATD compared to the mechanical floor lift. Care recipients reported no significant differences between both transfer devices. Critiques with the interface, the harness and sling, and the robot's rigidity indicated more work is needed before introducing this technology to a larger market. Conclusions: The RATD represents a promising new intervention for transferring and handling care recipients who use wheelchairs. However, while caregivers report reduced physical demand and discomfort, more work is required to advance the ease of the human machine interface, the amount of space allowed for the robot to operate, and the ability of the care recipient to operate the technology independently.IMPLICATIONS FOR REHABILITATIONCaregivers report significant physical and mental stress while transferring clients in and out of a wheelchair.Clinical standard transfer equipment is limited in the space which it can be used.Robots, particularly those portable and powered, have the ability to not only make the transfer experience safer, but also expand the applications this equipment can provide.

Automating the Clinical Assessment of Independent Wheelchair Sitting Pivot Transfer Techniques.

BACKGROUND: Using proper transfer technique can help to reduce forces and prevent secondary injuries. However, current assessment tools rely on the ability to subjectively identify harmful movement patterns. OBJECTIVES: The purpose of the study was to determine the accuracy of using a low-cost markerless motion capture camera and machine learning methods to evaluate the quality of independent wheelchair sitting pivot transfers. We hypothesized that the algorithms would be able to discern proper (low risk) and improper (high risk) wheelchair transfer techniques in accordance with component items on the Transfer Assessment Instrument (TAI). METHODS: Transfer motions of 91 full-time wheelchair users were recorded and used to develop machine learning classifiers that could be used to discern proper from improper technique. The data were labeled using the TAI item scores. Eleven out of 18 TAI items were evaluated by the classifiers. Motion variables from the Kinect were inputted as the features. Random forests and k-nearest neighbors algorithms were chosen as the classifiers. Eighty percent of the data were used for model training and hyperparameter turning. The validation process was performed using 20% of the data as the test set. RESULTS: The area under the receiver operating characteristic curve of the test set for each item was over 0.79. After adjusting the decision threshold, the precisions of the models were over 0.87, and the model accuracies were over 71%. CONCLUSION: The results show promise for the objective assessment of the transfer technique using a low cost camera and machine learning classifiers.

Assessment of Wheelchair Propulsion Performance in an Immersive Virtual Reality Simulator.

Maneuvering a wheelchair is an important necessity for the everyday life and social activities of people with a range of physical disabilities. However, in real life, wheelchair users face several common challenges: articulate steering, spatial relationships, and negotiating obstacles. Therefore, our research group has developed a head-mounted display (HMD)-based intuitive virtual reality (VR) stimulator for wheelchair propulsion. The aim of this study was to investigate the feasibility and efficacy of this VR stimulator for wheelchair propulsion performance. Twenty manual wheelchair users (16 men and 4 women) with spinal cord injuries ranging from T8 to L2 participated in this study. The differences in wheelchair propulsion kinematics between immersive and non-immersive VR environments were assessed using a 3D motion analysis system. Subjective data of the HMD-based intuitive VR stimulator were collected with a Presence Questionnaire and individual semi-structured interview at the end of the trial. Results indicated that propulsion performance was very similar in terms of start angle (p = 0.34), end angle (p = 0.46), stroke angle (p = 0.76), and shoulder movement (p = 0.66) between immersive and non-immersive VR environments. In the VR episode featuring an uphill journey, an increase in propulsion speed (p < 0.01) and cadence (p < 0.01) were found, as well as a greater trunk forward inclination (p = 0.01). Qualitative interviews showed that this VR simulator made an attractive, novel impression and therefore demonstrated the potential as a tool for stimulating training motivation. This HMD-based intuitive VR stimulator can be an effective resource to enhance wheelchair maneuverability experiences.

Assessment of Muscle Activation of Caregivers Performing Dependent Transfers With a Novel Robotic-Assisted Transfer Device Compared With the Hoyer Advance.

OBJECTIVE: The purpose of this study was to compare muscle activity in caregivers while using a novel robotic-assisted transfer device (Strong Arm) to a clinical standard of care (Hoyer Advance). DESIGN: A quasi-experimental design was used in which 20 caregivers (33 ± 15 yrs old) performed transfers with three surfaces (toilet, bench, and shower chair) with the Strong Arm and Hoyer Advance. Transfer completion time (seconds), peak percentage surface electromyography (EMG), and integrated EMG of the bilateral erector spinae, latissimus dorsi, pectoralis major and anterior deltoid were measured. RESULTS: Caregivers required less transfer time when transferring from wheelchair to surface using the Hoyer Advance (P = 0.011, f = 0.39). For the lower back, significantly lower peak percentage EMGs were found using Strong Arm in 50% and for the integrated EMG in 25% of the cases, with the remaining cases showing no significant differences. For the shoulder, significantly lower peak percentage EMG values were found using Strong Arm in 19% of transfers and lower integrated EMG was found in 25% of transfers when using the Hoyer Advance, with the remaining cases showing no significant differences. CONCLUSION: Although back muscle activation during Strong Arm transfers is statistically, but not clinically, lower, additional features that couple with significantly lower muscle activation make it an alternative to the clinical standard for further research and possible clinical applicability.

Accessibility facilitators and barriers affecting independent wheelchair transfers in the community.

PURPOSE: The purpose of this study is to identify facilitators and barriers to wheelchair transfers in the community and to identify specific places and surfaces in the community where increasing transfer accessibility could enable greater participation. METHODS: This study enrolled 112 wheeled mobility device users who completed a survey describing barriers to independent transfers. Descriptive statistics (means, standard deviations, and percentages) were used to report the survey results. RESULTS: The majority of subjects (≥50% of the sample) who were impacted by the following features found them to be helpful while transferring: presence of transfer aids, presence of grab bars, large enough transfer surface size, storage space for a wheeled mobility device (WMD), large amounts of space and clearance for legs and feet, soft surfaces, and enough space next to the transfer surface. Ninety percent (90.5%) felt their participation was limited when surfaces higher than their WMD were encountered. Participants also reported feeling limited in their participation due to lack of transfer accessibility at a variety of community destinations, including medical facilities (35.1%), modes of transportation (38.5-52.1%), pools and hot tubs (45.4%), dressing rooms (50.0%), amusement parks (49.1%), and boating areas (52.1%). CONCLUSION: Improving accessibility for independent transfers in the community may support greater participation and lead to a better quality of life. Study findings provide insight into changes that would make the built environment more accessible and safer for wheelchair users who independently transfer.Implications for rehabilitationTransferring independently is one of the most physically demanding tasks for wheelchair users, and physical and environmental factors may affect transferability in the community.Identifying environmental facilitators and barriers to transfers may improve accessibility for wheelchair users, allowing for greater community participation, reduced risk of falls and injuries, and improvements to quality of life.

Person transfer assist systems: a literature review.

OBJECTIVE: Novel developments in the robotics field have produced systems that can support person wheelchair transfers, maximize safety and reduce caregiver burden. The purpose of this study was to identify and describe these systems, their usability (or satisfaction), the context for which they have been or can be used and how they have been evaluated to determine evidence for their effectiveness. METHOD: Available research on Person Transfer Assist Systems (PTAS) was systematically gathered using similar standards to the PRISMA guidelines. The search terms were derived from common terms and via exploring similar review articles. Initial search terms displayed 1330 articles and by using the inclusion/exclusion criteria 96 articles were selected for abstract review. After full- text reviewing 48 articles were included. RESULTS: 29 articles concerned research in robotic transfer systems, 10 articles used both ceiling and floor-mounted lifts and 9 articles used only floor-mounted lifts as an intervention/control group. The results of this analysis identified a few usability evaluations for robotic transfer prototypes, especially ones comparing prototypes to existing marketed devices. CONCLUSION: Robotic device research is a recent development within assistive technology. Whilst usability evaluations provided evidence that a robotic device will provide better service to the user, the sample number of subjects used are minimal in comparison to any of the intervention/control group articles. Experimental studies between PTASs are required to support technological advancements. Caregiver injury risk has been the focus for most of the comparison articles; however, few articles focus on the implications to the person.IMPLICATIONS FOR REHABILITATIONCeiling mounted lifts are preferred over floor-based lifts due to lower injury rates.Many robotic transfer systems have been developed; however, there is a paucity of quantitative and qualitative studies.Based on the results of this review, rehabilitation settings are recommended to use ceiling over floor assist systems, and it is recommended to provide training on using devices to assist with patient transfers to lower the risk of injuries.

Feasibility, acceptability, and preliminary efficacy of a handcycling high-intensity interval training program for individuals with spinal cord injury.

STUDY DESIGN: Pilot nonrandomized clinical trial. OBJECTIVES: To examine the feasibility, acceptability, and preliminary efficacy of performing handcycling high-intensity interval training (HIIT) for 6 weeks in wheelchair users with spinal cord injury. SETTING: Participant's home. METHODS: Participants completed pre- and postgraded exercise stress tests, exercise surveys and 6 weeks of handcycling HIIT. The HIIT program consisted of two weekly, 25 min supervised at-home sessions (2-3 min warm-up, then ten intervals of cycling with a ratio of 1 min work at 90% peak power output (PPO) to 1 min recovery at 0-20% PPO, then 2-3 min cool down). Real-time power output and heart rate were recorded via sensors and a bike computer. The sensor data were analyzed to evaluate training efficacy. RESULTS: Seven of the ten enrolled participants (70%) completed the study. All but one completed the required 12 sessions. The participants met at least 1 of the HIIT target intensity criteria in 76 out of 89 total sessions (85.4%) performed. Participants expressed a high level of enjoyment on the Physical Activity Enjoyment Scale, mean (SD) = 114.8 (11.3), and satisfaction with the overall experience. Five of the seven participants (71%) who completed the study felt an increase in endurance, function, and health. Objective physiological changes showed mixed results. CONCLUSIONS: Six weeks of handcycling HIIT appears to be safe, feasible and acceptable. A longer HIIT work interval may be needed to elicit significant physiological responses. Future investigation of the feasibility and efficacy of differing HIIT parameters is needed.

Rehabilitation professional and user evaluation of an integrated push-pull lever drive system for wheelchair mobility.

Wheeled mobility devices enable persons with limited mobility to maintain an independent lifestyle. Lever-drive propulsion options have been shown to increase wheeled mobility device efficiency while reducing physical strain on users. Despite these benefits, they have not been widely adopted for everyday use. Two novel lever-drive devices (RoScooter and RoTrike) provide an alternative to pushrim propulsion by using an integrated front-and-center push-pull lever mechanism. The objectives of this study were to assess the usability and performance of the lever-drive devices using both rehabilitation professional and user feedback. The study enrolled 17 rehabilitation professionals and 13 users who performed various mobility tasks to rate the performance of the RoScooter and RoTrike for ease of use, stability, safety, appearance, and comfort. Users were graded on their performance using a scoring system based on the Wheelchair Skills Test. Rehabilitation professionals suggested improvements in regard to adjustability, maneuverability, target population, and appearance, preferring the operations of the RoScooter to the RoTrike. Users reported that the devices were entertaining and easy to use, but improvements in adjustability, reversal methods, and operation options to appeal to a wider range of consumers are needed before lever-drive devices are suitable to replace or supplement current wheeled mobility devices.

An ergonomic comparison of three different patient transport chairs in a simulated hospital environment.

The purpose of this study was to compare caregiver muscle activation and joint angles between two ergonomic transport chairs designed to mitigate discomfort and safety risks associated with patient transport, the Stryker® Prime TC and the Staxi® Medical Chair, and a depot wheelchair. Twenty-three caregivers completed level walking and ramped tasks with each device and an 84 kg manikin. Surface electromyography for the upper extremities and back muscles and motion data were collected. The Staxi showed a statistical trend for higher wrist extensor and flexor carpi ulnaris activity compared to the Stryker chair (p ≤ 0.078) and greater wrist flexion than the Stryker and depot chairs (p ≤ 0.004). The depot chair showed greater peak trunk flexion than the Stryker chair (p = 0.004). Overall results suggest that ergonomic chair design may improve joint positioning of the trunk and elbows when operating patient transport chairs over level and ramped surfaces.

Start-up propulsion biomechanics changes with fatiguing activity in persons with spinal cord injury.

Objective: Shoulder pathology is a common condition in wheelchair users that can considerably impact quality of life. Shoulder muscles are prone to fatigue, but it is unclear how fatigue affects start-up propulsion biomechanics. This study determines acute changes in start-up wheelchair propulsion biomechanics at the end of a fatiguing propulsion protocol. Design: Quasi-experimental one-group pretest-postest design. Setting: Biomechanics laboratory. Participants: Twenty-six wheelchair users with spinal cord injury (age: 35.5 ± 9.8 years, sex: 73% males and 73% with a paraplegia). Interventions: Protocol of 15 min including maximum voluntary propulsion, right- and left turns, full stops, start-up propulsion, and rests. Outcome measures: Maximum resultant force, maximum rate of rise of applied force, mean velocity, mean fraction of effective force, and mean contact time at the beginning and end of the protocol during start-up propulsion. Results: There was a significant reduction in maximum resultant force (P < 0.001) and mean velocity (P < 0.001) at the end of the protocol. Also, contact time was reduced in the first stroke of start-up propulsion (P < 0.001). Finally, propelling with a shorter contact time was associated with a greater reduction in performance (maximum velocity) at the end of the protocol. Conclusion: There are clear changes in overground propulsion biomechanics at the end of a fatiguing propulsion protocol. While reduced forces could protect the shoulder, these reduced forces come with shorter contact times and lower velocity. Investigating changes in start-up propulsion biomechanics with fatigue could provide insight into injury risk.

Assessment of Usability and Task Load Demand Using a Robot-Assisted Transfer Device Compared With a Hoyer Advance for Dependent Wheelchair Transfers.

OBJECTIVE: Manual lifting can be burdensome for people who care for power wheelchair users. Although technologies used for dependent transfers are helpful, they have shortcomings of their own. This study compares the usability and task load demand of a novel robot-assisted transfer device to a clinical standard when performing dependent transfers. DESIGN: A cross-sectional study was conducted to assess caregivers (N = 21) transferring a 56-kg mannequin with the Strong Arm and Hoyer Advance at three transfer locations. Feedback was gathered through qualitative surveys. RESULTS: Usability was significant in multiple areas important for transfers. Caregiver fatigue and discomfort intensity were reduced, and the Strong Arm was preferred at the three transfer locations. Device ease and efficiency favored Strong Arm at two stations as was discomfort frequency. In addition, physical demand, frustration, and effort were significantly lower using Strong Arm compared with the Hoyer Advance. CONCLUSIONS: Compared with the Hoyer, participants favored Strong Arm for transfer usability and task load demand. However, further Strong Arm developments are needed.

Effects of grab bars and backrests on independent wheelchair transfer performance and technique.

OBJECTIVE: For individuals who rely on wheeled mobility devices for primary mobility, the ability to transfer independently greatly enhances participation in activities within and outside of the home. Nonlevel transfers are challenging and inevitable as not all surfaces in all settings can be made level with an individual's seat to floor height. The purpose of this study was to investigate the effects of two transfer aids, grab bars, and backrests, on the performance and quality of nonlevel transfers. METHODS: This study employed a repeated-measures design with transfer setup as the independent variable. Sixty-eight (53 men and 15 women) wheeled mobility device users performed level and nonlevel transfers to a bare surface, a surface with grab bars present, a surface with grab bars, and a backrest present. For each condition, participants were asked to transfer as high and as low as they could go while still performing an independent and safe transfer. The transfer assessment instrument was used to evaluate the quality of their transfer technique. RESULTS: Participants were able to transfer an absolute height up to 2.5 cm (1″) higher and lower when grab bars or grab bars and a backrest were present on the surface (p < 0.042) and 2.3 cm (~1″) higher relative to their wheelchair level seat high when grab bars were present on the surface (p < .001). Transfer technique significantly improved for both uphill and downhill transfers with the presence of grab bars and a backrest as shown by the transfer assessment instrument scores (p < 0.046). CONCLUSIONS: The presence of grab bars and a backrest on transfer surfaces may help mobility device users to achieve higher and lower absolute transfer heights and facilitate better transfer technique.

Upper-limb biomechanical analysis of wheelchair transfer techniques in two toilet configurations.

BACKGROUND: Using proper technique is important for minimizing upper limb kinetics during wheelchair transfers. The objective of the study was to 1) evaluate the transfer techniques used during toilet transfers and 2) determine the impact of technique on upper limb joint loading for two different toilet configurations. METHODS: Twenty-six manual wheelchair users (23 men and 3 women) performed transfers in a side and front wheelchair-toilet orientation while their habitual transfer techniques were evaluated using the Transfer Assessment Instrument. A motion analysis system and force sensors were used to record biomechanical data during the transfers. FINDINGS: More than 20% of the participants failed to complete five transfer skills in the side setup compared to three skills in the front setup. Higher quality skills overall were associated with lower peak forces and moments in both toilet configurations (-0.68 < r < -0.40, p < 0.05). In the side setup, participants who properly placed their hands in a stable position and used proper leading handgrips had lower shoulder resultant joint forces and moments than participants who did not perform these skills correctly (p ≤ 0.04). In the front setup, positioning the wheelchair within three inches of the transfer target was associated with reduced peak trailing forces and moments across all three upper limb joints (p = 0.02). INTERPRETATION: Transfer skills training, making toilet seats level with the wheelchair seat, positioning the wheelchair closer to the toilet and mounting grab bars in a more ideal location for persons who do sitting pivot transfers may facilitate better quality toilet transfers.