Immediate Biomechanical Implications of Transfer Component Skills Training on Independent Wheelchair Transfers

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.

Reliability of 3D Depth Motion Sensors for Capturing Upper Body Motions and Assessing the Quality of Wheelchair Transfers

Wheelchair users must use proper technique when performing sitting-pivot-transfers (SPTs) to prevent upper extremity pain and discomfort. Current methods to analyze the quality of SPTs include the TransKinect, a combination of machine learning (ML) models, and the Transfer Assessment Instrument (TAI), to automatically score the quality of a transfer using Microsoft Kinect V2. With the discontinuation of the V2, there is a necessity to determine the compatibility of other commercial sensors. The Intel RealSense D435 and the Microsoft Kinect Azure were compared against the V2 for inter- and intra-sensor reliability. A secondary analysis with the Azure was also performed to analyze its performance with the existing ML models used to predict transfer quality. The intra- and inter-sensor reliability was higher for the Azure and V2 (n = 7; ICC = 0.63 to 0.92) than the RealSense and V2 (n = 30; ICC = 0.13 to 0.7) for four key features. Additionally, the V2 and the Azure both showed high agreement with each other on the ML outcomes but not against a ground truth. Therefore, the ML models may need to be retrained ideally with the Azure, as it was found to be a more reliable and robust sensor for tracking wheelchair transfers in comparison to the V2.

The influence of shoulder pain and fear of falling on level and non-level transfer technique

BACKGROUND

Level and non-level transfers are essential tasks of daily living for wheelchair users. Minimal research has examined the role of shoulder pain and fear of falling on transfer quality. The purpose of this study is to (1) examine the association between shoulder pain, fear of falling (FoF) and transfer quality and (2) explore the feasibility of assessing non-level transfers to-and-from the floor.

METHODS

Cross-sectional design was used to explore shoulder pain, FoF, and transfer quality in 30 manual wheelchair users (aged 18-42; 15 males). Participant demographic information (age, sex, race, disability, and years using wheelchair), Spinal Cord Injury-Fall Concern Scale (SCI-FCS), and Wheelchair User Shoulder Pain Index (WUSPI) was collected. Three types of transfers: (1) level, (2) uphill, and (3) floor-to-table were graded by a trained researcher using the Transfer Assessment Instrument (TAI) 3.0. Kruskal-Wallis test was used to determine differences in transfer quality based on condition. Spearman correlation was used to determine associations between demographic data, WUSPI, SCI-FCS, and transfer quality scores.

RESULTS

All participants safely completed the uphill non-level transfer; 27 safely completed the floor-to-table non-level transfer. Statistical analysis revealed no difference in TAI score across transfer conditions. Spearman correlation revealed a significant correlation between WUSPI and SCI-FCS scores (r = .68, P = .01) and WUSPI and uphill TAI scores (r = -.45, P = .01).

CONCLUSION

Increases in shoulder pain are related to decreased uphill transfer quality and increased FoF. Non-level transfers to-and-from the floor are feasible within clinical or laboratory settings.

Prevalence of lateral epicondylosis in veteran manual wheelchair users participating in adaptive sports

Objective: Determine the prevalence of lateral epicondylosis (LE) of the dominant elbow in manual wheelchair users based on ultrasound assessment and physical exam.Design: Prospective, cross-sectional.Setting: National Veteran Wheelchair Games 2018 and 2019 (event medical services).Participants: Manual wheelchair users who attended the National Veteran Wheelchair Games (n = 87).Interventions: Participants completed a questionnaire then underwent an ultrasound assessment and a physical exam of their dominant arm evaluating for common extensor tendinopathy (CET) or clinically LE.Main Outcome Measure: Prevalence of CET diagnosed by ultrasound criteria was compared with other diagnostic criteria with MaNemar test for paired binary data.Results: Forty-six percent (N = 40) of participants met diagnostic criteria for CET by ultrasound assessment and 17% (N = 15) of participants met criteria for LE based on physical exam. These values are dramatically higher than what has been reported in the able-bodied population where the prevalence is estimated to be <2%. Age and number of years of wheelchair use were significant predictors of ultrasound diagnosis of LE (P = 0.02, 95% confidence interval [CI] 1.01-1.11) and (P = 0.05, 95% CI 1.00-1.09), respectively. Association analysis based on odds ratio and CI found no association between ultrasound findings suggestive of LE with regular adaptive sport participation greater than 1.5 h per week.Conclusion: Compared to able-bodied population, there is an increased prevalence of both CET and LE in manual wheelchair users based on either ultrasound assessment or physical exam. CET is associated with increased age and increased years using a manual wheelchair. There is no association between the diagnosis of LE and participation in adaptive sport.

Treatment of shoulder pain in people with spinal cord injury who use manual wheelchairs: a systematic review and meta-analysis

STUDY DESIGN

Systematic review and meta-analysis OBJECTIVES: The objective was to summarise prior research regarding the efficacy of active physiotherapy interventions and prevention strategies on shoulder pain, decreased physical function and quality of life in people with a spinal cord injury (SCI).

METHODS

A systematic literature search was conducted in CENTRAL, EMBASE (via Ovid), CINAHL and MEDLINE (via Ovid). Randomised controlled trials investigating effects of active physiotherapy interventions on shoulder pain, physical function and quality of life were included. Further, prospective cohort studies investigating effects of active physiotherapy interventions in prevention of shoulder pain and reduced physical function were included. Mean difference (MD) for pain (15 items on a 0-10 scale) and standardised mean difference (SMD) for physical function were summarised in a random effects meta-analysis.

RESULTS

Four studies on treatment (totalling 167 participants), and no studies on prevention were included. Significant and clinically meaningful improvements on shoulder pain (MD 19.06, 95% CI 5.72-32.40; I² = 65%) (scale 0-150) and physical function (SMD 0.61, 95% CI 0.27-0.94; I² = 0%) were found for active physiotherapy interventions. Only one study included quality of life, making meta-analysis inappropriate.

CONCLUSIONS

Evidence from a sparse number of studies supports active physiotherapy interventions to decrease shoulder pain and increase physical function in people with SCI who use a manual wheelchair. No studies met the criteria for prevention, highlighting a lack of research investigating prevention of shoulder pain and decreased physical function and quality of life.

Effectiveness of a Web-Based Direct-to-User Transfer Training Program: A Randomized Controlled Trial

OBJECTIVE

To determine the effectiveness of a web-based, direct-to-user transfer training program in improving transfer quality and maintaining improvements for up to 1 month after training as compared with a control group.

DESIGN

Randomized controlled trial with participants randomized to an immediate intervention group (IIG) or waitlist control group (WLCG) that received the training after a 6-month delay.

SETTING

Wherever the participants accessed the web-based training, likely the home environment.

PARTICIPANTS

Convenience sample of full-time wheelchair users (N=72; IIG, n=34; WLCG, n=38 for between-group analysis, n=48 for combined within-group analysis) with spinal cord injury or disorder who were able to independently perform a lateral scoot transfer.

INTERVENTIONS

Self-paced, web-based transfer training module.

MAIN OUTCOME MEASURES

Transfer Assessment Instrument Questionnaire (TAI-Q) score at baseline, 1 month, and 6 months postbaseline (WLCG only), immediately posttraining, and 1 month posttraining. The TAI-Q is an 18-item self-assessment that covers several aspects of a quality transfer.

RESULTS

The IIG significantly increased particpants' baseline TAI-Q score from 6.91±0.98 to 7.79±1.12 (P<.001) by 1 month posttraining. The WLCG also increased from baseline to the 1-month postbaseline assessment (from 6.52±1.13 to 7.00±1.09; P=.014), potentially from learning effects secondary to self-assessment with the TAI-Q. The extent of change over time did not differ significantly between the IIG and WLCG from baseline to 1 month (P=.169). However, significant improvements in TAI-Q scores were still evident after the training for the WLCG (P<.001). Those with a lower pretraining TAI-Q score and more shoulder pain were most likely to benefit from the training.

CONCLUSIONS

Repeated TAI-Q self-assessments likely contributed to improved transfer quality, with web-based training having an additive effect. Wheelchair users are likely to benefit from transfer training and self-assessment of transfer quality in their home environments. This has the potential to decrease injury risk while avoiding barriers to in-person training.

Intra- and Interrater Reliability of Remote Assessment of Transfers by Wheelchair Users Using the Transfer Assessment Instrument (Version 4.0)

OBJECTIVE

To evaluate the reliability, standard error of measurement, minimum detectable change, and item-level consistency of the Transfer Assessment Instrument (TAI) version 4.0 when used to evaluate transfer quality remotely.

DESIGN

Participants transferred from their wheelchair to a mat table (transfer 1), repeated this after a 10-minute delay to assess intrarater reliability (transfer 2), and repeated this 1-2 days later to assess test-retest reliability (transfer 3). Each transfer was scored in person by 4 raters and asynchronously by a remote clinician rater.

SETTING

2017 National Veterans Wheelchair Games.

PARTICIPANTS

Convenience sample of 44 full-time wheelchair users (N=44).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

TAI total score, subscores (wheelchair setup, body setup, flight/landing), and item scores (15 items).

RESULTS

Moderate to excellent reliability was found when scoring remotely for TAI total and subscores for intrarater (intraclass correlation coefficient (ICC(3,1)=0.687-0.854), test-retest (ICC(3,1)=0.695-0.836), and interrater reliability (ICC(3,5)=0.746-0.962). Remote rater total score and flight/landing subscore were greater (indicating higher transfer quality) compared to the average in-person raters (P=.021 and P=.005, respectively). There were no differences between transfers 1-3 in remote rater scores. Item-level percentage agreement between the remote rater and in-person exceeded the 75% cutoff for clinical utility for all items.

CONCLUSIONS

The TAI is a reliable outcome measure for assessing transfer technique remotely.

Concurrent Validity and Reliability of the Transfer Assessment Instrument Questionnaire as a Self-Assessment Measure

Objectives

To evaluate the psychometric properties of the Transfer Assessment Instrument Questionnaire (TAI-Q), a self-assessment measure to evaluate transfer quality compared with clinician-reported measures.

Design

Participants self-assessed transfers from their wheelchair to a mat table using the TAI-Q. For session 1, participants self-assessed their transfer both before and after reviewing a video of themselves completing the transfer (session 1). Self-assessment was completed for another transfer after a 10-minute delay (session 2, intrarater reliability) and after a 1- to 2-day delay (session 3, test-retest reliability). Self-assessment was compared with a criterion standard of an experienced clinician scoring the same transfers with the Transfer Assessment Instrument (TAI) version 4.0 (concurrent validity).

Setting

2017 National Veterans Wheelchair Games.

Participants

Convenience sample of full-time wheelchair users (N=44).

Interventions

Not applicable.

Main Outcome Measures

TAI-Q and TAI.

Results

After video review of their transfer, acceptable levels of reliability were demonstrated for total TAI-Q score for intrarater (intraclass correlation [ICC], 0.627) and test-retest reliability (ICC, 0.705). Moderate to acceptable concurrent validity was demonstrated with the TAI (ICC, 0.554-0.740). Participants tended to underestimate the quality of their transfer (reported more deficient items) compared with the TAI. However, this deficit decreased and reliability improved from pre-video review to post-video review and from session 1 to session 2. The minimum detectable change indicated that a change of 1.63 to 2.21 in the TAI-Q total score is needed to detect a significant difference in transfer skills.

Conclusions

When paired with video review, the TAI-Q demonstrates moderate to acceptable levels of reliability and validity for the total score. Self-assessment was completed quickly (<5min) and could help to potentially screen for deficiencies in transfer quality and opportunities for intervention.

Does the setting matter? Observing wheelchair transfers across different environmental conditions

The setting in which wheelchair transfers are performed can affect the difficulty and the risks associated with completion. This article presents results from an observational study involving 13 wheelchair users performing independent transfers across four settings. The aim is to understand how the environment affects how different types of independent transfers are performed. Descriptive analysis was performed alongside an objective assessment using the Transfer Assessment Instrument (TAI). The perceived difficulty reported after each transfer was also collected. Two participants exhibited radically different transferring techniques in different scenarios. Additionally, the transferring scenario was found to significantly affect the perceived difficulty of sitting transfers (toilet 2.17 ±.88; bed 1.47 ±.65, p =.001; car 1.63 ±.82, p =.012) and standing transfers (car 3.5 ±.71; bed 1 ± 0, p =.03; toilet 1 ± 0, p =.03), and the TAI score attributed to sitting pivot with use of a transfer board (couch 4.3 ±.88; bed 6.93 ± 1.29, p =.022; car 7.13 ± 1.32, p =.018). Overall, environmental constraints can lead to major technique changes and, more often, to different positioning of hands and feet which could impact the transfer's biomechanics.

Novel lateral transfer assist robot decreases the difficulty of transfer in post-stroke hemiparesis patients: a pilot study

PURPOSE

The purpose of this study was to clarify whether the novel lateral transfer assist robot facilitates easier transfers compared with a wheelchair in post-stroke hemiparesis patients.

METHODS

This cross-sectional study enrolled 20 post-stroke hemiparesis patients, and the task difficulty of transfers was compared between a wheelchair and lateral transfer assist robot. All participants were asked to transfer from either wheelchair or lateral transfer assist robot to a platform table and back. The primary outcome was the transfer score of the Functional Independence Measure. The secondary outcome was the time required for transfer.

RESULTS

The transfer score of the Functional Independence Measure was significantly higher with lateral transfer assist robot than with wheelchair (p < .001). The transfer times from these devices to a platform table and back showed no significant differences (to device from platform table: 7.8 s, lateral transfer assist robot vs 7.6 s, wheelchair, p > .05: device to platform table: 7.1 s, lateral transfer assist robot vs 8.0 s, wheelchair, p > .05).

CONCLUSIONS

Transfer with a lateral transfer assist robot is easier than with wheelchair and facilitates independence in post-stroke hemiparesis patients.IMPLICATIONS FOR REHABILITATIONTransfer skill influences the functional independence and quality of life of a wheelchair userA novel structural mobility device-the lateral transfer assist robot (LTAR)-can facilitate transfersThe LTAR could improve the degree of independence for transfers than the wheelchair, without any time loss, in post-stroke hemiparesis patientsThe LTAR could potentially reduce the risk for falls in various medical and care facilities.

A pilot investigation of anterior tilt use among power wheelchair users

PURPOSE

To examine the influence of use of the anterior tilt-in-space power seat function on performance of functional activities, physical health, and user satisfaction on among power wheelchair users.

MATERIALS AND METHODS

Ten full-time power wheelchair users with a seat elevator on their current chair participated in a mixed-methods, repeated measures study. At Visit 1 participants completed the Wheelchair Outcome Measure, Functional Mobility Assessment, Wheelchair Users Shoulder Pain Index, Fatigue Severity Scale, and the Spinal Cord Injury Secondary Conditions Scale. Physical assessments were performed to examine transfer quality (transfer assessment instrument), functional reach, activities of daily living (performance assessment of self-care skills), seated balance (function in sitting test), spasticity, respiratory function, and speech production. Approximately 3 days later (Visit 2), participants were trained on use and provided a power wheelchair with anterior tilt to trial for two weeks. After two weeks (Visit 3), the Visit 1 protocol was repeated and a semistructured interview conducted.

RESULTS

Participants lived with disabilities of cerebral palsy, spinal muscular atrophy and multiple sclerosis. With use of anterior tilt, significant improvements were seen among safety of meal preparation, p = 0.033, d_z = 0.91 and functional reach in the vertical direction, p = 0.000, d_z = 2.62. Subjectively, participants found anterior tilt helpful in performance of reaching tasks in but found the safety equipment restrictive.

CONCLUSION

Preliminary results indicate that use of the anterior tilt may help to improve performance of functional activities. Additional research is needed to examine the long-term influence of the technology.Implications for rehabilitationThe anterior tilt seat function changes the seat angle orientation in relation to the ground in the sagittal plane and angles the seat forward. As a result, the individual using the assistive technology is positioned in a semistanding position.Preliminary results of this study indicate that with use of anterior tilt, safety of meal preparation and functional reach in the vertical direction significantly improved. Subjectively, participants found anterior tilt helpful in performance of reaching tasks but found the safety equipment restrictive.Additional research is needed to examine the long-term influence of anterior tilt on functional activities, physical health and user satisfaction on among a large and diverse group of power wheelchair users.

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.

Reliability and Validity of the Revised Transfer Assessment Instrument

Background: Proper transfer technique is associated with improved biomechanics and decreased pain and pathology. However, many users do not use proper technique, and appropriate assessment and training are needed to address these deficits. The transfer assessment instrument (TAI) 4.0 was designed to meet those needs and improve on past versions by removing the need for clinician training, shortening administration time, and simplifying question content. Objectives: Evaluate the psychometric properties of the TAI 4.0. Methods: A convenience sample of full-time wheelchair users was scored on multiple transfers by four raters to assess interrater, intrarater, and test-retest reliability and concurrent validity of the TAI 4.0. Each user also was scored using a visual analog scale (VAS). Results: For 44 participants, the mean TAI 4.0 and VAS across all transfers were 7.58 ± 1.12 and 7.44 ± 1.78, respectively, and scores were significantly correlated (r = 0.52-0.7). VAS scores were more strongly influenced by the flight/landing and body setup phases of the transfer. There were no significant associations between TAI 4.0 score and demographics. Intraclass correlation coefficients (ICC) ranged from 0.80 to 0.85 for interrater reliability, 0.60 to 0.76 for intrarater reliability, and 0.55 to 0.76 for test-retest reliability. The minimum detectable change (MDC) for the total score ranged from 1.02 to 1.30. Conclusion: The TAI 4.0 provides reliable and valid quantitative assessment of an individual's transfer without the need for comprehensive training, as is the case with the TAI 3.0. The tool can be completed in 3 minutes (average) in a clinical setting with only a ruler and goniometer.

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.