Trunk and upper extremity kinematics during sitting pivot transfers performed by individuals with spinal cord injury

Kinematic analysis of preparation for transferring from wheelchair to bed

This study aimed to clarify the kinematics, particularly of the shoulder and hip joints, during preparation for manual wheelchair-to-bed transfer (i.e. when flipping up the arm and foot supports). This cross-sectional study included 32 able-bodied individuals. The kinematics of the shoulder and hip joints when the arm and foot supports were flipped up of manual wheelchair, were evaluated using a markerless inertial sensor-based motion capture system. We found that flipping the arm support upwards involved a large amount of abduction, internal and external rotation, flexion, and extension at the shoulder joint, whereas flipping the foot support upwards involved a large amount of flexion at the hip joint. The findings suggest that it is necessary to consider the range of motion required to flip up the arm and foot supports of manual wheelchairs, particularly in those with limited shoulder and hip range of motion such as older people, neuromuscular disorders, and orthopedic disorders.

Interventions focusing on learning pre-transfer wheelchair manipulation in a patient with severe Alzheimer's disease: a case report

BACKGROUND

Independence of transfer is important for the daily activities of wheelchair users. A critical step in performing this transfer includes a pre-transfer wheelchair manipulation, and patients with Alzheimer's disease (AD) experience difficulties in learning these tasks. In this report, we present the results of a treatment focused on learning pre-transfer wheelchair manipulation and its learning course in a patient with severe AD.

CASE DESCRIPTION

The patient was a 92-year-old woman with severe AD during hospitalization in a long-term care ward. Since her cognitive function was highly compromised, she required assistance for pre-transfer wheelchair manipulation. Physiotherapists implemented a treatment plan that incorporated post-behavioral praise into a practice combining errorless learning and spaced retrieval training for pre-transfer wheelchair manipulation.

OUTCOMES

The patient was able to accurately perform pre-transfer wheelchair manipulation in the seventh treatment session and achieved transfer independence after 12 physiotherapy sessions.

CONCLUSION

This case report suggests that practicing combined errorless learning, spaced retrieval training, and post-behavioral praise was helpful as a treatment modality for an individual with severe AD for wheelchair manipulation learning before transfer.

The associations of functional independence and quality of life with sitting balance and wheelchair skills among wheelchair users with spinal cord injury

CONTEXT/OBJECTIVE

To examine the associations of functional independence and quality of life (QOL) with sitting balance and wheelchair skills among individuals living with Spinal Cord Injury (SCI) who use a wheelchair full time.

METHODS

Secondary data analysis of a total of 59 wheelchair users living with SCI. Eighteen individuals were included in all analyses involving sitting balance. Demographics information and characteristics of SCI were collected through a survey. Participants reported their wheelchair skills performance, confidence, and capacity; functional independence; and QOL using the Wheelchair Skills Test Questionnaire (WST-Q) 5.0, Spinal Cord Independence Measure (SCIM III), and World Health Organization QOL (WHOQOL-BREF), respectively. Sitting balance was assessed remotely using the Function in Sitting Test (FIST). Correlations between variables were analyzed using the Spearman rank correlation test.

RESULTS

All the measures of SCIM III (total, selfcare, and mobility) correlated with the FIST (ρ = 0.52-0.66, p < 0.01 and p < 0.05). SCIM III-Mobility correlated with WST-performance, capacity, and confidence (ρ = 0.38-0.51, p < 0.01). WHOQOL-physical health and environment significantly correlated with WST-capacity and confidence (ρ = 0.26-0.33, p < 0.05). The FIST, WST-Performance, and level of injury did not correlate with any WHOQOL domain.

CONCLUSIONS

Lower functional independence and mobility are associated with poor sitting balance and poor wheelchair skills. Higher QOL may be associated with higher wheelchair skills. Future research is warranted to examine these relationships longitudinally to establish causality.

Upper limb electromyographic analysis of manual wheelchair transfer techniques in individuals with spinal cord injury: A systematic review

BACKGROUND AND PURPOSE

The objective of this study is to determine the upper limb muscle electromyographic (EMG) activity required during various manual wheelchair transfers in the population of spinal cord injury (SCI).

METHODS

This review included observational studies reporting the (EMG) activity of upper limb muscles during wheelchair transfers in people with SCI. We searched electronic databases and reference lists of relevant literature between 1995 and March 2022 with English language limits, yielding 3870 total articles. Two independent researchers performed data extraction and conducted quality assessment using two checklists, the Modified Downs and Blacks and National Heart, Lung, and Blood Institute for observational cohort and cross-sectional studies.

RESULTS

After eligibility screening, seven studies were included in this review. The sample size ranged from 10 to 32 participants aged 31-47 years. They assessed four types of transfers and mostly evaluated six upper limb muscles were biceps, triceps, anterior deltoid, pectoralis major, latissimus dorsi and ascending fibres of the trapezius. The peak EMG value indicated that muscle recruitment varied in both upper limbs according to the task demand, and the highest activity was seen during the lift-pivot transfer phase. Because of the data heterogeneity, a meta-analysis of study results was not feasible.

CONCLUSION

There were various ways of reporting the upper limb EMG muscle activity profile across all the included studies with a limited sample size. The crucial role of upper limb muscles during different types of manual wheelchair transfers was interpreted in this review. This is essential for predicting functional independence of individuals with SCI and warranting optimal rehabilitation strategies for wheelchair transfer skills.

Reliability of home-based remote and self-assessment of transfers using the Transfer Assessment Instrument among wheelchair users with spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To evaluate the reliability of home-based remote and self-assessment of transfer quality using the Transfer Assessment Instrument (TAI) among wheelchair users with spinal cord injury (SCI).

SETTING

Participant's home environment.

METHODS

Eighteen wheelchair users with SCI transferred from their wheelchair to a surface of their choice (bed, sofa, or bench) in their homes. During a live video conference, the transfer was recorded and evaluated live using the TAI (rater 1). Participants completed a self-assessment of their transfer using the TAI- questionnaire (TAI-Q). Two additional raters (raters 2 & 3) completed asynchronous assessments by watching recorded videos. Interrater reliability was assessed using Intraclass Coefficient Correlations (ICC) to compare rater 1 with the average of raters 2 & 3 and TAI-Q. Intrarater reliability was assessed by rater 1 completing another TAI by watching the recorded videos after a 4-week delay. Assessments were compared using paired sample t-tests and level of agreement between TAI scores was evaluated using Bland-Altman plots.

RESULTS

Moderate to good interrater and good intrarater reliability were found for the total TAI score with ICCs: 0.57-0.90 and 0.90, respectively. Moderate to good intrarater and interrater reliability were found for all TAI subscores (ICC: 0.60-0.94) except for interrater reliability of flight/landing which was poor (ICC: 0.20). Bland-Altman plots indicate no systematic bias related to the measurement of error.

CONCLUSIONS

The TAI is a reliable outcome measure for assessing the wheelchair and body setup phases of home-based transfers remotely and through self-assessment among individuals with SCI.

Policy Analysis on Power Seat Elevation Systems

In the early 2000s the Centers for Medicare and Medicaid Services determined that power seat elevation systems did not meet the definition of durable medical equipment, and therefore are non-covered items. Yet, power seat elevation systems are covered by other funding sources, and many power wheelchair users utilize these systems regularly when performing tasks such as transferring, reaching, and looking at objects in environments designed for ambulatory people. Adjusting for height when performing these tasks may reduce the onset of pain and comorbidities. To improve access to power seat elevation systems, a clinical team of 4 Clinician Task Force members investigated applicable literature, compiled evidence, and evaluated existing policies to explain the medical nature of power seat elevation systems as a part of a greater interprofessional effort. This manuscript aims to analyze Medicare's policy decision that power seat elevation systems are not primarily medical in nature using Bardach's 8-step framework. As a special communication, this will inform health care professionals of the medical nature of power seat elevation systems and the evidence-based conditions under which power wheelchair users may need power seat elevation systems, as well as empower clinicians to engage in policy directives to affect greater change.

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.

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.

Reliability and validity of the function in sitting test among non-ambulatory individuals with spinal cord injury

Context: Trunk impairment among non-ambulatory individuals with spinal cord injury (SCI) reduces the ability to maintain a functional sitting position and perform activities of daily living. Measuring functional sitting balance is complex and difficult in a clinical setting. The function in sitting test (FIST) is a clinical measure that includes the assessment of all the components of sitting balance. The purpose of this study is to assess the reliability and validity of the 14-item FIST among non-ambulatory individuals with SCI. Participants: Twenty-six individuals with chronic SCI. Outcome measures: Participants were evaluated with the FIST, the modified Functional Reach Test (lateral and forward mFRT) and a posturography assessment (virtual time to contact - VTC). The FIST was re-assessed during a second study visit 12 weeks later. Test-retest reliability was evaluated using intraclass coefficient correlation (ICC), the minimal detectable change (MDC) was calculated and the internal consistency reliability was assessed using Cronbach's coefficient-α. Concurrent validity of the FIST was also tested with the mFRT and the VTC. Results: Test-retest reliability was found to be excellent (ICC = 0.95) with a MDC of 4. The internal consistency was satisfactory (0.81). Moreover, the FIST correlates with the lateral mFRT (r = 0.64, P = 0.001) but not with the forward mFRT and the VTC. Conclusion: These observations provide evidence that the FIST is a reliable clinical measure with partially established validity for non-ambulatory individuals with SCI. Further studies are needed to strengthen the validity of the FIST and explore this measure in a larger sample.

Movement Coordination During Humeral Elevation in Individuals With Newly Acquired Spinal Cord Injury

Humeral elevation is a critical motion for individuals who use a manual wheelchair given that, in a typical day, wheelchair users reach overhead 5 times more often than able-bodied controls. Kinematic analyses in individuals with chronic spinal cord injury (SCI) have focused on weight-bearing tasks rather than overhead reaching. This technical report presents shoulder movement coordination during overhead reaching in individuals with newly acquired SCI. Eight volunteers with acute SCI and 8 matched, uninjured controls participated. Three-dimensional kinematics were collected during seated, humeral elevation. Scapular and thoracic rotations during humeral elevation were averaged across repetitions. The linear relationship of scapular upward rotation to humeral elevation provided movement coordination analysis. Maximal elevation was reduced in SCI with increased thoracic kyphosis. Medium to large effect sizes were found at each elevation angle, with reduced scapular external rotation, posterior tilt, and increased thoracic kyphosis for those with SCI. The linear relationship occurred later and within a significantly (P = .02) smaller range of humeral elevation in SCI. Altered movement coordination, including a diminished linear association of scapular upward rotation and humeral elevation (scapulohumeral rhythm), is found with reduced maximal elevation and increased thoracic kyphosis during overhead reaching tasks in those with acute SCI.

Reliability of measurement of active trunk movement in wheelchair basketball players

The study aim was to assess the reliability to active trunk movements measurement in four sitting positions in wheelchair basketball players and to check their trunk movements in these positions. Eighteen volunteer wheelchair basketball athletes, with a minimum of five years’ training experience, were asked to perform the maximum range of active trunk movement in three planes in four sitting positions (in a sports wheelchair with straps, without straps, on a table with feet on the floor, on a table without foot support). The range of movement was measured by the Kinect for Windows V2 sensor twice (with one-week interval). To assess the reliability, different statistical methods were used for each movement: significance of differences between the results (p-value), interclass correlation coefficient (ICC) and minimal detectable change (MDC). The limits of agreement analysis (LOA) were calculated. Differences between trunk movements in four positions were checked by the MANOVA (Wilk’s Lambda and ETA² were calculated if data were normally distributed). The significance level was set at α < .05. Friedman ANOVA and non-parametric Wilcoxon test with the Bonferroni correction were applied when data were not normally distributed. The significance level after Bonferroni correction was set at α < .013 (α = p/k, where p = .05, k–number of positions = 4). The measurement of active trunk movement in each plane was reliable (p > .05, no differences between the results, “very good”ICC, between .96-.99). In the position with straps, the trunk movement was significantly bigger than in other positions (p < .05), except for the position without straps (p > .05). The Kinect for Windows V2 sensor measured active trunk movement in a reliable manner and it can be recommended as a reliable tool for measuring trunk function. Utilizing straps by wheelchair basketball players increases their trunk movement.

Lateral Transfer Assist Robot (LTAR): Development of a proof-of-concept prototype

BACKGROUND

Falls during transfer to and from a wheelchair are associated with numerous problems. Factors responsible for difficulty in transferring include horizontal/vertical gaps between surfaces; obstacles, such as armrests; and complicated brake/footrests configurations before transferring. Moreover, controlling a wheelchair sufficiently close to the transfer surface within the confined home space is difficult.

OBJECTIVE

We described the design of the novel Lateral Transfer Assist Robot (LTAR) for solving problems during transfer. Furthermore, the effectiveness and usability of the robot were preliminary examined in healthy adults.

METHOD

The transfer problems and basic designs were organized. The effectiveness of the prototype was measured by three-dimensional motion analysis and questionnaire.

RESULTS

The prototype LTAR was developed. With just a push on a button, the footplate lowers to the floor and the seat and armrest lowers to the height of the seating surface to fill the gap between the surfaces. Using these features, users can transfer by simply shifting their buttocks sideways. Additionally, LTAR has omnidirectional wheels that help move it within a narrow space. The LTAR was confirmed to reduce the physical and subjective burden, except for maneuverability.

CONCLUSION

The LTAR was found to be effective for home use and reducing burden of transfer.

Advanced weight-bearing mat exercises combined with functional electrical stimulation to improve the ability of wheelchair-dependent people with spinal cord injury to transfer and attain independence in activities of daily living: a randomized controlled trial

STUDY DESIGN

Randomized controlled trial.

OBJECTIVE

To determine the effects of advanced weight-bearing mat exercises (AWMEs) with/without functional electrical stimulation (FES) of the quadriceps and gastrocnemius muscles on the ability of wheelchair-dependent people with spinal cord injury (SCI) to transfer and attain independence in activities of daily living (ADLs).

SETTING

An outpatient clinic, Iran.

METHODS

People with traumatic chronic paraplegia (N = 16) were randomly allocated to three groups. The exercise group (EX; N = 5) performed AWMEs of quadruped unilateral reaching and tall-kneeling for 24 weeks (3 days/week). Sessions were increased from 10 min to 54 min over the 24-week period. The exercise-FES group (EX + FES; N = 5) performed AWMEs simultaneously with FES of the quadriceps and gastrocnemius muscles. The control group performed no exercise and no FES (N = 6). The primary outcomes were the total Spinal Cord Independence Measure-III (SCIM-III) to reflect independence with ADL, and the sum of the four SCIM-III transfer items to reflect ability to transfer. There were six other outcomes.

RESULTS

The mean (95% CI) between-group differences of the four transfer items of the SCIM-III for the EX vs. control group was 1.8 points (0.2-3.4), and for the EX + FES vs. control group was 2 points (0.4-3.6). The equivalent differences for the total SCIM-III scores were 2.7 points (-0.6-6.0) and 4.1 points (0.8-7.4), respectively. There were no significant between-group differences for any other outcomes.

CONCLUSIONS

Advanced weight-bearing mat exercises improve the ability of wheelchair-dependent people with SCI to transfer and attain independence in ADL.

Impact of spasticity on transfers and activities of daily living in individuals with spinal cord injury

CONTEXT/OBJECTIVE

For persons with spinal cord injury, spasticity commonly interferes with activities of daily living such as transfers. Electromyography can be used to objectively measure muscle spasms during transfers, but how electromyographic measures relate to the impact spasticity has on life, or to clinically-rated spasticity, is unclear. We aimed to characterize relationships among spasm duration and magnitude, impact of spasticity on daily life, and a clinical measure of extensor spasticity, as well as to determine reliability of the electromyographic measures.

DESIGN

Participants (N=19) underwent electromyographic measurements of involuntary muscle activity (spasm duration and magnitude) evoked in quadriceps muscles during transfers on two days. Impact of spasticity on daily life was measured with the Spinal Cord Injury Spasticity Evaluation Tool. Clinically-rated spasticity severity was measured with the Spinal Cord Assessment Tool for Spastic reflexes.

RESULTS

No significant associations were found between impact of spasticity and spasm duration, spasm magnitude, or clinical extensor spasticity score. Absolute and normalized spasm duration were positively associated with clinical extensor spasticity score (rho=0.510-0.667, P < 0.05). Spasm measures during transfers had good to excellent day-to-day reliability (rho=0.656-0.846, P < 0.05).

CONCLUSIONS

Electromyographic and clinical measures of involuntary activity in the lower extremity do not significantly relate to perceived impact of spasticity on daily life. However, quadriceps spasm duration during transfers is related to clinically-rated extensor spasticity. Electromyography is a reliable method of quantifying quadriceps spasms during transfers. Future investigations should identify factors that influence the impact of spasticity on life, which may help direct treatment strategies to reduce problematic impact.

Understanding independent wheelchair transfers. Perspectives from stakeholders

Purpose: Transferring to and from the wheelchair is among the most important routine tasks for many wheelchair users. Transfers are also greatly affected by many personal and external factors. The purpose of this study is to investigate personal experiences, needs and concerns of wheelchair users in relation to wheelchair transfers performed in their everyday lives.Methods: A series of focus groups and interviews were carried out with 11 wheelchair users and 4 occupational therapists. Data were analysed using a hybrid deductive and inductive approach of thematic analysis.Results: The seven themes identified emphasize the importance and complexity of wheelchair transfers. Transfers were described as gateways to independence that grant access to life opportunities, and community participation. Nonetheless, transferring skills are difficult to acquire and the concept of correct technique, although really important, is often poorly defined. Wheelchair transfers can be further complicated by the characteristics of the individual, the presence of upper limb pain, fear of falling or the characteristics of the environment. Despite the importance of transfer training to improve safety and reduce the risk of overload injuries, only a few people receive dedicated advice from health professionals. Currently available assistive technologies were perceived as only partially successful in providing support to wheelchair users during the execution of transfers, especially when environmental constraints make the transfer more challenging.Conclusion: Due to their multifactorial nature, creating effective solutions to improve any aspect of wheelchair transfers will require a collaborative effort from users, clinicians, designers and other professionals.Implications for rehabilitationThe ability to transfer independently is extremely important for many wheelchair users and can affect not only their personal and social lives, but also the way they perceive themselves and are perceived by others.The use of a correct transferring technique plays an important role in reducing the effort required to complete a transfer and decreases the risk factors for both falls and upper limb injury development. Unfortunately, few wheelchair users have access to in-person training to develop transferring skills. The remaining people rely on a combination of peer observation, personal research and simple trial and error to figure out the movement strategies that better suit their needs.Currently available assistive technologies are perceived by wheelchair users as only partially successful in providing support during the execution of transfers. Transfer boards and other devices are often described as only useful for basic transfers and for individuals with reduced, but still sufficient, upper limb function.

Effect of corporal suspension and pendulum exercises on neuromuscular properties and functionality in patients with medullar thoracic injury

BACKGROUND

Traumatic spinal cord injury (TSCI) is one of the most devastating injuries that has a physical impact on patients. The CHORDATA® method involves suspension and pendulous exercises and has been clinically used to treat patients with TSCI. Although empirically used to treat neurological patients, there is no scientific evidence of the efficacy of this method.

PURPOSE

To evaluate the chronic effects of CHORDATA® method on torque, muscle activation, muscle thickness, and functionality in patients with traumatic spinal cord injury.

METHODS

Twenty-six male patients with medullar thoracic injury were randomly categorised into two groups: intervention group (n = 14) and control group (n = 12). Rehabilitation program comprised of 16 sessions of body suspension and pendulum exercises (twice/week). The maximal voluntary isometric trunk flexion and extension torques, muscle activation and thickness (external and internal oblique, rectus and transversus abdominis, longissimus, and multifidus muscles), and functionality (adapted reach test) were evaluated before and after of rehabilitation program.

FINDINGS

A significant increase was observed in maximal voluntary isometric torque (flexion, 58%; extension, 76%), muscle activation of the rectus abdominis muscle, and muscle thickness of all intervention group muscles, without changes in the control group. Compared to the pre-intervention period, the intervention group also showed improvement in functionality at post-intervention, but no such differences were noted in the control group.

INTERPRETATION

The corporal suspension and pendulum exercises training improved rectus abdominis muscle activation, trunk muscles structure and strength, and reaching capacity in medullar thoracic injury patients.

Use of a Low-Cost, Chest-Mounted Accelerometer to Evaluate Transfer Skills of Wheelchair Users During Everyday Activities: Observational Study

Background

Transfers are an important skill for many wheelchair users (WU). However, they have also been related to the risk of falling or developing upper limb injuries. Transfer abilities are usually evaluated in clinical settings or biomechanics laboratories, and these methods of assessment are poorly suited to evaluation in real and unconstrained world settings where transfers take place.

Objective

The objective of this paper is to test the feasibility of a system based on a wearable low-cost sensor to monitor transfer skills in real-world settings.

Methods

We collected data from 9 WU wearing triaxial accelerometer on their chest while performing transfers to and from car seats and home furniture. We then extracted significant features from accelerometer data based on biomechanical considerations and previous relevant literature and used machine learning algorithms to evaluate the performance of wheelchair transfers and detect their occurrence from a continuous time series of data.

Results

Results show a good predictive accuracy of support vector machine classifiers when determining the use of head-hip relationship (75.9%) and smoothness of landing (79.6%) when the starting and ending of the transfer are known. Automatic transfer detection reaches performances that are similar to state of the art in this context (multinomial logistic regression accuracy 87.8%). However, we achieve these results using only a single sensor and collecting data in a more ecological manner.

Conclusions

The use of a single chest-placed accelerometer shows good predictive accuracy for algorithms applied independently to both transfer evaluation and monitoring. This points to the opportunity for designing ubiquitous-technology based personalized skill development interventions for WU. However, monitoring transfers still require the use of external inputs or extra sensors to identify the start and end of the transfer, which is needed to perform an accurate evaluation.

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.

Effect of technique and transfer board use on the performance of wheelchair transfers

Transferring to and from the wheelchair seat is a necessary skill for many wheelchair users who wish to be independent of their everyday life. The performance of wheelchair transfers has been associated with the risk of falling and developing upper limb injuries. Both present a risk to the independence of the individual. Previous studies on wheelchair transfers have focused mainly on the analysis of sitting transfers performed by individuals with spinal cord injury, which only represent a small portion of the wider wheelchair users’ population. The purpose of this study is to investigate the effect of different transferring techniques (sitting, standing) and transfer board use on the ground reaction forces under the hands during transfer performance and transfer quality measured using the transfer assessment instrument (TAI). Sitting transfers displayed generally higher peak and mean reaction forces underneath both leading and trailing hands compared with the other techniques, but the difference was only significant between sitting and standing transfers. Standing transfers had significantly lower TAI scores compared with sitting transfer, potentially indicating a decreased level of safety associated with their performance. Transfer boards were only partially effective in reducing the weight born by the upper limbs and they caused only a minor reduction in the overall TAI score in comparison to sitting transfers.

End user evaluation of a Kneeling Wheelchair with "on the fly" adjustable seating functions

A "kneeling" ultralight wheelchair prototype has been developed that allows users to adjust seat position "on the fly" for different activities throughout the day. The wheelchair includes independent adjustment functions for rear seat height, front seat height ("kneeling") and backrest angle.  Aim: This work aimed to gather feedback about the wheelchair's functionality and performance through end user evaluation trials.  Methods: Eight manual wheelchair users evaluated the prototype Kneeling Wheelchair for a range of activities. User perspectives on parameters such as usability, comfort, stability and effectiveness were obtained through both open-ended and Likert-scale rating questions.  Results: Results indicate several potential benefits of the adjustment functions of the Kneeling Wheelchair. Rear seat height adjustment may facilitate a number of activities of daily living, as well as provide benefits for comfort and social interactions. Back rest adjustment may increase comfort and stability on slopes. Front seat height adjustment may be beneficial for transfers and conducting sustained low-to-the-ground activities. While benefits of this adjustment function were described by many participants, some struggled with usability of the kneeling mechanism and rated this function less favourably than the other two.  Conclusion: The findings of this study will inform future iterations of the Kneeling Wheelchair design and may spur future developments in wheeled mobility. In the long-term, it is anticipated that novel wheelchair solutions, such as the one described in this paper, may support improved health, quality of life and community participation for people with mobility impairments. Implications for rehabilitation Wheelchairs that allow users to easily adjust seat and backrest position "on the fly" to better suit different tasks throughout the day may provide benefits such as facilitating activities of daily living. A front seat height adjustment feature on a new wheelchair prototype may be beneficial for transfers and conducting sustained low-to-the ground activities. End user evaluations can provide valuable insight to direct future design modifications and innovation.

Anticipatory detection of turning in humans for intuitive control of robotic mobility assistance

Many wearable lower-limb robots for walking assistance have been developed in recent years. However, it remains unclear how they can be commanded in an intuitive and efficient way by their user. In particular, providing robotic assistance to neurologically impaired individuals in turning remains a significant challenge. The control should be safe to the users and their environment, yet yield sufficient performance and enable natural human-machine interaction. Here, we propose using the head and trunk anticipatory behaviour in order to detect the intention to turn in a natural, non-intrusive way, and use it for triggering turning movement in a robot for walking assistance. We therefore study head and trunk orientation during locomotion of healthy adults, and investigate upper body anticipatory behaviour during turning. The collected walking and turning kinematics data are clustered using the k-means algorithm and cross-validation tests and k-nearest neighbours method are used to evaluate the performance of turning detection during locomotion. Tests with seven subjects exhibited accurate turning detection. Head anticipated turning by more than 400-500 ms in average across all subjects. Overall, the proposed method detected turning 300 ms after its initiation and 1230 ms before the turning movement was completed. Using head anticipatory behaviour enabled to detect turning faster by about 100 ms, compared to turning detection using only pelvis orientation measurements. Finally, it was demonstrated that the proposed turning detection can improve the quality of human-robot interaction by improving the control accuracy and transparency.

Short-term influence of transfer training among full time pediatric wheelchair users: A randomized trial

OBJECTIVE/BACKGROUND

To describe a structured, short-term, transfer training intervention for full-time pediatric wheelchair users, investigate the impact of training on transfer skills, and to examine similarities and differences in response to training compared to those seen in adult wheelchair users.

DESIGN

Randomized clinical trial.

METHODS

Participants were first randomized into an intervention (IG) or control group (CG). After completing surveys and demographic intake forms, all participants performed two sets of level transfers (from wheelchair to bench and back to wheelchair = one set) at three time points. Each time point composed of two transfer sets were scored using the Transfer Assessment Instrument (TAI) and averaged to produce a final transfer score per time point. No feedback or training were given to participants prior to time points one and two however the IG received structured training prior to transfer assessment # 3. TAI scores were compared at transfer assessment #3 using a Mann-Whitney test.

OUTCOME MEASURES

Transfer Assessment Instrument (TAI) and Self-Perception Profile for Children (SPPC).

RESULTS

Intervention group participants demonstrated significant improvements among TAI scores (9.06 ± 1.01) compared to the control group (7.15 ± 1.67), P = 0.030, d = 1.385. No significant differences were found among SPPC scores.

CONCLUSION

Pediatric wheelchair users transfer skills were found to improve immediately after training with TAI score changes similar to those seen in adult wheelchair users after training. Such improvements may be a factor in long-term upper extremity preservation. Further testing is needed to examine the long-term impact of improved transfer skills.

Electrical Stimulation to Reduce the Overload in Upper Limbs During Sitting Pivot Transfer in Paraplegic: A Preliminary Study

Transfer is a key ability and allows greater interact with the environment and social participation. Conversely, paraplegics have great risk of pain and injury in the upper limbs due to joint overloads during activities of daily living, like transfer. The main goal of this study is to verify if the use of functional electrical stimulation (FES) in the lower limbs of paraplegic individuals can assist the sitting pivot transfer (SPT). The secondary objective is to verify if there is a greater participation of the lower limbs during lift pivot phase. A preliminary study was done with one complete paraplegic individual. Temporal parameters were calculated and a kinetic assessment was done during the SPT. The preliminary results showed the feasibility of FES for assisting the SPT.

Relationship between the duration and trunk inclination and hip angle during car transfer in individuals with tetraplegia

[Purpose] The purpose of the present study was to investigate the relationship between the duration of the car transfer (CT) movement and trunk inclination and hip angles during this movement in individuals with tetraplegia. [Subjects and Methods] Eleven adult males with C6 tetraplegia participated in this study. The CT movement was recorded from the passenger side of the car using a digital video camera. From the video, the duration and trunk inclination and hip joint angle were recorded, and correlation coefficients were calculated. [Results] No correlation was found between the trunk inclination angle and the duration of the CT movement. However, a significant correlation was found between the hip angle and the duration of the CT movement: when the duration was short, the hip flexion angle was substantial. [Conclusion] The trunk inclination angle probably showed no effect on the duration of the CT movement because the movement was performed in a limited space and because the trunk muscles of the subjects were paralyzed. In contrast, C6 tetraplegia enabled smooth CT by allowing for control of trunk inclination, such as placing the lower extremities in the car, whereby the pelvis backward tilt angle increased.

Upper limb joint kinetics of three sitting pivot wheelchair transfer techniques in individuals with spinal cord injury

STUDY DESIGN

Repeated measures design.

OBJECTIVE

This study compared the upper extremity (UE) joint kinetics between three transfer techniques.

SETTING

Research laboratory.

METHODS

Twenty individuals with spinal cord injury performed three transfer techniques from their wheelchair to a level tub bench. Two of the techniques involved a head-hips method with leading hand position close (HH-I) and far (HH-A) from the body, and the third technique with the trunk upright (TU) and hand far from body. Motion analysis equipment recorded upper body movements and force sensors recorded their hand and feet reaction forces during the transfers.

RESULTS

Several significant differences were found between HH-A and HH-I and TU and HH-I transfers indicating that hand placement was a key factor influencing the UE joint kinetics. Peak resultant hand, elbow, and shoulder joint forces were significantly higher for the HH-A and TU techniques at the trailing arm (P < 0.036) and lower at the leading arm (P < 0.021), compared to the HH-I technique.

CONCLUSION

Always trailing with the same arm if using HH-A or TU could predispose that arm to overuse related pain and injuries. Technique training should focus on initial hand placement close to the body followed by the amount of trunk flexion needed to facilitate movement.

Design and user evaluation of a wheelchair mounted robotic assisted transfer device

PURPOSE

The aim of this study is to describe the robotic assisted transfer device (RATD) and an initial focus group evaluation by end users. The purpose of the device is to aid in the transfers of people with disabilities to and from their electric powered wheelchair (EPW) onto other surfaces. The device can be used for both stand-pivot transfers and fully dependent transfers, where the person being transferred is in a sling and weight is fully on the robot. The RATD is fixed to an EPW to allow for its use in community settings.

METHOD

A functional prototype of the RATD was designed and fabricated. The prototype was presented to a group of 16 end users and feedback on the device was obtained via a survey and group discussion.

RESULTS

Thirteen out of sixteen (83%) participants agreed that it was important to develop this type of technology. They also indicated that user, caregiver, and robotic controls were important features to be included in the device.

CONCLUSIONS

Participants in this study suggested that they would be accepting the use of robotic technology for transfers and a majority did not feel that they would be embarrassed to use this technology.

Sitting tai chi improves the balance control and muscle strength of community-dwelling persons with spinal cord injuries: a pilot study

Objective. To investigate the effects of sitting Tai Chi on muscle strength, balance control, and quality of life (QOL) among survivors with spinal cord injuries (SCI). Methods. Eleven SCI survivors participated in the sitting Tai Chi training (90 minutes/session, 2 times/week for 12 weeks) and eight SCI survivors acted as controls. Dynamic sitting balance was evaluated using limits of stability test and a sequential weight shifting test in sitting. Handgrip strength was also tested using a hand-held dynamometer. QOL was measured using the World Health Organization's Quality of Life Scale. Results. Tai Chi practitioners achieved significant improvements in their reaction time (P = 0.042); maximum excursion (P = 0.016); and directional control (P = 0.025) in the limits of stability test after training. In the sequential weight shifting test, they significantly improved their total time to sequentially hit the 12 targets (P = 0.035). Significant improvement in handgrip strength was also found among the Tai Chi practitioners (P = 0.049). However, no significant within and between-group differences were found in the QOL outcomes (P > 0.05). Conclusions. Twelve weeks of sitting Tai Chi training could improve the dynamic sitting balance and handgrip strength, but not QOL, of the SCI survivors.

Effect of different hand positions on trunk and shoulder kinematics and reaction forces in sitting pivot transfer

[Purpose] The purpose of this study was to compare the changes in trunk and shoulder angles, and reaction forces under the two hands elicited by different hand base of support positions during sitting pivot transfer. [Subjects and Methods] Eighteen unimpaired subjects performed independent sitting pivot transfer. Subjects performed sitting pivot transfer between an initial seat to a target seat by only using their hands positioned at the same height as and lower than the seat position. Trunk and shoulder kinematics, and reaction forces on the trailing and leading hands were calculated. Mean peak joint angles and forces were compared between the hand positions using the pared t-test for the lift phase of the transfer. [Results] There were significant increases in the trunk angles of forward and lateral flexion, even though rotation decreased while transferring in the lower hand position. Increased shoulder flexion, anterior/posterior forces and reduced lateral forces were also shown. [Conclusion] Placing the hands of the supporting arms lower than the seat position during sitting pivot transfer was identified as having biomechanical advantages. Therefore, the lower hand position can be recommended as an effective and safe method for sitting pivot transfer by patients with spinal cord injury and can be utilized as a reference data for considering the appropriate height of aids for a wheelchair.

Reliability of dynamic sitting balance tests and their correlations with functional mobility for wheelchair users with chronic spinal cord injury

The purpose of this study is to develop a reliable and valid tool for measuring the dynamic sitting balance of wheelchair users with spinal cord injury. The balance tests were performed in nine patients with chronic spinal cord injury (average of 17.2 years postinjury) between levels C6 and L1, while they were sitting in their wheelchairs and on a standardized stool (unsupported sitting), twice, 7 days apart. Limits of stability (LOS) and sequential weight shifting (SWS) were designed in this study. The balance tests measured participants' volitional weight shifting in multiple directions within their base of support. Their mobility scores on the Spinal Cord Independence Measure III were correlated with the balance test results. The LOS results showed moderate to excellent test-retest reliability (intraclass correlation coefficients ranged from 0.673 to 0.990) for both the wheelchair and the unsupported sitting. The SWS results showed moderate to excellent reliability (intraclass correlation coefficients ranged from 0.688 to 0.952). The LOS results correlated significantly with the Spinal Cord Independence Measure III mobility scores only in case of unsupported sitting, but the SWS test results showed significant correlations in both sitting conditions. To sum up, the sitting LOS and SWS tests are reliable and valid tools for assessing the dynamic sitting balance control of patients with spinal cord injury.

The relationship between independent transfer skills and upper limb kinetics in wheelchair users

Transfers are one of the most physically demanding wheelchair activities. The purpose of this study was to determine if using proper transfer skills as measured by the Transfer Assessment Instrument (TAI) is associated with reduced loading on the upper extremities. Twenty-three wheelchair users performed transfers to a level-height bench while a series of forces plates, load cells, and a motion capture system recorded the biomechanics of their natural transferring techniques. Their transfer skills were simultaneously evaluated by two study clinicians using the TAI. Logistic regression and multiple linear regression models were used to determine the relationships between TAI scores and the kinetic variables on both arms across all joints. The results showed that the TAI measured transfer skills were closely associated with the magnitude and timing of joint moments (P < .02, model R(2) values ranged from 0.27 to 0.79). Proper completion of the skills which targeted the trailing arm was associated with lower average resultant moments and rates of rise of resultant moments at the trailing shoulder and/or elbow. Some skills involving the leading side had the effect of increasing the magnitude or rate loading on the leading side. Knowledge of the kinetic outcomes associated with each skill may help users to achieve the best load-relieving effects for their upper extremities.

Ascending curbs of progressively higher height increases forward trunk flexion along with upper extremity mechanical and muscular demands in manual wheelchair users with a spinal cord injury

High upper extremity (U/E) demands are required when manual wheelchair users (MWUs) with spinal cord injury (SCI) ascend curbs; this may contribute to the risk of developing U/E musculoskeletal impairments. The aim of this study was to compare movement strategies (kinematics), mechanical loads (kinetics) and muscular demand (EMG) at the non-dominant U/E among 15 MWUs with SCI when ascending curbs of 4 cm (3 trials), 8 cm (3 trials) and 12 cm high (3 trials) from a starting line set 3 m before the curb. Biomechanical data was collected during three trials for each height. The curb ascent task was divided into three adjustment phases: caster pop, rear-wheel ascent and post-ascent. The greatest effort was generated by the shoulder flexors and internal rotators as well as the elbow flexors. A significant difference (p < 0.0167) between the curb heights was found for most outcome measures studied: movement excursion, net joint moments and muscular utilization ratio (MUR) of the main muscles increased with the higher curb heights, mainly around the shoulder joint. These results provide insight that aside from adhering to a highly structured training method for wheelchair curb ascent, rehabilitation professionals need to propose task-specific strength training programs based on the demands documented in this study and continue to advocate for physically accessible environments.

The impact of transfer setup on the performance of independent wheelchair transfers

OBJECTIVE

The aim of this study was to determine how selected environmental factors affect transfers and to compare our results to the Americans with Disabilities Act Accessibility Guidelines (ADAAG).

BACKGROUND

Few data are available to support standards development related to transfers in the built environment.

METHOD

Participants were 120 wheeled mobility device (WMD) users who transferred to and from a modular transfer station that consisted of a height-adjustable platform with a lateral grab bar, optional obstacle to the transfer, and an optional height-adjustable front grab bar. Maximum and minimum vertical heights of the transfer surface, maximum gap distance between the WMD and transfer surface, grab bar use, and WMD space needs were recorded.

RESULTS

The 95th percentile lowest and highest heights attained were similar to the median WMD seat-to-floor height (56 cm).We found that 42% (47/113) could not perform a transfer with the obstacle present. Participants transferred higher when the front grab bar was added to the setup (p = .005) and higher and lower with the front grab bar than without it when the obstacle was present in the setup (p = .003 and p = .005, respectively). We found that 95% of participants performed a transfer across an 8.9-cm gap. ADAAG recommendations fall short for the height and clear-space needs of the 50th-percentile WMD users.

CONCLUSION

Revisions concerning transfer heights, gaps, clear spaces, and grab bar heights are necessary to make transfers more accessible to WMD users.

APPLICATION

The data will be used to revise the guidelines related to transfers and to enable designers and engineers to create an environment that is more accessible.

Impact of Functional Electrical Stimulation of Lower Limbs during Sitting Pivot Transfer Motion for Paraplegic People

Individuals with Spinal Cord Injury (SCI), perform Sitting Pivot Transfer (SPT) motion around fifteen times a day using upper extremities. It can lead to upper limbs pain and often shoulder complications. In this paper, we investigate the influence of Functional Electrical Stimulation (FES) on SPT motion of a paraplegic person. First, we proposed to develop a dynamic optimization method in order to predict SPT motion of an able-bodied subject. This approach has been validated by comparing the computed SPT trajectories with the ones measured during the experiment with an able-bodied subject. Then, we used the optimization tool to analyze the influence of FES on the SPT maneuver of paraplegic persons. Our results suggest that FES can decrease arm participation during the transfer motion of a paraplegic person.

Effects of sensorimotor trunk impairments on trunk and upper limb joint kinematics and kinetics during sitting pivot transfers in individuals with a spinal cord injury

BACKGROUND

Depending on the level and severity of the sensorimotor impairment in individuals with a spinal cord injury, the subsequent reduced seated postural stability and strength generating-capacity at the upper limbs could affect performance during sitting pivot transfer. This study aimed to determine the effects of sensorimotor impairments on head, trunk and upper limb movement and efforts during sitting pivot transfers.

METHODS

Twenty-six individuals with a spinal cord injury participated and were stratified in two subgroups: with (N=15) and without voluntary motor control (N=11) of their lower back and abdominal muscles. Kinematics and kinetics of sitting pivot transfer were collected using a transfer assessment system. Mean joint angles and movement amplitudes and peak and average joint moments were compared between subgroups using independent Student t-tests (P<0.05) for the weight-bearing sitting pivot transfer phases.

FINDINGS

The subgroup without voluntary control of their lower back and abdominal muscles had significantly greater forward trunk flexion compared to the other subgroup resulting in higher wrist extension and elbow flexion at both upper limbs. No significant joint moment difference was found between the subgroups.

INTERPRETATION

Individuals with spinal cord injury who have no voluntary motor control of their abdominal and lower back muscles increase forward trunk flexion during sitting pivot transfers 1) to increase stiffness of their spine that may optimize the strength-generating ability of their thoracohumeral muscles and 2) to lower their center of mass that may facilitate lift-off and enhance the overall stability during sitting pivot transfers.

The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion

Background

The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns.

Methods

Twelve inexperienced subjects (22.3±1.6 yr) participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s.

Results

The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p < 0.01). A single loop pattern (SLOP) was adopted by most of the subjects.

Conclusions

The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration.

A musculoskeletal modeling approach for estimating anterior cruciate ligament strains and knee anterior-posterior shear forces in stop-jumps performed by young recreational female athletes

The central goal of this study was to contribute to the advancements being made in determining the underlying causes of anterior cruciate ligament (ACL) injuries. ACL injuries are frequently incurred by recreational and professional young female athletes during non-contact impact activities in sports like volleyball and basketball. This musculoskeletal-neuromuscular study investigated stop-jumps and factors related to ACL injury like knee valgus and internal-external moment loads, knee anterior-posterior (AP) shear forces, ACL strains and internal forces. Motion capture data was obtained from the landing phase of stop-jumps performed by eleven young recreational female athletes and electromyography (EMG) data collected from quadriceps, hamstring and gastrocnimius muscles which were then compared to numerically estimated activations. Numerical simulation tools used were Inverse Kinematics, Computed Muscle Control and Forward Dynamics and the knee modeled as a six degree of freedom joint. Results showed averaged peak strains of 12.2 ± 4.1% in the right and 11.9 ± 3.0% in the left ACL. Averaged peak knee AP shear forces were 482.3 ± 65.7 N for the right and 430.0 ± 52.4 N for the left knees, approximately equal to 0.7-0.8 times body weight across both knees. A lack of symmetry was observed between the knees for valgus angles (p < 0.04), valgus moments (p < 0.001) and muscle activations (p < 0.001), all of which can be detrimental to ACL stability during impact activities. Comparisons between recorded EMG data and estimated muscle activations show the relation between electrical signal and muscle depolarization. In summary, this study outlines a musculoskeletal simulation approach that provides numerical estimations for a number of variables associated with ACL injuries in female athletes performing stop-jumps.

Development of custom measurement system for biomechanical evaluation of independent wheelchair transfers

This study describes a new custom measurement system designed to investigate the biomechanics of sitting-pivot wheelchair transfers and assesses the reliability of selected biomechanical variables. Variables assessed include horizontal and vertical reaction forces underneath both hands and three-dimensional trunk, shoulder, and elbow range of motion. We examined the reliability of these measures between 5 consecutive transfer trials for 5 subjects with spinal cord injury and 12 nondisabled subjects while they performed a self-selected sitting pivot transfer from a wheelchair to a level bench. A majority of the biomechanical variables demonstrated moderate to excellent reliability (r > 0.6). The transfer measurement system recorded reliable and valid biomechanical data for future studies of sitting-pivot wheelchair transfers.We recommend a minimum of five transfer trials to obtain a reliable measure of transfer technique for future studies.

Development of an automated method to detect sitting pivot transfer phases using biomechanical variables: toward a standardized method

Background

Sitting pivot transfer (SPT) is one of the most important, but at the same time strenuous at the upper extremity, functional task for spinal cord injured individuals. In order to better teach this task to those individuals and to improve performance, a better biomechanical understanding during the different SPT phases is a prerequisite. However, no consensus has yet been reached on how to depict the different phases of the SPT. The definition of the phases of the SPT, along with the events characterizing these phases, will facilitate the interpretation of biomechanical outcome measures related to the performance of SPTs as well as strengthen the evidence generated across studies.

Methods

Thirty-five individuals with a spinal cord injury performed two SPTs between seats of similar height using their usual SPT technique. Kinematics and kinetics were recorded using an instrumented transfer assessment system. Based on kinetic and kinematic measurements, a relative threshold-based algorithm was developed to identify four distinct phases: pre-lift, upper arm loading, lift-pivot and post-lift phases. To determine the stability of the algorithm between the two SPTs, Student t-tests for dependent samples were performed on the absolute duration of each phase.

Results

The mean total duration of the SPT was 2.00 ± 0.49 s. The mean duration of the pre-lift, upper arm loading, lift-pivot and post-lift phases were 0.74 ± 0.29 s, 0.28 ± 0.13 s, 0.72 ± 0.24 s, 0.27 ± 0.14 s whereas their relative contributions represented approximately 35%, 15%, 35% and 15% of the overall SPT cycle, respectively. No significant differences were found between the trials (p = 0.480-0.891).

Conclusion

The relative threshold-based algorithm used to automatically detect the four distinct phases of the SPT, is rapid, accurate and repeatable. A quantitative and thorough description of the precise phases of the SPT is prerequisite to better interpret biomechanical findings and measure task performance. The algorithm could also become clinically useful to refine the assessment and training of SPTs.

Movement strategies during car transfers in individuals with tetraplegia: a preliminary study

STUDY DESIGN

Three-dimensional kinematic analysis of car transfer (CT) movement in four adult males with C6 tetraplegia.

OBJECTIVES

The aim of the present study was to assess the normal transfer technique movement from a wheelchair to a car (that is, CT) in subjects with tetraplegia. A better understanding of CT movement is invaluable knowledge for spinal cord injury rehabilitation. This type of knowledge will improve rehabilitation programs so that patients with tetraplegia will have greater societal participation.

SETTING

School of Comprehensive Rehabilitation, Osaka Prefecture University, Osaka, Japan.

METHODS

Four adult males with C6 tetraplegia, an impairment grade of A according to the American Spinal Injury Association guidelines, took part in the study. The subjects used their own wheelchair and car in our assessments of their CT movement technique. Movements were assessed using a three-dimensional video analysis system with six digital video cameras. CT data, which included lateral displacement of the head and buttocks, and angular displacement of neck flexion and trunk forward inclination, were collected and correlation coefficients were calculated.

RESULTS

All four subjects demonstrated negative correlations in lateral displacements greater than 0.70. As for correlation coefficients of angular displacement, two subjects demonstrated negative correlations (r = -0.98 and r = -0.77) and one subject demonstrated a positive correlation (r = 0.75). The neck flexion and trunk forward inclination strategy was different among the four subjects.

CONCLUSIONS

Each subject with C6 tetraplegia demonstrated different strategies during CT movement.

An expert review of the scientific literature on independent wheelchair transfers

PURPOSE

The purpose of this study was to perform a literature review and seek expert opinion on the relevance and strength of the evidence concerning setup and transfer performance.

METHODS

Scientific literature databases were searched until June 2009 using 43 keywords resulting in 339 articles. These were internally reviewed and narrowed to 41 articles which were formally assessed by 13 external experts. Articles that 80% or more of the reviewers scored as moderately or highly relevant were included in the final results.

RESULTS

Nineteen articles met the relevancy criteria. The aspects of setup that experts felt were addressed to some degree included vertical transfer distance, transferring across a gap and position of the mobility device relative to target destination. None of the 19 articles were scored as having strong to very strong resulting evidence.

CONCLUSIONS

There is a consensus among studies that transferring to a higher surface implies greater exertion of the upper limb. However, there is no evidence concerning how high or low, how close, and how much space is needed next to the target surface so it can be accessible by a majority of wheelchair users.

Avaliação cinemática da transferência de paraplégicos da cadeira de rodas

OBJETIVO: Avaliar a estratégia das transferências de paraplégicos da cadeira de rodas. MÉTODOS: Participaram do estudo doze sujeitos lesados medulares (T2 a T12), aptos a realizar independentemente a transferência da cadeira de rodas para um tablado com um metro quadrado (m²) de área por meio metro de altura. As imagens de marcadores reflexivos nos pontos anatômicos foram capturadas por seis câmeras de infravermelho ProReflex e processadas através de um software específico (QTrac). Parâmetros cinemáticos do tronco, cabeça, ombros e cotovelos foram avaliados. RESULTADOS: Os dados analisados comparam o lado preferencial do sujeito para realizar a transferência com o lado não preferencial, de acordo com as funções desempenhadas de cada segmento corporal. O deslocamento angular da cabeça no plano sagital (y-z) e ombros no plano transversal (x-y) mostraram significâncias estatísticas (p<0,05). Conclusão: Os dados obtidos neste estudo mostraram que há diferenças na estratégia da transferência dos paraplégicos do lado preferencial em comparação com o lado não preferencial. Nível de Evidência II, Desenvolvimento de critérios diagnósticos em pacientes consecutivos (com padrão de evidência "ouro" aplicado).

Manual wheeled mobility--current and future developments from the human engineering research laboratories

Medical rehabilitation and assistive technology are immersed in a world transitioning to a basis in evidence-based practice. Fortunately, there is a growing body of knowledge related to manual wheelchair mobility to form a basis for clinical decision making. The results from research studies are useful for designing better wheelchairs, fitting and training people appropriately, contributing to evidence-based-medicine and guiding future research. This review describes some of the work related to manual wheelchairs that has and is being conducted within the University of Pittsburgh and the Human Engineering Research Laboratories of the United States Department of Veterans Affairs, and its application.