Paralyzed Veterans of America Consortium for Spinal Cord Medicine. Preservation of upper limb function following spinal cord injury: a clinical practice guideline for health-care professionals

The effect of a cognitive dual-task on the control of wheelchair propulsion

Movement analyses of wheelchair users are rarely integrated into clinical operations, although these are recommended to prevent pain and injury in the upper extremity. In addition, previous movement analyses in the laboratory do not include the possible influences of distractions that occur in everyday wheelchair use. We therefore transferred the dual-task method known from the motion analysis of walkers to the analysis of the propulsion behavior of wheelchair users and examined whether the changes resulting from the additional cognitive task also show up here. The 52 participants consisted of 38 manual wheelchair users (age = 43.8 ± 14.2 years; sex = 11/27 f/m) and 14 novices (age = 39.2 ±  15.4 years; sex = 8/6 f/m). The participants propelled their wheelchairs on a test stand and movements of hand and wheel were recorded with a marker-based 3D motion-capturing system. The measurements were performed at preferred speed under single- and dual-task conditions. The Paced Auditory Serial Addition Test (PASAT) was used for the additional cognitive task. The participants propelled with a significantly higher frequency (p = 0.001), had a shorter cycle- (p = 0.001) and recovery time (p = 0.001) and propelled with a lower push angle (p = 0.045) under dual-task conditions. The distance between the hand and the pushrim was shorter (p = 0.008) and the distance between the hand and the axis was significantly longer (p = 0.004). The differences occurred predominantly in the group of manual wheelchair users. Significant differences in propulsion behavior were also found between the two groups under both single-task and dual-task conditions. The results indicate that dual-task conditions during wheelchair propulsion have an influence on spatiotemporal parameters similar to walking. Future movement analyses of wheelchair users should therefore consider the additional measurement under dual-task conditions in order to obtain more realistic results.

Manual wheelchair training approaches and intended training outcomes for adults who are new to wheelchair use: A scoping review

INTRODUCTION

Wheelchair training is pivotal for safety, independence, and occupational engagement in the community, yet adults coming into wheelchair use often receive insufficient or untailored training. This research aimed to understand the range and type of manual wheelchair training approaches that exist for adults commencing wheelchair use.

METHOD

A systematic scoping review involved searching eight electronic databases and grey literature up to September 2023. Papers relating to manual wheelchair training for adults and their caregivers were included for data extraction. Eighty-seven articles were included in this review. The International Classification of Functioning (ICF) was used to organise and analyse data related to intended training outcomes.

CONSUMER AND COMMUNITY INVOLVEMENT

Consumer consultation was not included in this review; however, the outcomes suggest that involving consumers in future wheelchair training research is critical to assure community participation outcomes.

RESULTS

Data were extracted from 87 papers. Manual wheelchair training was delivered across diverse contexts encompassing varied support structures, trainer backgrounds, and technology and was commonly directed towards wheelchair users with spinal cord injury. Intended training outcomes most frequently mapped to the activity and participation component of the ICF (n = 39), followed by personal factors (n = 27), body structures and functions (n = 18), and environmental factors (n = 3), with limited focus on longer term occupational engagement outcomes.

CONCLUSION

Most existing manual wheelchair training focussed on the acquisition of individual wheelchair skill and may not facilitate generalised and long-term occupational participation outcomes. Further exploration into the contexts that support occupational engagement, particularly for older adults with progressive conditions, is required to support service provision.

PLAIN LANGUAGE SUMMARY

We looked at what manual wheelchair training approaches exist for adults who need to use a manual wheelchair and what training helps people to do/achieve. We did a scoping review that looked at literature about manual wheelchair training programs for adult wheelchair users. We found 87 research papers and training programs that we included in our review. We recorded and analysed information from all the papers about the wheelchair training programs and outcomes for people who do these programs. We found that manual wheelchair training can be done in structured or ad hoc ways, can have different amounts of training, can be provided face-to-face or online, and can be given by different allied health professionals and other wheelchair users. Most training programs had short-term outcomes like learning manual wheelchair skills, being able to use the wheelchair properly, and feeling confident about using a wheelchair. Some had longer term outcomes about being able to use the manual wheelchair in everyday activities. Most people who did the training programs that we looked at in this review were manual wheelchair users with spinal cord injury. Because not many wheelchair programs have been tried with people who do not have a spinal cord injury, it is hard for occupational therapists to make recommendations about training for other people who use a manual wheelchair. Manual wheelchair training that is done in the community and made to meet the needs of individuals may help people with using their wheelchair for their everyday activities and participate in their community.

A user-inspired mobility experience of the future: a qualitative investigation

Wheelchair users (WCUs) face additional challenges than non-WCU to multi-tasking (i.e. open doors, cook, use a cell-phone) while navigating their environments. While assistive devices have attempted to provide WCUs with mobility solutions that enable multi-tasking capabilities, current devices have been developed without the input of end-users and have proven to be non-usable. More balanced approaches that integrate the end-users' voices may improve current assistive technology usability trends. This study sought to empathically understand the lived experience of WCUs, their needs towards a mobility device, and their perceptions towards hands-free mobility. Full-time WCUs and care providers participated in semi-structured interviews examining wheelchair use and perceptions towards current and future mobility devices. Thematic analysis was used to analyze interview data. 9 WCUs (aged 32.1 ± 7.0 years; wheelchair experience 17.9 ± 11.6 years) and five care providers (years caring for WCU 3.75 ± 0.96 years) participated in the study. The most common disability type was spinal cord injury (WCUs: n = 3; care providers: n = 3). Qualitative analysis revealed four key themes: (1) Current wheelchair usage, (2) WCU and care provider perspectives, (3) Future wheelchair, and (4) Hands-free wheelchair. Accordingly, participants desire bespoke, light-weight mobility devices that can through tight spaces, access uneven terrain, and free the hands during navigation. This study provides meaningful insight into the needs of WCUs and care providers that assistive technology innovators can use to develop more usable assistive technologies. Amongst study participants, the concept of a hands-free mobility device appears to be usable and desirable.

Wheelchair satisfaction and recommended improvements of manual wheelchairs in the UK

PURPOSE OF THE ARTICLE

The aim of this study was to determine user satisfaction with manual wheelchairs in the United Kingdom and to determine areas that could be improved to help drive future design and development.

MATERIALS AND METHODS

Manual wheelchair users, aged 18-65 years old living in the United Kingdom, were invited, to complete an online cross-sectional questionnaire. The link to the questionnaire was distributed using a range of methods to charities, organisations and wheelchair user groups via invitation by email and social media. Responses were gathered from 122 respondents and analysed using descriptive statistics, cross-tabulation and content analysis.

RESULTS

Respondents felt comfort (39.3%), weight (35.4%), manoeuvrability (34.3%) and durability (30.7%) were the most important features of a wheelchair. Seventy percent of respondents that were "not at all satisfied" with their current wheelchair were fitted by the National Health Service (NHS, X2 = 42.39, p < 0.001). Ninety percent of respondents who were "not at all satisfied" with their current wheelchair experienced issues with comfort (X2 = 17.82, p = 0.001). Sixty percent who were "not satisfied at all" with their wheelchair had not chosen their wheelchair (X2 = 25.15, p < 0.001).

CONCLUSION

Wheelchair satisfaction was largely determined by comfort, location of the users' wheelchair fitting (for example the NHS) and users choosing their own wheelchair. Future wheelchair designs should utilise a user centred and inclusive design approach to cater for a wider range of individual needs and requirements.

Development of the RightWheel manual wheelchair wheel rolling resistance clinical decision support system through iterative clinician interviews

Introduction

Manual wheelchair users (MWU) frequently experience upper limb (UL) injury and pain. Clinical practice guidelines (CPG) provide guidance on how to reduce risk of UL injury and pain but the recommendations provide only general advice such as to minimizing repetitive strain by reducing rolling resistance (RR). RR is due to energy loss between wheels and ground during wheelchair propulsion and is a major contributor of repetitive strain for MWUs. Motivated by the recommendation to reduce RR, we developed a clinical decision support system (CDSS) to provide client-specific RR predictions across several wheelchair setups to allow clinicians and users to make informed decisions.

Methods

An iterative user-centered design process (mixed methods) recruited ATP certified occupational or physical therapists to suggest modifications, assess usability and usefulness, identify client use cases, and provide rear wheel and caster selection criteria.

Results

Six clinicians participated and suggested over 100 modifications. Usability (SUS = 83.8; modified QUIS = 7.5) and perceived usefulness (TAQ = 4.7) were acceptable. Client use cases and rear wheel and caster selection criteria were identified. All clinicians thought it would be a useful tool.

Conclusions

RightWheel online CDSS provides user-customized RR estimates for equipment options in an easy-to-understand format, and was deemed ready for pilot launch.

Non-invasive Transcutaneous Spinal Cord Stimulation Programming Recommendations for the Treatment of Upper Extremity Impairment in Tetraplegia

OBJECTIVES

This study analyzes the stimulation parameters implemented during two successful trials that used non-invasive transcutaneous spinal cord stimulation (tSCS) to effectively improve upper extremity function after chronic spinal cord injury (SCI). It proposes a framework to guide stimulation programming decisions for the successful translation of these techniques into the clinic.

MATERIALS AND METHODS

Programming data from 60 participants who completed the Up-LIFT trial and from 17 participants who subsequently completed the LIFT Home trial were analyzed. All observations of stimulation amplitudes, frequencies, waveforms, and electrode configurations were examined. The incidence of adverse events and relatedness to stimulation parameters is reported. A comparison of parameter usage across the American Spinal Injury Association Impairment Scale (AIS) subgroups was conducted to evaluate stimulation strategies across participants with varying degrees of sensorimotor preservation.

RESULTS

Active (cathodal) electrodes were typically placed between the C3/C4 and C6/C7 spinous processes. Most sessions featured return (anodal) electrodes positioned bilaterally over the anterior superior iliac spine, although clavicular placement was frequently used by 12 participants. Stimulation was delivered with a 10-kHz carrier frequency and typically a 30-Hz burst frequency. Biphasic waveforms were used in 83% of sessions. Average stimulation amplitudes were higher for biphasic waveforms. The AIS B subgroup required significantly higher amplitudes than did the AIS C and D subgroups. Device-related adverse events were infrequent, and not correlated with specific waveforms or amplitudes. Within the home setting, participants maintained their current amplitudes within 1% of the preset values. The suggested stimulation programming framework dictates the following hierarchical order of parameter adjustments: current amplitude, waveform type, active/return electrode positioning, and burst frequency, guided by clinical observations as required.

CONCLUSIONS

This analysis summarizes effective stimulation parameters from the trials and provides a decision-making framework for clinical implementation of tSCS for upper extremity functional restoration after SCI. The parameters are aligned with existing literature and proved safe and well tolerated by participants.

Upper limb muscle strength and wheelchair-related abilities following an exoskeleton-assisted walking programme in individuals with chronic spinal cord injury: An exploratory study

OBJECTIVES

To measure the potential effects of an overground exoskeleton-assisted walking programme on upper limb strength and mass, as well as on wheelchair propulsion performances and abilities in individuals with chronic spinal cord injury.

DESIGN

Prospective, single-group, pre-post intervention study.

PARTICIPANTS

Ten individuals with chronic (≥ 18 months) spinal cord injury who use a wheelchair as their primary mode of locomotion and who had little-to-no motor function in the lower limbs.

METHODS

Individuals completed a progressive 16-week exoskeleton-assisted walking programme (34 × 1-h sessions, 1-3 sessions/week). Upper limb muscle strength was measured with dynamometers (isokinetic, Jamar). Upper limb lean mass (dual-energy X-ray absorptiometry) was used to calculate relative strength. Field tests (20-m wheelchair propulsion, and slalom test) and the Wheelchair Skills Test Questionnaire determined performances and abilities. Wilcoxon signed-rank tests were used with the following criteria: p < 0.1, effect size ≥ 0.5, and relative variation > 5%.

RESULTS

Only natural velocity during the 20-m wheelchair propulsion test (i.e., fundamental wheelchair ability) changed following the intervention (p = 0.01, effect size = 0.82, relative variation = +14.5%).

CONCLUSION

Overall, upper limb muscle function did not significantly and meaningfully change following the exoskeleton-assisted walking programme in this population. Additional research is needed to verify how changes in training volume would affect strength and advanced wheelchair-related abilities and performance, as well as the response in individuals who are deconditioned or novices to wheelchair use (e.g., subacute spinal cord injury).

Recommendations for long-term follow-up care of secondary health conditions in spinal cord injury/disorder: a systematic review

Objectives

The purpose of this systematic review is to provide an overview of published follow-up care programs of primary and secondary health conditions (SHCs) in spinal cord injury/disorder (SCI/D) and spina bifida and describe recommendations on content, frequency, setting of follow-up care programs for persons with SCI/D and spina bifida.

Methods

According to the sequence of procedures of the AWMF (Association of the Scientific Medical Societies in Germany) a systematic literature search was performed (in PubMed, Cochrane Library and nine additional databases for guidelines) between 5 September 2019 and 22 September 2019. Publications (Jan. 2008-Dec. 2018) and guidelines (up to 2018) published in English or German and describing an evidence-based follow-up care program for persons with SCI/D or spina bifida were included.

Results

The systematic literature search found 1973 publications in PubMed and Cochrane Library, resulting in 19 papers for SCI/D and 6 for Spina bifida. Additionally, we included 34 guidelines developed by reputable committees or medical associations. All eligible guidelines, and publications, were rated and classified according to the guidance of AWMF. Of the retrieved publications, and guidelines, level of evidence of follow-up care programs was mostly based on informal procedures and expert opinion or formally consent based expert opinion. None of the guidelines, or publications described an evidence based comprehensive clinical practice guideline (CPG) for follow-up care for people with SCI/D or spina bifida.

Conclusion

Based on the comprehensive and extensive literature research conducted, regular (annual) follow-up care appointments at specialized SCI clinics are recommended. There is a notable absence of a comprehensive CPG covering all relevant health conditions for long-term follow-up in SCI/D or spina bifida. In order to provide persons with SCI/D with up-to-date and best possible medical and rehabilitative care, a CPG for follow-up care is urgently needed. In response to this gap, the German-speaking Medical Society of Paraplegia (DMGP) has commissioned its members to establish a guideline for follow-up care for individuals with SCI/D. The current review serves as an evidence-based framework for the development of this guideline.

Handrim Reaction Force and Moment Assessment Using a Minimal IMU Configuration and Non-Linear Modeling Approach during Manual Wheelchair Propulsion

Manual wheelchair propulsion represents a repetitive and constraining task, which leads mainly to the development of joint injury in spinal cord-injured people. One of the main reasons is the load sustained by the shoulder joint during the propulsion cycle. Moreover, the load at the shoulder joint is highly correlated with the force and moment acting at the handrim level. The main objective of this study is related to the estimation of handrim reactions forces and moments during wheelchair propulsion using only a single inertial measurement unit per hand. Two approaches are proposed here: Firstly, a method of identification of a non-linear transfer function based on the Hammerstein-Wiener (HW) modeling approach was used. The latter represents a typical multi-input single output in a system engineering modeling approach. Secondly, a specific variant of recurrent neural network called BiLSTM is proposed to predict the time-series data of force and moments at the handrim level. Eleven subjects participated in this study in a linear propulsion protocol, while the forces and moments were measured by a dynamic platform. The two input signals were the linear acceleration as well the angular velocity of the wrist joint. The horizontal, vertical and sagittal moments were estimated by the two approaches. The mean average error (MAE) shows a value of 6.10 N and 4.30 N for the horizontal force for BiLSTM and HW, respectively. The results for the vertical direction show a MAE of 5.91 N and 7.59 N for BiLSTM and HW, respectively. Finally, the MAE for the sagittal moment varies from 0.96 Nm (BiLSTM) to 1.09 Nm for the HW model. The approaches seem similar with respect to the MAE and can be considered accurate knowing that the order of magnitude of the uncertainties of the dynamic platform was reported to be 2.2 N for the horizontal and vertical forces and 2.24 Nm for the sagittal moments. However, it should be noted that HW necessitates the knowledge of the average force and patterns of each subject, whereas the BiLSTM method do not involve the average patterns, which shows its superiority for time-series data prediction. The results provided in this study show the possibility of measuring dynamic forces acting at the handrim level during wheelchair manual propulsion in ecological environments.

Handrim kinetics and quantitative ultrasound parameters for assessment of subacromial impingement in wheelchair users with pediatric-onset spinal cord injury

BACKGROUND

Most manual wheelchair users with pediatric-onset spinal cord injury (SCI) will experience shoulder pain or pathology at some point in their life. However, guidelines for preservation of the upper limb in children with SCI are limited.

RESEARCH QUESTION

What are the relationships between manual wheelchair handrim kinetics and quantitative ultrasound parameters related to subacromial impingement in individuals with pediatric-onset SCI?

METHODS

Subacromial impingement risk factors including supraspinatus tendon thickness (SST), acromiohumeral distance (AHD), and occupation ratio (OR; SST/AHD) were measured with ultrasound in 11 manual wheelchair users with pediatric-onset SCI. Handrim kinetics were acquired during the stroke cycle, including peak resultant force (FR), peak rate of rise of resultant force (ROR) and fractional effective force (FEF). Variability of handrim kinetics was computed using the coefficient of variation and linear regression was performed to assess correlations between handrim metrics and quantitative ultrasound parameters.

RESULTS

Peak resultant force significantly increased 1.4 % and variability of FEF significantly decreased 8.0 % for every 0.1 cm increase in AHD. FEF decreased 3.5 % for every 0.1 cm increase in SST. Variability of peak resultant force significantly increased 3.6 % and variability of peak ROR of resultant force significantly increased 7.3 % for every 0.1 cm increase in SST. FEF variability significantly decreased 11.6 % for every 0.1 cm increase in SST. Peak ROR significantly decreased 1.54 % with every 10 % increase in OR. FEF variability significantly decreased 1.5 % with every 10 % increase in OR.

SIGNIFICANCE

This is the first study to investigate relationships among handrim kinetics and shoulder structure in manual wheelchair users with pediatric-onset SCI. Associations were identified between subacromial impingement risk factors and magnitude and variability of wheelchair handrim kinetics. These results indicate the critical need to further explore the relationships among wheelchair handrim kinetics, shoulder joint dynamics, and shoulder pathology in manual wheelchair users with pediatric-onset SCI.

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

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

Feasibility and Validity of Wearable Sensors for Monitoring Temporal Parameters in Manual Wheelchair Propulsion

Upper extremity pain and injury are among the most common musculoskeletal complications manual wheelchair users face. Assessing the temporal parameters of manual wheelchair propulsion, such as propulsion duration, cadence, push duration, and recovery duration, is essential for providing a deep insight into the mobility, level of activity, energy expenditure, and cumulative exposure to repetitive tasks and thus providing personalized feedback. The purpose of this paper is to investigate the use of inertial measurement units (IMUs) to estimate these temporal parameters by identifying the start and end time of hand contact with the push-rim during each propulsion cycle. We presented a model based on data collected from 23 participants (14 males and 9 females, including 9 experienced manual wheelchair users) to guarantee the reliability and generalizability of our method. The obtained outcomes from our IMU-based model were then compared against an instrumented wheelchair (SMARTWheel) as a reference criterion. The results illustrated that our model was able to accurately detect hand contact and hand release and predict temporal parameters, including the push duration and recovery duration in manual wheelchair users, with the mean error ± standard deviation of 10 ± 60 milliseconds and -20 ± 80 milliseconds, respectively. The findings of this study demonstrate the potential of hand-mounted IMUs as a reliable and objective tool for analyzing temporal parameters in manual wheelchair propulsion. IMUs offer significant strides towards inclusivity and accessibility due to their portability and user-friendliness and can democratize health monitoring of manual wheelchair users by making it accessible to a broader range of users compared to traditional technologies.

Transcriptomics reveals transient and dynamic muscle fibrosis and atrophy differences following spinal cord injury in rats

BACKGROUND

The rate and magnitude of skeletal muscle wasting after severe spinal cord injury (SCI) exceeds most other disuse conditions. Assessing the time course of molecular changes can provide insight into the progression of muscle wasting post-SCI. The goals of this study were (1) to identify potential targets that may prevent the pathologic features of SCI in soleus muscles and (2) to establish therapeutic windows for treating these pathologic changes.

METHODS

Four-month-old Sprague-Dawley male rats received T9 laminectomy (SHAM surgery) or severe contusion SCI. Hindlimb locomotor function was assessed weekly, with soleus muscles obtained 1 week, 2 weeks, 1 month and 3 months post-surgery (n = 6-7 per group per timepoint). RNA was extracted from muscles for bulk RNA-sequencing analysis (n = 3-5 per group per timepoint). Differentially expressed genes (DEGs) were evaluated between age-matched SHAM and SCI animals. Myofiber size, muscle fibre type and fibrosis were assessed on contralateral muscles.

RESULTS

SCI produced immediate and persistent hindlimb paralysis, with Basso-Beattie-Bresnahan locomotor scores remaining below 7 throughout the study, contributing to a progressive 25-50% lower soleus mass and myofiber atrophy versus SHAM (P < 0.05 at all timepoints). Transcriptional comparisons of SCI versus SHAM resulted in 184 DEGs (1 week), 436 DEGs (2 weeks), 133 DEGs (1 month) and 1200 DEGs (3 months). Upregulated atrophy-related genes included those associated with cell senescence, nuclear factor kappa B, ubiquitin proteasome and unfolded protein response pathways, along with upregulated genes that negatively influence muscle growth through the transforming growth factor beta pathway and inhibition of insulin-like growth factor-I/Akt/mechanistic target of rapamycin and p38/mitogen-activated protein kinase signalling. Genes associated with extracellular matrix (ECM), including collagens, collagen crosslinkers, proteoglycans and those regulating ECM integrity, were enriched within upregulated DEGs at 1 week but subsequently downregulated at 2 weeks and 3 months and were accompanied by >50% higher ECM areas and hydroxyproline levels in SCI muscles (P < 0.05). Myofiber remodelling genes were enriched in upregulated DEGs at 2 weeks and 1 month and were downregulated at 3 months. Genes that regulate neuromuscular junction remodelling were evident in muscles post-SCI, along with slow-to-fast fibre-type shifts: 1 week and 2 weeks SCI muscles were composed of 90% myosin heavy chain (MHC) type I fibres, which decreased to only 16% at 3 months and were accompanied by 50% fibres containing MHC IIX (P < 0.05). Metabolism genes were enriched in upregulated DEGs at 1 month and were further enriched at 3 months.

CONCLUSIONS

Our results substantiate many known pathologic features of SCI-induced wasting in rat skeletal muscle and identify a progressive and dynamic transcriptional landscape within the post-SCI soleus. Future studies are warranted to consider these therapeutic treatment windows when countering SCI muscle pathology.

Finger Roll-Up Prevention Mechanism for Control of Flexion Rate in a Cable-Driven Grasping Exoskeleton

This paper presents the design and implementation of an Anti-Finger Roll-Up (AFRU) mechanism for a cable-driven grasp assistance exoskeleton. Finger rollup describes the premature flexion of the distal and proximal interphalangeal joints relative to the metacarpophalangeal joint as a result of a cable pulling directly on the fingertip. This leads to unstable pinching grasps or grasps that place the target object outside of the grasp envelope.This device provides a solution to finger roll-up by emulating an increase in joint stiffness in the distal interphalangeal and proximal interphalangeal joints. A passive spring steel leaflet is attached to the anterior side of the exoskeleton to oppose flexion. To evaluate this mechanism, a surrogate hand with elastic joints was fabricated and used as an experimental test bed of the anti-finger roll-up capabilities of the exoskeleton, while emulating biomechanical properties of a human hand. To assist clinicians who want to emulate this mechanism, a dynamic model of the cable-driven exoskeleton, finger, surrogate joints, and spring steel leaflet has been developed to assist in adapting this device to the various pathologies.

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

CONTEXT

Strong upper limb musculature is essential for persons with spinal cord injury (SCI) to operate a manual wheelchair and live independently. Targeted upper limb vibration may be a viable exercise modality to build muscle efficiently while eliminating some of the barriers associated with exercise for persons with SCI.

OBJECTIVE

The purpose of this study was to assess preliminary feasibility of completing a single exercise session of upper limb vibration and compare the acute physiological effects to a single session of standard dumbbell resistance exercise.

METHODS

Individuals with SCI performed seven upper limb exercises (1) isometrically using a vibrating dumbbell at 30 Hz for 60 s (n = 22) and (2) using a standard isotonic resistance protocol (n = 15).

RESULTS

Nineteen (86.4%) of 22 participants were able to perform all vibration exercises at 30 Hz but hold time success rates varied from 33% (side flies and front raises) to 95% (internal rotation). No significant differences were found between vibration exercise and standard resistance protocol for blood lactate, power output, and heart rate (P > 0.05). Perceptions of the training were positive, with most participants (>70%) expressing interest to train with vibration in the future.

CONCLUSIONS

Vibration training was not feasible for all participants, suggesting an individualized approach to starting weight and progression may be necessary. Similar acute physiological changes were seen between vibration exercise and standard resistance protocol, suggesting they could have similar benefits. Additional research is needed to determine if vibration exercise is feasible and beneficial to incorporate into a long-term training program.

Relationship between rolling resistance, preferred speed, and manual wheelchair propulsion mechanics in non-disabled adults

PURPOSE

To characterize the relationship among rolling resistance (RR), preferred speed, and propulsion mechanics.

METHODS

N = 11 non-disabled individuals (mean (SD)); Age 24 years (2), BMI 23.8 kg/m2 (4.3) completed a submaximal graded wheelchair exercise test (GXTsubmax, fixed speed, terminated at Rating of Perceived Effort (RPE)=8 (0-10 scale)) and a single-blind, within-subject repeated measures wheelchair propulsion experiment (RME). RR at RPE = 10 (estimated maximum workload, Maxestimated) was estimated from the GXTsubmax RPE-RR relationship. RME consisted of N = 19 1-minute trials (self-selected speed) each followed by 2-minutes rest. The trials included N = 16 unique RR between 25-100% of Maxestimated. Averages of all pushes in N = 16 unique 1-minute trials were computed for average RR (N), speed (m/s), peak force (Fpeak (N)), force rate of rise (Fror (N/s)), push frequency (PF (pushes/min)), and push length (PL (deg)).

RESULTS

Repeated measures correlation assessed relationships among outcome variables (α = 0.05). RR was associated with decreased speed (r=-0.81, p < 0.001), increased Fpeak (r = 0.92), Fror (r = 0.26), and PL (r = 0.32) (all p > 0.001), and unrelated to PF (r = 0.02, p = 0.848). Increased speed was associated with increased Fror (r = 0.23, p = 0.003) and PF (r = 0.27, p < 0.001) and decreased Fpeak (r=-0.66, p < 0.001) and PL (r=-0.25, p < 0.001).

CONCLUSION

Increasing RR increases Fpeak despite reducing self-selected speed. RR and speed were strongly and moderately related to Fpeak, respectively, but weakly related to other propulsion mechanics. These results suggest that reducing user-system RR may confer dual benefits of improved mobility and decreased upper extremity loading. Further testing among wheelchair users is required. Clinical trial registration number: NCT04987177.

Models of care for musculoskeletal shoulder pain in spinal cord injury: A scoping review

CONTEXT

Spinal cord injury (SCI) is a neurological condition that significantly impacts a person's lifestyle, health and well-being. Many individuals with SCI experience secondary musculoskeletal shoulder pain. This scoping review examines the current research on the diagnosis and management of shoulder pain in SCI.

OBJECTIVE

The aim of this Scoping Review was (1) to chart peer-reviewed literature regarding the diagnosis and management of shoulder pain as it relates to SCI and (2) identify gaps in this body of literature to inform future research priorities.

METHODS

Six electronic databases were searched from inception until April 2022. In addition, reviewers scanned the reference lists of identified articles. Articles from peer-reviewed sources that reported diagnostic or management procedures for musculoskeletal shoulder conditions within the SCI population were considered and 1679 articles were identified. Title and abstract screening, full text review, and data extraction were undertaken by two independent reviewers.

RESULTS

Eighty seven articles were included, covering diagnosis or management of shoulder pain in SCI.

CONCLUSION

Whilst the most commonly reported diagnostic procedures and management strategies reflect contemporary practice for shoulder pain, the entire body of literature demonstrates inconsistencies in methodologies. In places, the literature continues to perceive value in procedures inconsistent with best practice. These findings encourage researchers to pursue the development of robust models of care for musculoskeletal shoulder pain in SCI using a collaborative and integrated approach, combining best practice for musculoskeletal shoulder pain alongside clinical expertise in the management of SCI.

Introducing ROHO Hybrid Select Cushion

This article first describes the presentation, impact, prevalence and aetiology of pressure ulceration in wheelchair users. It then explores how to assess the risk of a wheelchair user developing a pressure ulcer and how to reduce this risk with effective skin care, moisture management and surface support, as well as repositioning, nutrition and advice. The article concludes by examining the clinical benefits of wheelchair support surfaces and how to select a cushion from the reactive, dynamic and hybrid types available, with a focus on the ROHO Hybrid Select Cushion (Permobil).

Differences in Glenohumeral Joint Contact Forces Between Recovery Hand Patterns During Wheelchair Propulsion With and Without Shoulder Muscle Weakness: A Simulation Study

The majority of manual wheelchair users (MWCU) develop shoulder pain or injuries, which is often caused by impingement. Because propulsion mechanics are influenced by the recovery hand pattern used, the pattern may affect shoulder loading and susceptibility to injury. Shoulder muscle weakness is also correlated with shoulder pain, but how shoulder loading changes with specific muscle group weakness is unknown. Musculoskeletal modeling and simulation were used to compare glenohumeral joint contact forces (GJCFs) across hand patterns and determine how GJCFs vary when primary shoulder muscle groups are weakened. Experimental data were analyzed to classify individuals into four hand pattern groups. A representative musculoskeletal model was then developed for each group and simulations generated to portray baseline strength and six muscle weakness conditions. Three-dimensional GJCF peaks and impulses were compared across hand patterns and muscle weakness conditions. The semicircular pattern consistently had lower shear (anterior-posterior and superior-inferior) GJCFs compared to other patterns. The double-loop pattern had the highest superior GJCFs, while the single-loop pattern had the highest anterior and posterior GJCFs. These results suggest that using the semicircular pattern may be less susceptible to shoulder injuries such as subacromial impingement. Weakening the internal rotators and external rotators resulted in the greatest increases in shear GJCFs and decreases in compressive GJCF, likely due to decreased force from rotator cuff muscles. These findings suggest that strengthening specific muscle groups, especially the rotator cuff, is critical for decreasing the risk of shoulder overuse injuries.

Functional mobility, employment and safety benefits of seat elevating devices

STATUS OF RESEARCH PROCESS

Study completed.

INVOLVEMENT OF ASSISTIVE TECHNOLOGY USERS

Participants were power wheelchair users.

Steering-by-leaning facilitates intuitive movement control and improved efficiency in manual wheelchairs

BACKGROUND

Manual wheelchair propulsion is widely accepted to be biomechanically inefficient, with a high prevalence of shoulder pain and injuries among users. Directional control during wheelchair movement is a major, yet largely overlooked source of energy loss: changing direction or maintaining straightforward motion on tilted surfaces requires unilateral braking. This study evaluates the efficiency of a novel steering-by-leaning mechanism that guides wheelchair turning through upper body leaning.

METHODS

16 full-time wheelchair users and 15 able-bodied novices each completed 12 circuits of an adapted Illinois Agility Test-course that included tilted, straight, slalom, and 180° turning sections in a prototype wheelchair at a self-selected functional speed. Trials were alternated between conventional and steering-by-leaning modes while propulsion forces were recorded via instrumented wheelchair wheels. Time to completion, travelled distance, positive/negative power, and work done, were all calculated to allow comparison of the control modes using repeated measures analysis of variance.

RESULTS

Substantial average energy reductions of 51% (able-bodied group) and 35% (wheelchair user group) to complete the task were observed when using the steering-by-leaning system. Simultaneously, able-bodied subjects were approximately 23% faster whereby completion times did not differ for wheelchair users. Participants in both groups wheeled some 10% further with the novel system. Differences were most pronounced during turning and on tilted surfaces where the steering-by-leaning system removed the need for braking for directional control.

CONCLUSIONS

Backrest-actuated steering systems on manual wheelchairs can make a meaningful contribution towards reducing shoulder usage while contributing to independent living. Optimisation of propulsion techniques could further improve functional outcomes.

Quantification of the Risk of Musculoskeletal Disorders of the Upper Limb Using Fuzzy Logic: A Study of Manual Wheelchair Propulsion

BACKGROUND

For manual wheelchair users, overuse of the upper limbs can cause upper limb musculoskeletal disorders, which can lead to a loss of autonomy. The main objective of this study was to quantify the risk level of musculoskeletal disorders of different slope propulsions in manual wheelchair users using fuzzy logic.

METHODS

In total, 17 spinal cord injury participants were recruited. Each participant completed six passages on a motorized treadmill, the inclination of which varied between (0° to 4.8°). A motion capture system associated with instrumented wheels of a wheelchair was used. Using a biomechanical model of the upper limb and the fuzzy logic method, an Articular Discomfort Index (ADI) was developed.

RESULTS

We observed an increase in articular discomfort during propulsion on a slope with increasing discomfort at the shoulder, elbow and wrist, due to an increase in kinetics. There was a kinetically significant change in the kinetic global ADI (22 to 25%) and no change in the kinematic. The ADI increased from 14 to 36% during slope propulsion for each joint.

CONCLUSION

The quantification of the level of discomfort helps us to highlight the situations with the most high-risk exposures and to identify the parameters responsible for this discomfort.

The influence of gender on shoulder kinematics and head-hip technique during non-level transfers in full-time wheelchair users

BACKGROUND

Non-level transfers are some of the most demanding tasks for manual wheelchair users. Safely performing these transfer tasks may be needed for maintaining long-term upper limb health. This cross-sectional study aimed to examine the influence of gender on the head-hip technique and lead arm kinematics during multi-height transfers in manual wheelchair users.

METHODS

Motion analysis was used to obtain lead-arm shoulder kinematics (flexion/extension and abduction/adduction) and trunk flexion during level, uphill, and floor-to-table transfers in full-time manual wheelchair users.

FINDINGS

Twelve male (N = 12) and fifteen female (N = 15) manual wheelchair users with a mean age of 23 ± 5 years and no signs of shoulder pain participated in the study. Lead-arm shoulder flexion and abduction increased as vertical displacement requirements increased during the various transfer tasks (p < 0.01). Women displaced greater trunk flexion during level transfers at approaching significant levels (p = 0.07). During uphill transfers, women displayed significantly greater trunk flexion than men (p < 0.05).

INTERPRETATION

Manual wheelchair users use unique kinematic requirements when using the head-hip during level and non-level transfers. Women may be at decreased risk of chronic shoulder pain due to a greater use of the head-hip technique during non-level transfers. Nonetheless, more research that integrates kinetics and strength assessments during non-level transfer biomechanical analyses is needed to better understand technical requirements of non-level transfers in manual wheelchair users.

A novel approach to directly measuring wheel and caster rolling resistance accurately predicts user-wheelchair system-level rolling resistance

Introduction

Clinical practice guidelines for preservation of upper extremity recommend minimizing wheelchair propulsion forces. Our ability to make quantitative recommendations about the effects of wheelchair configuration changes is limited by system-level tests to measure rolling resistance (RR). We developed a method that directly measures caster and propulsion wheel RR at a component-level. The study purpose is to assess accuracy and consistency of component-level estimates of system-level RR.

Methods

The RR of N = 144 simulated unique wheelchair-user systems were estimated using our novel component-level method and compared to system-level RR measured by treadmill drag tests, representing combinations of caster types/diameters, rear wheel types/diameters, loads, and front-rear load distributions. Accuracy was assessed by Bland-Altman limits of agreement (LOA) and consistency by intraclass correlation (ICC).

Results

Overall ICC was 0.94, 95% CI [0.91-0.95]. Component-level estimates were systematically lower than system-level (-1.1 N), with LOA +/-1.3 N. RR force differences between methods were constant over the range of test conditions.

Conclusion

Component-level estimates of wheelchair-user system RR are accurate and consistent when compared to a system-level test method, evidenced by small absolute LOA and high ICC. Combined with a prior study on precision, this study helps to establish validity for this RR test method.

Biomechanical analysis of wheelchair athletes with paraplegia during cross-training exercises

CONTEXT

Extreme conditioning programs (ECPs), such as CrossFit^®, are a relatively new method of fitness with rapid growth in individuals with paraplegia. However, it is unknown if wheelchair users are at an additional risk of musculoskeletal injury during these exercises. Biomechanical characterization is necessary to determine the safety and efficacy of ECPs as an exercise modality for wheelchair users with paraplegia.

OBJECTIVE

To characterize the three-dimensional (3-D) thorax and upper extremity joint kinematics of paraplegic wheelchair athletes during exercises commonly prescribed as part of ECPs.

DESIGN

Observational study.

PARTICIPANTS

Three male wheelchair athletes, average age of 37.1 ± 4.6 years, with spinal cord injury levels of T8, L2, and T10, with varying exercise experience.

METHODS

3-D movement was acquired using motion capture during the performance of four exercises: battle ropes, sled pull, overhead press, and sledgehammer swing. A custom upper extremity inverse kinematics model was applied to compute 3-D joint angles.

OUTCOME MEASURES

3-D peak thorax, glenohumeral, elbow, and wrist joint angles and ranges of motion (ROM), Visual Analog Scale (VAS), and Borg Scale of Perceived Exertion.

RESULTS

Large joint motions were required for the exercises, at times demanding extreme shoulder and/or wrist flexion and extension, abduction, and external rotation, which are concerning for injury risk in wheelchair users. Participants, however, were able to perform the exercises pain free.

CONCLUSION

These quantitative findings highlight that wheelchair athletes may be exposed to potentially injurious positions during common ECP exercises. These findings provide insight that may lead to improved clinical guidelines for prescription and training of exercise regimens, particularly involving ECPs, for wheelchair users.

Effect of Wheels, Casters and Forks on Vibration Attenuation and Propulsion Cost of Manual Wheelchairs

Manual wheelchair users are exposed to whole-body vibrations as a direct result of using their wheelchair. Wheels, tires, and caster forks have been developed to reduce or attenuate the vibration that transmits through the frame and reaches the user. Five of these components with energy-absorbing characteristics were compared to standard pneumatic drive wheels and casters. This study used a robotic wheelchair propulsion system to repeatedly drive an ultra-lightweight wheelchair over four common indoor and outdoor surfaces: linoleum tile, decorative brick, poured concrete sidewalk, and expanded aluminum grates. Data from the propulsion system and a seat-mounted accelerometer were used to evaluate the energetic efficiency and vibration exposure of each configuration. Equivalence test results identified meaningful differences in both propulsion cost and seat vibration. LoopWheels and SoftWheels both increased propulsion costs by 12-16% over the default configuration without reducing vibration at the seat. Frog Legs suspension caster forks increased vibration exposure by 16-97% across all four surfaces. Softroll casters reduced vibration by 11% over metal grates. Wide pneumatic 'mountain' tires showed no difference from the default configuration. All vibration measurements were within acceptable ranges compared to health guidance standards. Out of the component options, softroll casters show the most promising results for ease of efficiency and effectiveness at reducing vibrations through the wheelchair frame and seat cushion. These results suggest some components with built-in suspension systems are ineffective at reducing vibration exposure beyond standard components, and often introduce mechanical inefficiencies that the user would have to overcome with every propulsion stroke.

Hand-rim biomechanics during geared manual wheelchair propulsion over different ground conditions in individuals with spinal cord injury

Geared manual wheelchair wheels, a recently developed alternative propulsion mechanism, have the potential to alleviate the high upper extremity demands required for wheelchair propulsion and help decrease the risk of secondary injuries in manual wheelchair users. The objective of this study was to investigate the effects of using geared manual wheelchairs on hand-rim biomechanics of wheelchair propulsion in individuals with spinal cord injury (SCI). Seven manual wheelchair users with SCI propelled their wheelchairs equipped with geared wheels over tile, carpet, and up a ramp in low gear (gear ratio 1.5:1) and standard gear (gear ratio 1:1) conditions. Hand-rim kinetics and stroke cycle characteristics were measured using a custom instrumented geared wheel. Using the geared wheels in the low gear condition, propulsion speed (P = 0.013), peak resultant force (P = 0.005), peak propulsive moment (P < 0.006), and peak rate of rise of the resultant force (P = 0.035) decreased significantly in comparison with the standard gear condition. The significant increase in the number of stroke cycles when normalized to distance (P = 0.004) and decrease in the normalized integrated moment (P = 0.030) indicated that although a higher number of stroke cycles are required for travelling a given distance in the low gear than the standard gear condition, the low gear condition might be less demanding for the upper extremity. These results suggest that geared wheels could be a useful technology for manual wheelchair users to independently accomplish strenuous propulsion tasks including mobility on carpeted floors and ramp ascension, while reducing the risk factors contributing to the incidence of secondary upper extremity injuries.

Musculoskeletal Morbidity Among Adults Living With Spina Bifida and Cerebral Palsy

Background

Individuals living with cerebral palsy (CP) or spina bifida (SB) are at heightened risk for chronic health conditions that may develop or be influenced by the impairment and/or the process of aging.

Objectives

The objective of this study was to compare the incidence of and adjusted hazards for musculoskeletal (MSK) morbidities among adults living with and without CP or SB.

Methods

A retrospective, longitudinal cohort study was conducted among adults living with (n = 15,302) CP or SB and without (n = 1,935,480) CP or SB. Incidence estimates of common MSK morbidities were compared at 4 years of enrollment. Survival models were used to quantify unadjusted and adjusted hazard ratios for incident MSK morbidities. The analyses were performed in 2019 to 2020.

Results

Adults living with CP or SB had a higher 4-year incidence of any MSK morbidity (55.3% vs. 39.0%) as compared to adults without CP or SB, and differences were to a clinically meaningful extent. Fully adjusted survival models demonstrated that adults with CP or SB had a greater hazard for all MSK disorders; this ranged from hazard ratio (HR) 1.40 (95% CI, 1.33 to 1.48) for myalgia to HR 3.23 (95% CI, 3.09 to 3.38) for sarcopenia and weakness.

Conclusion

Adults with CP or SB have a significantly higher incidence of and risk for common MSK morbidities as compared to adults without CP or SB. Efforts are needed to facilitate the development of improved clinical screening algorithms and early interventions to reduce risk of MSK disease onset/progression in these higher risk populations.

Wheelchair Axle Position Effect on the Propulsion Performance of Persons With C7 Tetraplegia: A Repeated-Measures Study

Objectives

To assess the changes in speed, stroke frequency, acceleration, and shoulder range of motion (ROM) associated with different wheelchair axle positions in people with chronic C7 tetraplegia.

Methods

This repeated-measures study was conducted at the Chronic Spinal Cord Injury Unit, FLENI Escobar, Argentina. The speed, stroke frequency, acceleration, and shoulder ROM during wheelchair propulsion were measured in nine participants with C7 spinal cord injury (SCI) in four different axle positions (forward and up, forward and down, backward and down, backward and up). Two strokes performed at maximum speed were analyzed on a smooth level vinyl floor in a motion analysis laboratory. Data were analyzed for significant statistical differences using the Friedman test and the Wilcoxon signed rank test.

Results

Our study showed significant differences in the speed with axle position 1 (1.57 m/s) versus 2 (1.55 m/s) and position 2 (1.55 m/s) versus 4 (1.52 m/s). The shoulder ROM showed a significant difference in the sagittal plane in position 2 (59.34 degrees) versus 3 (61.64 degrees), whereas the stroke frequency and the acceleration parameters showed no statistically significant differences with the different rear axle positions.

Conclusions

Our study showed that modifying the rear axle position can improve the propulsion speed and produce changes in the shoulder ROM in the wheelchair propulsion of individuals with C7 SCI.

Effect of wheelchair configurations on shoulder movements, push rim kinetics and upper limb kinematics while negotiating a speed bump

This study aimed to provide a comprehensive assessment of upper limb kinetics and kinematics and shoulder movements during wheelchair propulsion while negotiating a speed bump of 6 cm height using four different wheelchair configurations. 16 healthy males aged 30.8 ± 5.7 years participated in the experiment. The kinetic and kinematic data during wheelchair propulsion were recorded. A smart system was used to collect the push forces and a motion capture system was used to collect upper limb movements. The results show that approximately 50% more pushing force was required to negotiate the speed bump than that of level ground propulsion. At the upward-forward axle position, peak total forces were 95.17 ± 5.70 N which resulted in significantly improved propulsion ergonomics, but 129.36 ± 6.68 N was required at the upward-back axle position at the speed bump push. The findings could help manufactures to design protective gloves for wheelchair users and provide useful rehabilitation information to clinicians and patients. Practitioner summary: This study investigated pushing forces and movements during wheelchair propulsion over a speed bump. Approximately 50% more pushing force was required to negotiate the bump than a level surface propulsion. The upper-forward axle position was found to be reasonably better than other positions during wheelchair propulsion. Abbreviations: UF: upper and forward position; UB: upper and back position; DF: down and forward position; DB: down and back position; ROM: range of motion.

Limb loss in individuals with chronic spinal cord injury

Objective: The purpose of this study is to describe a population of individuals with chronic spinal cord injury (SCI), who underwent lower limb amputations, identify indications for amputations, medical co-morbidities and summarize resulting complications and functional changes.Design: Retrospective observational cohort study.Setting: SCI Service, Department of Veterans Affairs (VA) Health Care System.Participants: Veterans with SCI of greater than one-year duration who underwent amputation at a VA Medical Center over a 15-year period, using patient registry and electronic health records. Diagnosis and procedure codes were utilized to identify amputations.Interventions: Not applicable.Outcome measures: Amputation level, complications, functional status, change in prescribed mobility equipment and mortality.Results: 52 individuals with SCI received amputation surgery with a mean age of 62.9 years at time of amputation. Thirty-seven (71.2%) had paraplegia, and 34 (65.3%) had motor-complete SCI. Pressure injuries and osteomyelitis were most common indications for amputation. Amputations were primarily (83%) at the transtibial level or more proximal, with the most common amputation level at transfemoral/through-knee (29;55.8%). Postoperative complications occurred in five individuals. Seven of nine individuals who were ambulatory pre-surgery remained ambulatory. Equipment modifications were required in 37 (71%) of individuals. Five-year survival following amputations was 52%, and presence of peripheral vascular disease was significantly associated with mortality (P = 0.006).Conclusions: Pressure injuries and osteomyelitis were most common etiologies for limb loss. Less than half experienced functional change after amputation; more than half required new or modified mobility equipment. An increase in mortality may reflect overall health deterioration over time.

Effect of Fatiguing Wheelchair Propulsion and Weight Relief Lifts on Subacromial Space in Wheelchair Users

Objective

This study aimed to identify targets of intervention for reducing shoulder pain in wheelchair users with spinal cord injury (SCI) by (1) examining changes in subacromial space [acromiohumeral distance (AHD) and occupation ratio (OccRatio)] with fatiguing wheelchair propulsion, and different loading conditions [unloaded position vs. weight relief lifts (WRL)]; (2) associating these changes with wheelchair user capacity, as well as (3) identifying subject characteristics associated with subacromial space, such as sex, lesion level, time since injury, body mass index and impaired shoulder range of motion.

Methods

Fifty manual wheelchair users with SCI [11 females, age = 50.5 (9.7) years, time since injury = 26.2 (11.4) years] participated in this quasi-experimental one-group pretest-posttest study. Ultrasound images were used to define AHD during an unloaded position, and during personal and instructed WRL before and after fatiguing wheelchair propulsion. Furthermore, supraspinatus and biceps thickness defined from ultrasound images were used to calculate OccRatios. Wheelchair user capacity was quantified as functional strength (maximum resultant force reached during maximum isometric forward push) and anaerobic work capacity (highest power output reached during 15-m sprint test). Multilevel mixed-effects linear regression analyses controlling for between subject variability and covariables were performed to address the research questions.

Results

AHD was significantly smaller during personal WRL (p &lt; 0.001) and instructed WRL (p = 0.009, AHD both 11.5 mm) compared to the unloaded position (11.9 mm). A higher wheelchair user capacity (higher anaerobic work capacity) reduced the impact of WRL on AHD decrease. The fatiguing wheelchair propulsion had no effect on AHD (p = 0.570) and on OccRatio of supraspinatus (p = 0.404) and biceps (p = 0.448). Subject characteristics related to a larger subacromial space were lower lesion level, shorter time since injury, impaired external rotation, a lower body mass index and a higher anaerobic work capacity.

Conclusion

This study showed a significant reduction in AHD during WRL with no effect of fatiguing wheelchair propulsion on the subacromial space in wheelchair users with SCI. A higher anaerobic work capacity was beneficial in stabilizing the shoulder during WRL. Our findings may assist clinicians in designing a shoulder injury prevention program.

Effectiveness of Rehabilitation through Kinematic Analysis of Upper Limb Functioning in Wheelchair Basketball Athletes: A Pilot Study

Wheelchair basketball is one of the most popular Paralympic sports, including players with different diagnoses. To date, there is scarce evidence on shoulder functionality in wheelchair basketball players, and there is no consensus on a shoulder injury prevention program in these athletes. Therefore, in the present pilot study, we aimed to evaluate the effects of a comprehensive rehabilitative approach on shoulder ROM, muscle activity, and functioning in wheelchair basketball athletes. We included adult wheelchair basketball athletes playing in the Italian Second League who completed an 8-week comprehensive rehabilitative program, based on education to avoid upper limb pain injuries, preventive exercises, and improvement of ergonomics through kinematic analysis. We administered the Wheelchair User’s Shoulder Pain Index (WUSPI) and the Kerlan-Jobe Orthopaedic Clinic (KJOC) questionnaire to evaluate pain experienced during functional activities, and used kinematic analysis integrated with sEMG to evaluate shoulder function and propulsion pattern. A sample of 10 wheelchair athletes (33.75 ± 6.42 years) were assessed. After the intervention there was a significant (p < 0.05) difference in WUSPI score (27.0 ± 18.5 vs. 25.0 ± 21.5) and in KJOC score (89.3 ± 10.4 to 95.4 ± 9.1). Moreover, there was a significant improvement in scapular upward rotation, abduction, and extra-rotation of the glenohumeral joint. Propulsion techniques improved in pattern and acceleration. This approach played a key role in improving upper limb function, reducing the incidence of pain and cumulative trauma disorders. However, the small sample size could affect the generalizability of results. In conclusion, healthcare professionals should monitor wheelchair athletes, assessing the patient’s function, ergonomics, equipment, and level of pain, and introducing specific exercises to prevent upper limb injuries.

Learning of Wheelchair Racing Propulsion Skills Over Three Weeks of Wheeling Practice on an Instrumented Ergometer in Able-Bodied Novices

The acquisition of daily handrim wheelchair propulsion skill as a multi-layered phenomenon has been studied in the past. Wheelchair racing, however, is considerably different from daily handrim wheelchair propulsion in terms of propulsion technique, as well as the underlying equipment and interface. Understanding wheelchair racing skill acquisition is important from a general motor learning and skill acquisition perspective, but also from a performance and injury prevention perspective. The aim of the current lab-based study was 2-fold: to investigate the evolution of racing wheelchair propulsion skill among a sample of novices and to compare them with an experienced wheelchair racer under similar conditions. A convenience sample of 15 able-bodied novices (8 male, 7 female) completed a standardized three-week submaximal uninstructed practice protocol (3 weeks, 3 sessions per week, 3x4 min per session) in a racing wheelchair on an ergometer. Required wheeling velocity was set at 2.78 m/s (10 km/h) and a rolling friction coefficient of 0.011 (resulting in a mean target load of 21W) was used. For comparison, an experienced T54 Paralympic athlete completed one block of the same protocol. Kinetics, kinematics, and physiological data were captured. A mixed effects regression analysis was used to examine the effect of practice for the novices, while controlling for speed. All participants finished the protocol successfully. However, not all participants were able to achieve the target speed during the first few sessions. Statistically significant improvements over time were found for all outcome measures (i.e., lower metabolic strain, longer push and cycle times) with the exception of mean power and torque per push. The athlete used a significantly greater contact angle and showed “better” outcomes on most metabolic and kinetic variables. While the athlete used a semi-circular propulsion technique, most participants used a double looping over technique. Three weeks of uninstructed wheelchair racing practice significantly improved efficiency and skill among a group of novices, in line with previous studies on daily handrim wheelchair propulsion. The comparison with an experienced athlete expectedly showed that there is still a large performance (and knowledge) gap to be conquered.

Acute physiological comparison of sub-maximal exercise on a novel adapted rowing machine and arm crank ergometry in people with a spinal cord injury

Study design

Non-randomized crossover trial.

Objectives

The objective of this study was to assess the oxygen uptake during exercise using the Adapted ROWing machine (AROW) compared to the more commonly used Arm Crank Ergometry (ACE) for people with spinal cord injury/disease (SCI/D) with or without trunk stability.

Setting

Canada, Vancouver.

Methods

Participants were from a convenience sample of 14 adults with SCI/D (age 21–63 y) which include those with lumbar to low cervical impairments currently exercising at least once per week using cardiovascular exercise equipment at our Physical Activity Research Centre. The interventions were non-randomized steady-state exercise bouts at self-selected low and moderate workloads on the AROW and ACE for 5 min each. Our primary outcomes were the rate of oxygen consumption (mL/kg/min) and the Borg 0–10 Rating Scale of Perceived Exertion (RPE).

Results

A repeated measures two-way ANOVA (p < 0.05) indicated that exercising on the AROW resulted significantly greater oxygen consumption and perceived exertion than ACE at similar sub-maximal workloads which may be explained by the differences in efficiency between the devices (Partial eta squared = 0.84, F stat = 48.25; Partial eta squared = 0.86, F stat = 53.54).

Conclusions

We have demonstrated that this form of upper extremity exercise had a greater RPE and VO₂ on the ACE at a given workload. Thus, the AROW could provide a functional upper extremity workout that can be used for daily exercise for those with varying levels of SCI.

Glenohumeral joint dynamics and shoulder muscle activity during geared manual wheelchair propulsion on carpeted floor in individuals with spinal cord injury

This study investigated the effects of using geared wheels on glenohumeral joint dynamics and shoulder muscle activity during manual wheelchair propulsion. Seven veterans with spinal cord injury propelled their wheelchairs equipped with geared wheels over a carpeted floor in low gear (1.5:1) and standard gear (1:1) conditions. Hand-rim kinetics, glenohumeral joint dynamics, and muscle activity were measured using a custom instrumented geared wheel, motion analysis, and surface electromyography. Findings indicated that the propulsion speed and stroke distance decreased significantly during the low gear condition. The peak hand-rim resultant force and propulsive moment, as well as the peak glenohumeral inferior force and flexion moment, were significantly less during the low gear condition. The peak and integrated muscle activity of the anterior deltoid and pectoralis major decreased significantly, while the normalized integrated muscle activity (muscle activity per stroke distance) was not significantly different between the two conditions. Propulsion on carpeted floor in the low gear condition was accompanied by a reduced perception of effort. The notable decrease in the peak shoulder loading and muscle activity suggests that usage of geared wheels may be beneficial for wheelchair users to enhance independent mobility in their homes and communities while decreasing their shoulder demands.

Comparison of glenohumeral joint kinematics between manual wheelchair tasks and implications on the subacromial space: A biplane fluoroscopy study

Scapula and humerus motion associated with common manual wheelchair tasks is hypothesized to reduce the subacromial space. However, previous work relied on either marker-based motion capture for kinematic measures, which is prone to skin-motion artifact; or ultrasound imaging for arthrokinematic measures, which are 2D and acquired in statically-held positions. The aim of this study was to use a fluoroscopy-based approach to accurately quantify glenohumeral kinematics during manual wheelchair use, and compare tasks for a subset of parameters theorized to be associated with mechanical impingement. Biplane images of the dominant shoulder were acquired during scapular plane elevation, propulsion, sideways lean, and weight-relief raise in ten manual wheelchair users with spinal cord injury. A computed tomography scan of the shoulder was obtained, and model-based tracking was used to quantify six-degree-of-freedom glenohumeral kinematics. Axial rotation and superior/inferior and anterior/posterior humeral head positions were characterized for full activity cycles and compared between tasks. The change in the subacromial space was also determined for the period of each task defined by maximal change in the aforementioned parameters. Propulsion, sideways lean, and weight-relief raise, but not scapular plane elevation, were marked by mean internal rotation (8.1°, 10.8°, 14.7°, -49.2° respectively). On average, the humeral head was most superiorly positioned during the weight-relief raise (1.6 ± 0.9 mm), but not significantly different from the sideways lean (0.8 ± 1.1 mm) (p = 0.191), and much of the task was characterized by inferior translation. Scaption was the only task without a defined period of superior translation on average. Pairwise comparisons revealed no significant differences between tasks for anterior/posterior position (task means range: 0.1-1.7 mm), but each task exhibited defined periods of anterior translation. There was not a consistent trend across tasks between internal rotation, superior translation, and anterior translation with reductions in the subacromial space. Further research is warranted to determine the likelihood of mechanical impingement during these tasks based on the measured task kinematics and reductions in the subacromial space.

Lifestyle physical activity in manual wheelchair users - an overlooked public health opportunity

Public health guidelines and health promotion efforts have traditionally focused on weekly accumulation of moderate to vigorous physical activity (MVPA) via structured exercise. There has been a recent paradigm shift towards the organic incorporation of MVPA in daily leisure and non-leisure time, termed "Lifestyle Physical Activity" (LPA). However, this paradigm shift and the underlying research has neglected manual wheelchair users (MWCUs) with spinal cord injury (SCI), who could benefit from LPA. This article argues for expanding the LPA paradigm shift into research and health promotion efforts involving MWCUs with SCI. We suggest a working definition of LPA for MWCUs and candidate metrics for quantifying LPA. This is followed by brief overviews of LPA correlates, outcomes/consequences, and interventions and the need for theory based approaches to study these domains. We lastly suggest an approach for mitigating potential negative outcomes of increased LPA in MWCUs and suggest a research agenda.

Ultrasound-guided platelet-rich plasma injection for the treatment of recalcitrant rotator cuff disease in wheelchair users with spinal cord injury: A pilot study

Context/Objective: Wheelchair users with spinal cord injury (SCI) have a high risk of developing shoulder pain, caused by rotator cuff disease. Platelet-rich plasma (PRP) is a potential treatment after conservative treatments fail and prior to surgical intervention; however, it has not been tested in wheelchair users who have recalcitrant shoulder pain associated with rotator cuff disease. The objective of this pilot project was to test the safety and potential treatment effect of an ultrasound-guided PRP injection for shoulder pain in the aforementioned population.Design: Prospective, quasi-experimental.Setting: Clinical research center.Participants: Six wheelchair users with SCI (3 paraplegia, 3 tetraplegia) who had chronic shoulder pain due to rotator cuff disease (presence of anterior shoulder pain, positive physical examination tests for rotator cuff disease, and tendinopathy demonstrated by ultrasound) and failed at least six months of conservative treatment.Interventions: Ultrasound-guided PRP injection into pathological shoulder tendons, targeting the supraspinatus. Subjects were provided a standardized stretching and strengthening program and were followed for 4, 8, 12, and 24 weeks post-intervention with outcomes collected at each time-point.Outcome Measures: Wheelchair User's Shoulder Pain Index (WUSPI); pain Numerical Rating Scale (NRS); physical and ultrasound examinations for supraspinatus tendinopathy; 5-point patient global impression of change (PGIC).Results: WUSPI (69.9%, P < 0.001), NRS (49.6%, P < 0.01), and physical exam scores (35.7%, P < 0.01) decreased 24 weeks after treatment. Participants reported overall improvement in their status as a result of the treatment. No adverse events were noted, and no changes in ultrasound markers for tendinopathy were observed.Conclusion: A single, ultrasound-guided PRP injection into the supraspinatus tendon, followed by a stretching and strengthening exercise program, was safe and provided improvements in shoulder pain outcome measures in this sample for 24 weeks. Lack of blinding, short-term follow-up, and a suitable control group warrant a larger randomized controlled trial.Trial Registration: NCT01355549.

Impact of dribbling on spatiotemporal and kinetic parameters in wheelchair basketball athletes

BACKGROUND

Wheelchair basketball is one of the most popular Paralympic sports. Dribbling a ball while propelling is a key feature of wheelchair basketball. Very few studies have investigated the biomechanical impact of dribbling. This study aims to analyze the impact of dribbling on the amplitude and symmetry of spatiotemporal and kinetic parameters of wheelchair propulsion.

METHODS

Ten experienced wheelchair basketball athletes (31.5 ± 10.6 years old; 7 men, 3 women) with various classifications performed eight 9-m sprints along a straight line on a basketball court: four sprints using classic synchronous propulsion, and four sprints while dribbling a ball down the court.

FINDINGS

Dribbling decreased velocity, mean propulsive moments and the force rate of rise, as well as increased push time, force rate of rise asymmetry and angular impulse asymmetry. All kinetic variables were asymmetric and higher on the dominant limb.

INTERPRETATION

The combination of reduced velocity and propulsive moments when dribbling indicates that wheelchair basketball athletes may deliberately preserve a safety margin of acceleration to adapt to uncontrolled ball rebounds. Dribbling was not associated with any factors associated with an increased risk of musculoskeletal disorders.

Detecting clinical practice guideline-recommended wheelchair propulsion patterns with wearable devices following a wheelchair propulsion intervention

Wheelchair propulsion interventions typically teach manual wheelchair users to perform wheelchair propulsion biomechanics as recommended by the Clinical Practice Guidelines (CPG). Outcome measures for these interventions are primarily laboratory based. Discrepancies remain between manual wheelchair propulsion (MWP) in laboratory-based examinations and propulsion in the real-world. Current developments in machine learning (ML) allow for monitoring of MWP in the real world. In this study, we collected data from participants enrolled in two wheelchair propulsion interventions, then built an ML algorithm to distinguish CPG recommended MWP patterns from non-CPG-recommended patterns. Eight primary manual wheelchair users did not initially follow CPG recommendations but learned and performed CPG propulsion after the interventions. Participants each wore two inertial measurement units as they propelled their wheelchairs on a roller system, indoors overground, and outdoors. ML models were trained to classify propulsion patterns as following the CPG or not following the CPG. Video recordings were used for reference. For indoor detection, we found that a subject-independent model was able to achieve 85% accuracy. For outdoor detection, we found that the subject-independent model achieved 75.4% accuracy. These results provide further evidence that CPG and non-CPG-recommended MWP patterns can be predicted with wearable sensors using an ML algorithm.

Temporo-spatial parameters, shoulder kinematics and acute tendon changes in four different stroke patterns in men wheelchair users with spinal cord injury

BACKGROUND

Manual wheelchair propulsion causes the shoulder tendon pathologies in wheelchair users with spinal cord injury due to its repetitive nature. Four different wheelchair stroke patterns can cause varying amounts of acute changes in the shoulder tendons.

OBJECTIVE

To evaluate and compare acute changes in the supraspinatus and biceps tendons and acromio-humeral distance (AHD) after propulsion between different stroke patterns in individuals with spinal cord injury. Additionally, to associate tendon changes with demographic and biomechanical characteristics.

DESIGN

Prospective and comparative study between four groups.

SETTING

Tertiary rehabilitation hospital.

PATIENTS

Men wheelchair users with spinal cord injury.

INTERVENTIONS

Participants were divided into 4 groups according to stroke pattern (arcing, semicirculer (SC), single-loop (SL) and double-loop (DL)), in which they used their wheelchair on a motorized treadmill at a speed of 1 m/s. A sample of 40 people was created, 10 in each group. All participants performed a propulsion test.

MAIN OUTCOME MEASURES

Temporo-spatial variables and shoulder kinematics were analyzed. Supraspinatus tendon thickness (SSTT), long head of biceps tendon thickness (LHBTT) and AHD were measured before and after the propulsion test.

RESULTS

SC pattern had lower cadance and larger contact angle. A reduction in SSTT and LHBTT in arcing pattern, LHBTT and AHD in SC pattern and, LHBTT in DL pattern was observed (all P < 0.05). However, SL pattern did not differ significantly in all ultrasonographic measurements (all P > 0.05). Body mass index was associated with a decrease in SSTT. Age and number of daily push-up were associated with a decrease in AHD.

CONCLUSIONS

Less tendon changes after the propulsion in the SL pattern suggested that the supraspinatus and biceps tendons were preserved in this pattern. The SL pattern may be a better choice for men wheelchair users with supraspinatus and biceps tendon pathologies. This article is protected by copyright. All rights reserved.

Handrim forces during wheelies performance in able-bodied and SCI subjects

Context: Manual wheelchair users must be able to carry out wheelies in order to tackle obstacles in the outdoor environment. To date, no studies have compared balance variables and forces exerted on the handrim during a stationary wheelie between able bodied and spinal cord injury subjects.Objectives: To compare the distribution of forces applied to the handrim and the center of pressure displacement during a stationary wheelie between able-bodied (AB) subjects and manual wheelchair users with spinal cord injury (SCI).Design: Prospective experimental study.Setting: A university hospital laboratory.Participants: 27 participants (14 AB and 13 SCI).Outcome Measure: Each participant performed 3 stationary wheelies of 60 s duration using a wheelchair equipped with an instrumented wheel. Two force platforms were used to calculate the displacement of the center of pressure (DCOP).Results: Median group DCOP amplitude in the anteroposterior axis was smaller and less variable in the AB (19.6 mm [8.1,49.6]) than the SCI (14.9 mm [7.6,141.1]) group. Forces applied to the handrim only differed significantly between the AB (6 N [-13.8,16.6]) and SCI groups (2.7 N [-12.1 21.9]) in the posteroanterior axis.Conclusions: The results showed that the participants with SCI exerted greater PA forces on the handrim, moreover, the direction of force was opposite to that of the AB group, suggesting that the SCI group used a proactive balance strategy while the AB group used a retroactive strategy. The results suggest that the direction of force applied should be considered when teaching individuals to perform wheelies.

A pilot study to evaluate micro-fragmented adipose tissue injection under ultrasound guidance for the treatment of refractory rotator cuff disease in wheelchair users with spinal cord injury

CONTEXT/OBJECTIVES

Wheelchair users with chronic shoulder pain have few options after conservative treatments fail. This pilot study's purpose was to establish safety and treatment effects of micro-fragmented adipose tissue (MFAT) injections under ultrasound guidance for treatment of refractory shoulder pain caused by rotator cuff disease in wheelchair users with spinal cord injury (SCI) to prepare for a larger trial.

DESIGN

Pilot clinical trial.

SETTING

Rehabilitation hospital outpatient clinic.

PARTICIPANTS

Ten wheelchair users with chronic SCI who had moderate-to-severe shoulder pain caused by refractory rotator cuff disease (diagnosed via ultrasound) for greater than 6 months.

INTERVENTIONS

Ultrasound-guided injections of MFAT into the pathologic rotator cuff tendons and other abnormal shoulder structures (e.g. acromioclavicular and glenohumeral joints; subacromial bursa).

OUTCOME MEASURES

6- and 12-month changes in 11-point Numerical Rating Scale (NRS); Wheelchair User's Shoulder Pain Index (WUSPI); Brief Pain Inventory pain interference items (BPI-I7); Patient Global Impression of Change (PGIC); ultrasound and physical exams; and adverse events.

CONCLUSIONS

There were no significant adverse events throughout the study period. WUSPI, NRS, and BPI-I7 scores were significantly lower 6 and 12 months post-procedure (P < .05). Of those who remained in the trial, clinically meaningful changes (≥30% decrease) in WUSPI, NRS, and BPI-I7 scores were observed in 77.8%, 77.8%, and 66.7% of participants, respectively. All but one participant reported improvement in clinical status. MFAT injection under ultrasound guidance is potentially a safe and efficacious treatment for refractory shoulder pain caused by rotator cuff disease in wheelchair users with SCI. A larger, randomized controlled trial has been initiated.Trial registration: ClinicalTrials.gov identifier: NCT03167138.

The effect of intermittent theta burst stimulation on corticomotor excitability of the biceps brachii in nonimpaired individuals

Intermittent theta burst stimulation (iTBS) is a form of repetitive transcranial magnetic stimulation (TMS) that can increase corticomotor excitability in distal upper limb muscles, but the effect on the more proximal biceps is unknown. The study objective was to determine the effect of iTBS on corticomotor excitability of the biceps brachii in non-impaired individuals. Ten individuals completed three sessions, and an additional ten individuals completed one session in a secondary study; each session included sham and active iTBS. Resting and active motor thresholds (RMT, AMT) were determined prior to sham and active iTBS. Motor evoked potentials (MEPs) in response to single pulse TMS served as our measure of corticomotor excitability. In our primary cohort, MEPs were recorded with biphasic stimulation to accurately capture the same neurons affected by biphasic iTBS. MEPs were recorded at an intensity of 120% of RMT, or for instances of high RMTs, 100% of the maximum stimulator output (MSO), at baseline, and 10, 20, and 30 minutes after iTBS. MEPs were normalized by the maximum voluntary isometric muscle activity. In the secondary, MEPs were recorded with monophasic stimulation, which increased our ability to record MEPs at 120% of RMT. Linear mixed effects models were used to determine the effect of iTBS on normalized MEPs (nMEPs), with analyses to evaluate the interaction of the biceps AMT:RMT ratio as a measure of corticomotor conductance. Change in nMEPs from baseline did not differ for the active and sham conditions (p = 0.915 ) when MEPs were assessed with biphasic stimulation. With MEPs assessed by monophasic stimulation, there was an increase in biceps nMEPs after active iTBS, and no change in nMEPs after sham. Our results suggest that when RMTs are expected to be high when measured with biphasic stimulation, monophasic stimulation can better capture changes in MEPs induced by iTBS, and biphasic stimulation appears limited in its ability to capture changes in biceps MEPs in nonimpaired individuals. In both cohorts, increased corticomotor excitability after iTBS occurred when the biceps AMT:RMT ratio was high. Thus, the AMT:RMT ratio may be a predictive measure to evaluate the potential for iTBS to increase biceps corticomotor excitability.

Augmented feedback for manual wheelchair propulsion technique training in a virtual reality simulator

BACKGROUND

Motor learning of appropriate manual wheelchair propulsion is critical, as incorrect technique elevates risk for upper extremity pain. Virtual reality simulators allow users to practice this complex task in a safe and realistic environment. Additionally, augmented feedback (AF) may be provided in order to optimize learning. The purpose of this study was to investigate the effects of providing AF with various delivery schedules on motor learning and transfer of this skill to over-ground propulsion.

METHODS

Thirty healthy young adults were randomly assigned to three groups. During a virtual reality propulsion training session, the high-frequency AF group received AF in the form of knowledge of performance throughout all propulsion training; the faded AF group received this AF in a faded schedule (high relative frequency of AF early in practice, with relative frequency of AF provision diminishing throughout practice); and the control group underwent training with no AF. Propulsion assessments were performed at baseline and 48 h after practice in both virtual and real environments to measure retention and transfer, respectively.

RESULTS

Compared to the control group, both feedback groups exhibited significant improvements in contact angle and push frequency in both environments after training. Small, non-significant between-group differences were also found between the high-frequency and faded feedback groups.

CONCLUSION

Virtual reality training is an effective learning intervention for acquisition, retention, and transfer of appropriate manual wheelchair propulsion technique when such training includes AF regarding propulsion biomechanics.

Handgrip Strength Cutoff Points for Functional Independence and Wheelchair Ability in Men With Spinal Cord Injury

Objectives

To determine optimal handgrip strength (HGS) cutoff points for greater functional independence and wheelchair skills in men with spinal cord injury (SCI), and to establish predictive equations for functional independence and wheelchair ability in men with SCI, based on demographic characteristics, HGS, and functionality.

Methods

In this cross-sectional study conducted at a rehabilitation hospital, 54 men with SCI were recruited and stratified into high and low paraplegia groups. All participants performed a maximum HGS test to determine cutoff points for the Spinal Cord Independence Measure (SCIM-III) and Adapted Manual Wheelchair Circuit (AMWC). The primary outcomes were the SCIM-III, AMWC, and HGS. Demographic characteristics obtained from participants' electronic medical records were the secondary outcomes, used as predictor variables of functional independence.

Results

The SCIM-III scale, performance score, and 3-minute overground wheeling test presented significant regression equations (R = 0.45, R = 0.69, and R = 0.72). The HGS showed a cutoff point of 102.5 kilogram force (kgf) to achieve a score of 70 on the SCIM-III and a 3-minute overground wheeling distance of 270 m. The HGS cutoff point to obtain a performance score of 23.7 seconds was 93.0 kgf.

Conclusion

The HGS was a significant predictor for the SCIM-III score, AMWC performance score, and 3-minute overground wheeling test. Three significant predictive equations were established based on HGS. The cutoff points could be adopted as parameters for optimal functional independence and wheelchair skills.

Rolling resistance of casters increases significantly after two years of simulated use

Introduction

Manual wheelchair propulsion is associated with upper limb pain and injury, and clinical guidelines recommend minimizing propulsive force to lower health risks. One of the strategies to reduce propulsive force is by minimizing rolling resistance (RR). Product testing studies suggest that RR of casters is affected by wear and tear which could have implications on the health risk of wheelchair users. The study will investigate the relationship between caster RR and environmental exposure using standard testing protocols.

Methods

RR of ten casters representing a range of diameters for different models of wheelchairs were measured before and after environmental exposure that includes corrosion, shock and abrasion simulating two years of community use.

Results

Four casters exhibited failures during durability testing, one catastrophically. Increases to RR after corrosion, shock and abrasion exposure were statistically significant using mixed-effects modeling, and four casters had increased RR greater than 20%.

Conclusions

Many of the casters evaluated exhibited increased RR forces and failure after environmental exposure. Improved caster design and use of corrosion resistant materials may reduce these failures. In addition, modification of the provision process could include replacement casters to reduce failures and avoid breakdowns that leave manual wheelchair users stranded or injured.

Motion sickness and sense of presence in a virtual reality environment developed for manual wheelchair users, with three different approaches

Visually Induced Motion Sickness (VIMS) is a bothersome and sometimes unsafe experience, frequently experienced in Virtual Reality (VR) environments. In this study, the effect of up to four training sessions to decrease VIMS in the VR environment to a minimal level was tested and verified through explicit declarations of all 14 healthy participants that were recruited in this study. Additionally, the Motion Sickness Assessment Questionnaire (MSAQ) was used at the end of each training session to measure responses to different aspects of VIMS. Total, gastrointestinal, and central motion sickness were shown to decrease significantly by the last training session, compared to the first one. After acclimatizing to motion sickness, participants' sense of presence and the level of their motion sickness in the VR environment were assessed while actuating three novel and sophisticated VR systems. They performed up to four trials of the Illinois agility test in the VR systems and the real world, then completed MSAQ and Igroup Presence Questionnaire (IPQ) at the end of each session. Following acclimatization, the three VR systems generated relatively little motion sickness and high virtual presence scores, with no statistically meaningful difference among them for either MSAQ or IPQ. Also, it was shown that presence has a significant negative correlation with VIMS.

The Influence of Sex on Upper Extremity Joint Dynamics in Pediatric Manual Wheelchair Users With Spinal Cord Injury

INTRODUCTION

Manual wheelchair propulsion is a physically demanding task associated with upper extremity pain and pathology. Shoulder pain is reported in over 25% of pediatric manual wheelchairs users, and this number rises over the lifespan. Upper extremity biomechanics in adults has been associated with shoulder pain and pathology; however, few studies have investigated upper extremity joint dynamics in children. Furthermore, sex may be a critical factor that is currently unexplored with regard to pediatric wheelchair mobility.

OBJECTIVES

To investigate differences in upper extremity joint dynamics between pediatric male and female manual wheelchair users with spinal cord injury (SCI) during wheelchair propulsion.

METHODS

Novel instrumented wheelchair hand-rims synchronized with optical motion capture were used to acquire upper extremity joint dynamics of 20 pediatric manual wheelchair users with SCI (11 males, 9 females). Thorax, sternoclavicular, acromioclavicular, glenohumeral, elbow, and wrist joint kinematics and kinetics were calculated during wheelchair propulsion. Linear mixed models were used to assess differences between sexes.

RESULTS

Females exhibited significantly greater peak forearm pronation (p = .007), normalized wrist lateral force (p = .03), and normalized elbow posterior force (p = .04) than males. Males exhibited significantly greater peak sternoclavicular joint retraction (p < .001) than females. No significant differences between males and females were observed for the glenohumeral joint (p > .012).

CONCLUSION

This study found significant differences in upper extremity joint dynamics between sexes during manual wheelchair propulsion. Our results underscore the importance of considering sex when evaluating pediatric wheelchair mobility and developing comprehensive wheelchair training interventions for early detection and prevention of upper extremity pain and pathology.