Ursina Arnet | Swiss Paraplegic Research AG (original) (raw)

Papers by Ursina Arnet

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

Frontiers in Rehabilitation Sciences

ObjectiveThis study aimed to identify targets of intervention for reducing shoulder pain in wheel... more ObjectiveThis 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.MethodsFifty 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, supraspina...

Research paper thumbnail of Effect of fatiguing wheelchair propulsion on risk factors for shoulder pain in persons with spinal cord injury

<strong>Background:</strong> Shoulder pain is commonly reported within the spinal cor... more <strong>Background:</strong> Shoulder pain is commonly reported within the spinal cord injury (SCI) population and can have a detrimental impact on one's functioning, participation, and quality of life. Although wheel-chair propulsion is a highly inefficient mode of mobility and places the shoulder at risk for injury, it is one of the most important and most frequently used mobility devices. The mobile shoulder, compro-mised in mobility, relies on muscles and tendons to stabilise the joint. However, these muscles are prone to fatigue; how fatiguing propul-sion modifies biomechanics and muscular activation and relates to pathology and injury risk is poorly understood. <strong>Overall objective:</strong> To examine the effect of fatiguing wheelchair pro-pulsion on risk factors for shoulder pain in persons with SCI. The specific aims are threefold:1. To describe the prevalence of musculoskeletal shoulder pain and associated factors in the Swiss SCI population - Study 1 2. To define how fatiguing wheelchair propulsion changes biome-chanical and neuromuscular risk factors for shoulder pain in per-sons with SCI - Study 2 and Study 33. To evaluate how acute changes in tendon appearance with fa-tiguing wheelchair propulsion are associated with risk factors for shoulder pain in persons with SCI - Study 4. <strong>Methods: </strong>The first study used data from the Swiss SCI cohort study (SwiSCI) Community Survey database and investigated a large popu-lation based sample including persons with SCI living in Switzerland (n = 1549). The following quasi-experimental studies had a pre-test, post-test design, and examined the effect of fatiguing wheelchair pro-pulsion in wheelchair users with SCI via the implementation of an intervention of 15 minutes wheelchair propulsion including right and left turns, starts and stops, and rest periods. The second study defined how fatigue altered start-up propulsion biomechanics (n = 26). The third and fourth study were addressed with a SwiSCI nested project (n = 50). The third study defin [...]

Research paper thumbnail of Force application during handcycling and handrim wheelchair propulsion: an initial comparison

Journal of Applied Biomechanics, Jan 18, 2013

The aim of the study was to evaluate the external applied forces, the effectiveness of force appl... more The aim of the study was to evaluate the external applied forces, the effectiveness of force application and the net shoulder moments of handcycling in comparison with handrim wheelchair propulsion at different inclines. Ten able-bodied men performed standardized exercises on a treadmill at inclines of 1%, 2.5% and 4% with an instrumented handbike and wheelchair that measured three-dimensional propulsion forces. The results showed that during handcycling significantly lower mean forces were applied at inclines of 2.5% (P < .001) and 4% (P < .001) and significantly lower peak forces were applied at all inclines (1%: P = .014, 2.5% and 4%: P < .001). At the 2.5% incline, where power output was the same for both devices, total forces (mean over trial) of 22.8 N and 27.5 N and peak forces of 40.1 N and 106.9 N were measured for handbike and wheelchair propulsion. The force effectiveness did not differ between the devices (P = .757); however, the effectiveness did increase with ...

Research paper thumbnail of Shoulder Tendon Adaptations Following a Graded Exercise Test to Exhaustion in Highly Trained Wheelchair Rugby Athletes With Different Impairments

Frontiers in Rehabilitation Sciences

ObjectiveThis study aimed to identify acute changes in biceps and supraspinatus tendon characteri... more ObjectiveThis study aimed to identify acute changes in biceps and supraspinatus tendon characteristics before and after a graded exercise test to exhaustion (GXT) in highly trained wheelchair rugby (WR) athletes. A secondary aspect was to define chronic tendon adaptations related to the impairment of the athlete and the occupation of the tendon within the subacromial space (occupation ratio).MethodsTwelve WR athletes with different impairments (age = 32 ± 6 years; body mass = 67.2 ± 11.2 kg; 9.0 ± 3.6 years competing) volunteered for this study. Performance Corrected Wheelchair Users Shoulder Pain Index was used to quantify shoulder pain. Quantitative Ultrasound Protocols (QUS) were used to define supraspinatus and biceps tendon thickness, echogenicity, and echogenicity ratio of both dominant and non-dominant shoulder before and after the GXT including 22 ± 3.1 min submaximal propulsion and 10.2 ± 1.7 min maximal propulsion on a treadmill. Furthermore, the acromio-humeral distance (...

Research paper thumbnail of Handbiking: a biophysical analysis

Research paper thumbnail of Unilateral Shoulder Pain is Associated with Asymmetries in Tendon Thickness Following Maximum Exertion in an Elite Wheelchair Rugby Athlete: A Case in Point Towards Individualized Feedback

The purpose of this study was to describe changes in tendon thickness following maximum exertion ... more The purpose of this study was to describe changes in tendon thickness following maximum exertion in the symptomatic and asymptomatic shoulder of a highly trained wheelchair rugby athlete with tetraplegia. Tendon thickness of the biceps and supraspinatus on both sides were measured with ultrasound before any physical tests, after a treadmill test up to maximum exertion to define aerobic capacity, and after a 30s Wingate test to define anaerobic capacity. The athlete reported moderate to severe shoulder pain, quantified with the upper extremity pain symptom questionnaire (PSQ) on the left shoulder and no pain on the right shoulder. There was a meaningful reduction (i.e., > 2 x SD) in biceps and supraspinatus tendon thickness after the physical tests at the asymptomatic shoulder with no meaningful changes at the symptomatic shoulder. Reduction in tendon thickness has been related to increased alignment of the collagen fibres or creep which is a typical response to tensile loading. W...

Research paper thumbnail of Is Synchronous Handcycling Less Straining Than Handrim Wheelchair Propulsion ?

INTRODUCTION The upper extremities especially the shoulders are at serious risk for overuse in ha... more INTRODUCTION The upper extremities especially the shoulders are at serious risk for overuse in handrim wheelchair users. It has been shown that upper extremity complaints frequently occur within the wheelchair user population [1]. However, physical activity and an active lifestyle are important to maintain general fitness and to prevent long term health problems. Because handrim wheelchair propulsion has been shown to be an inefficient and mechanically straining form of ambulation [2], alternative propulsion mechanisms have been developed and studied. The handcycle has been proven to be an energetically more efficient and less straining alternative to the wheelchair [3]. However, the magnitude of the mechanical load of handcycling has not been subject of report. Due to the fact that the external power output needed for propulsion is produced with a considerably larger muscle mass, the mechanical load of handcycling on the upper extremity is believed to be lower.

Research paper thumbnail of MRI evaluation of shoulder pathologies in wheelchair users with spinal cord injury and the relation to shoulder pain

The journal of spinal cord medicine, 2021

OBJECTIVE To describe the number, specifics and co-occurrence of shoulder pathologies detected by... more OBJECTIVE To describe the number, specifics and co-occurrence of shoulder pathologies detected by MRI in manual wheelchair users with spinal cord injury and to evaluate the association between shoulder pathologies and presence of shoulder pain. DESIGN Cross-sectional observation study. SETTING Community. PARTICIPANTS Fifty-one wheelchair-dependent persons with spinal cord injury (44 males, 7 females, median age 50 years (IQR 14), median time since injury 24 years (IQR 16)) were allocated to pain or no-pain group based on the Wheelchair User Shoulder Pain Index. INTERVENTIONS Not applicable. OUTCOME MEASURES All persons underwent shoulder MRI. Pathologies were scored blinded by two experienced radiologists. Participant characteristics, number and severity of shoulder pathologies were analyzed descriptively. Logistic regression was performed to evaluate the association between MRI findings and shoulder pain. RESULTS The median number of co-occurring MRI findings per person ranged from...

Research paper thumbnail of Surgical Reconstruction of Intrinsic Muscle Function in Tetraplegia : Comparison of Techniques

The aim of this study was to analyze the contribution of the intrinsics (INT) to a functional han... more The aim of this study was to analyze the contribution of the intrinsics (INT) to a functional hand closing and to compare the results of two INT reconstruction techniques (ZancolliLasso and House procedures). Kinematics of cadaveric hands during hand closing (FDP tendon pulled by a motor) were analyzed at following conditions: no activation of INT, high activation of INT and reconstruction of INT by Zancolli-Lasso or House technique. The results showed that INT activation results in a more functional hand closing represented by a larger fingertip-topalm distance. Both reconstruction techniques showed improved grasp capacity in comparison to the nonreconstructed hand. However, only the House procedure restored hand kinematics resembling those of an active INT hand.

Research paper thumbnail of Shoulder Load in Handbike and Handrim Wheelchair Propulsion

1,2 Ursina Arnet, 1,2 Stefan van Drongelen, 3 Luc van der Woude and 2, 4 DirkJan Veeger 1 Swiss P... more 1,2 Ursina Arnet, 1,2 Stefan van Drongelen, 3 Luc van der Woude and 2, 4 DirkJan Veeger 1 Swiss Paraplegic Research, Nottwil, Switzerland, 2 Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands, 3 Center for Human Movement Sciences, Center for Rehabilitation, University Medical Center Groningen, Groningen, The Netherlands, 4 Department of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands; email: ursina.arnet@paranet.ch, web: www.paranet.ch

Research paper thumbnail of Shoulder pain is associated with rate of rise and jerk of the applied forces during wheelchair propulsion in persons with paraplegic spinal cord injury

OBJECTIVE To investigate the association between propulsion biomechanics, including variables tha... more OBJECTIVE To investigate the association between propulsion biomechanics, including variables that describe smoothness of the applied forces, and shoulder pain in persons with SCI. DESIGN Cross-sectional, observational study. SETTING Non-university research institution. PARTICIPANTS 30 (age: 48.6±9.3 years, 83% males) community dwelling, wheelchair dependent participants with a chronic paraplegia between T2 and L1, with and without shoulder pain. INTERVENTIONS Not applicable MAIN OUTCOME MEASURE: Rate of rise and jerk of applied forces during wheelchair propulsion. Participants were stratified in low, moderate and high pain groups based on their Wheelchair User Shoulder Pain Index (WUSPI) score at the day of measurement. RESULTS A mixed-effect multilevel analysis showed that wheelchair users in the high pain group propelled with significantly greater rate of rise and jerk - measures that describe smoothness of the applied forces - as compared to persons with less or no pain, when co...

Research paper thumbnail of Change in mobility independence over 5 years for persons with chronic spinal cord injury

The Journal of Spinal Cord Medicine

OBJECTIVES To evaluate change in mobility independence (MI) in community dwelling persons with sp... more OBJECTIVES To evaluate change in mobility independence (MI) in community dwelling persons with spinal cord injury (SCI). PARTICIPANTS Community Survey. DESIGN Cohort study. Rasch analysis was applied to the mobility subscale of the Spinal Cord Independence Measure - Self-Report data from years 2012 to 2017, resulting in a Rasch Mobility Independence Score (RMIS). We employed multilevel modeling to examine RMIS and its change over 5 years, adjusting for demographics and SCI severity; random forest regression was applied to determine the impact of modifiable factors (e.g. environmental factors, home-support) on its change. RESULTS The analysis included 728 participants. The majority (≈85%) of participants demonstrated little or no change in RMIS from 2012 to 2017; however, a smaller proportion (15%) showed considerably large change of more than 10 on the 100-point scale. A mixed-effects model with random slopes and intercepts described the dataset very well (conditional R2 of 0.95) in terms of demographics and SCI severity. Age was the main predictor of change in RMIS. Considering SCI severity, change in RMIS was related to age for the subgroup with paraplegia, and to time since injury for the subgroup with tetraplegia. No impact of modifiable factors was found. CONCLUSION RMIS in persons with SCI changes over a period of 5 years, especially in elder patients with paraplegia and persons with incomplete tetraplegia with more than 15 years of time since injury. During routine follow-up change in mobility independence should be assessed in order to timely intervene and prevent mobility loss and participation limitations.

Research paper thumbnail of Biophysical aspects of handcycling performance in rehabilitation, daily life and recreational sports; a narrative review

Disability and Rehabilitation

Aim: In this narrative review the potential and importance of handcycling are evaluated. Four con... more Aim: In this narrative review the potential and importance of handcycling are evaluated. Four conceptual models form the framework for this review; (1) the International Classification of Functioning, Disability and Health; (2) the Stress-Strain-Capacity model; (3) the Human-Activity-Assistive Technology model; and (4) the power balance model for cyclic exercise. Methods: Based on international handcycle experience in (scientific) research and practice, evidencebased benefits of handcycling and optimization of handcycle settings are presented and discussed for rehabilitation, daily life and recreational sports. Results: As the load can be distributed over the full 360 cycle in handcycling, peak stresses in the shoulder joint and upper body muscles reduce. Moreover, by handcycling regularly, the physical capacity can be improved. The potential of handcycling as an exercise mode for a healthy lifestyle should be recognized and advocated much more widely in rehabilitation and adapted sports practice. The interface between handcycle and its user should be optimized by choosing a suitable person-specific handcycle, but mainly by optimizing the handcycle dimensions to one's needs and desires. These dimensions can influence efficient handcycle use and potentially improve both endurance and speed of handcycling. Conclusion: To optimize performance in rehabilitation, daily life and recreational sports, continued and more systematic research is required. ä IMPLICATIONS FOR REHABILITATION Handcycling allows users to travel farther distances at higher speeds and to train outdoors. It should be recognized as an alternative exercise modality for daily outdoor use, also already in early rehabilitation, while it contributes to a healthy lifestyle. To individualize handcycle performance, the user-handcycle (assistive device) interface as well as the vehicle mechanics should be optimized to minimize external power and reduce friction, so that the upper body capacity can be efficiently used. To optimize handcycling individual performance, both the physiological and biomechanical aspects of handcycling should be considered when monitoring or testing handcycle exercise.

Research paper thumbnail of Subacromial Space Reduction in Wheelchair Users: the Role of Loading and Subject Characteristics

Archives of Physical Medicine and Rehabilitation

Research paper thumbnail of Scapular kinematics during manual wheelchair propulsion in able-bodied participants

Clinical biomechanics (Bristol, Avon), 2018

Altered scapular kinematics have been associated with shoulder pain and functional limitations. T... more Altered scapular kinematics have been associated with shoulder pain and functional limitations. To understand kinematics in persons with spinal cord injury during manual handrim wheelchair propulsion, a description of normal scapular behaviour in able-bodied persons during this specific task is a prerequisite for accurate interpretation. The primary aim of this study is to describe scapular kinematics in able-bodied persons during manual wheelchair propulsion. Sixteen able-bodied, novice wheelchair users without shoulder complaints participated in the study. Kinematic and kinetic data were collected during a standardized pose in the anatomic posture, frontal-plane arm elevation and low-intensity steady-state handrim wheelchair propulsion and upper-body Euler angles were calculated. Scapulothoracic joint orientations in a static position were 36.7° (SD 5.4°), 6.4° (SD 9.1°) and 9.1° (SD 5.7°) for respectively protraction, lateral rotation and anterior tilt. At 80° of arm elevation in...

Research paper thumbnail of Shoulder pain in the Swiss spinal cord injury community: prevalence and associated factors

Disability and Rehabilitation

Abstract Purpose: To determine the prevalence of shoulder pain and to identify factors associated... more Abstract Purpose: To determine the prevalence of shoulder pain and to identify factors associated with shoulder pain in a nationwide survey of individuals living with spinal cord injury (SCI) in Switzerland. Methods: Data was collected through the 2012 community survey of the Swiss SCI Cohort Study (SwiSCI) (N = 1549; age 52.3 ± 14.8; 29% female). Sociodemographic and socioeconomic circumstances, SCI characteristics, health conditions as well as mobility independence and sporting activities were evaluated as predictor variables. Analyses were adjusted for item non-response (using multiple imputation) and unit-nonresponse (using inverse probability weighting). Results: The adjusted prevalence of shoulder pain was 35.8% (95% CI: 33.4–38.3). Multivariable regression analysis revealed higher odds of shoulder pain in females as compared to males (odds ratio: 1.89; 95% CI: 1.44–2.47), and when spasticity (1.36; 1.00–1.85) and contractures (2.47; 1.91–3.19) were apparent. Individuals with complete paraplegia (1.62; 1.13–2.32) or any tetraplegia (complete: 1.63; 1.01–2.62; incomplete: 1.82; 1.30–2.56) showed higher odds of shoulder pain compared to those with incomplete paraplegia. Conclusions: This survey revealed a high prevalence of shoulder pain. Sex, SCI severity, and specific health conditions were associated with having shoulder pain. Implications for rehabilitation Individuals with spinal cord injury have a high prevalence of shoulder pain. Females, individuals with complete paraplegia or any tetraplegia and individuals with contractures and spasticity should receive considerable attention in rehabilitation programmes due to their increased odds of having shoulder pain.

Research paper thumbnail of Chronic pain, depression and quality of life in individuals with spinal cord injury: Mediating role of participation

Journal of Rehabilitation Medicine

To test the hypotheses that: (i) pain is associated with depressive symptoms and quality of life;... more To test the hypotheses that: (i) pain is associated with depressive symptoms and quality of life; and (ii) participation restriction, satisfaction, and frequency mediate these relationships. Design: Population-based, cross-sectional study. Subjects/patients: Community-dwelling individuals with spinal cord injury (n = 1,549). Methods: Hypotheses were tested in individuals with at least moderate chronic pain on the spinal cord injury-Secondary Conditions Scale (n = 834), applying structural equation modelling to data for spinal cord injury subgroups related to lesion severity (paraplegia, tetraplegia, complete, incomplete) and time since injury (≤ 10 vs ≥ 10 years). Model parameters included pain intensity (numerical rating scale), participation frequency, restriction, satisfaction (Utrecht Scale of Evaluation of Rehabilitation-Participation; USER-Participation), depressive symptoms (5-item Mental Health Index of the Short Form Health Survey; MHI-5), and 5 selected quality of life items (World Health Organization Quality of Life Scale; WHOQoL-BREF). Results: Structural equation models confirmed associations of pain with depressive symptoms and quality of life, as well as the mediating role of participation restriction and low satisfaction with participation. These findings were apparent in individuals with tetraplegia or complete lesion and in those ≤ 10 years since paraplegia or incomplete injury. Conclusion: Unrestricted or satisfactory participation was found to be a crucial resource for individuals living less than 10 years with a more severe spinal cord injury, since it represents buffering potential for the negative effects of chronic pain on mental health and quality of life.

Research paper thumbnail of Availability and need of home adaptations for personal mobility among individuals with spinal cord injury

The Journal of Spinal Cord Medicine

Objective: To identify the availability and unmet need of home adaptations (HAs) among the Swiss ... more Objective: To identify the availability and unmet need of home adaptations (HAs) among the Swiss population with spinal cord injury (SCI). Design: Cross-sectional study. Setting: Swiss Spinal Cord Injury Community Survey 2012. Participants: Individuals aged 16 or older with chronic SCI living in Switzerland. Interventions: Not applicable. Outcome measures: The availability of ten HAs (self-report) was analyzed by sex, age, living situation, indoor mobility, SCI severity, SCI etiology and time since SCI. The unmet need (self-report of not having a HA but needing it) of HAs was analyzed by financial hardship. Results: Among the 482 study participants (mean age 55.2 years, standard deviation 15.0 years, 71.6% males), 85.1% had at least one HA. The most frequent HA was a wheelchair accessible shower (62.7%). Availability of HAs markedly varied with indoor mobility (e.g. 38.4% of participants using a wheelchair had a stair lift compared to 17.4% of those walking) and with SCI severity (e.g. 54.8% of those with complete paraplegia had a wheelchair accessible kitchen worktop compared to 26.0% of those with incomplete paraplegia). Unmet need was highest for adjustable kitchen worktops (78.7% of those with a need) and adjustable kitchen cabinets (75.7%) and lowest for wheelchair accessible showers (9.4%) and grab bars next to the toilet (8.5%). No significant differences in unmet need were found when stratifying for financial hardship. Conclusion: Availability of HAs is dependent on indoor mobility and SCI severity. There is a considerable degree of unmet need for selected HAs, which couldn't be explained by financial hardship.

Research paper thumbnail of Age-related variation in mobility independence among wheelchair users with spinal cord injury: A cross-sectional study

The journal of spinal cord medicine, 2015

Objective To evaluate age-related variation in mobility independence among community-living wheel... more Objective To evaluate age-related variation in mobility independence among community-living wheelchair users with spinal cord injury (SCI). Design Community Survey (2011-2013) as part of the Swiss Spinal Cord Injury Cohort Study. Setting Community. Participants Individuals aged 16 years or older with traumatic or non-traumatic SCI permanently residing in Switzerland and using a wheelchair for moving around moderate distances (10-100 m). Interventions Not applicable. Outcome Measures Mobility-related items of the Spinal Cord Independence Measure-Self Report were matched to the three principal domains 'changing basic body position', 'transferring oneself' and 'moving around'. Binary outcomes ('independence' vs. 'no independence') were created for every domain and analyzed using multivariable logistic regression (adjusted for sex, socioeconomic factors, SCI characteristics, and health conditions). Results Regression analyses (N = 949; 27% women; ...

Research paper thumbnail of Changes in supraspinatus and biceps tendon thickness: influence of fatiguing propulsion in wheelchair users with spinal cord injury

Spinal Cord

Study design A quasi-experimental, pretest-posttest design. Objectives To identify acute changes ... more Study design A quasi-experimental, pretest-posttest design. Objectives To identify acute changes in the supraspinatus and biceps tendon following fatiguing wheelchair propulsion and to associate tendon changes with risk factors associated with shoulder pain in persons with spinal cord injury (SCI). Setting Biomechanical laboratory Swiss Paraplegic Research. Methods A population-based sample of 50 wheelchair users with SCI at lesion level T2 or below participated. Fatigue was measured by using the rate of perceived exertion and heart rate. Linear regression techniques were used to assess the association between the dependent and independent variables. Dependent variables included absolute differences in supraspinatus and biceps tendon thickness, contrast, and echogenicity ratio assessed with ultrasound before and after a fatiguing wheelchair propulsion intervention. Independent variables included susceptibility to fatigue (Yes/No), the acromiohumeral distance, sex, time since injury, activity levels, and body weight. Results A reduction in supraspinatus tendon thickness after fatiguing wheelchair propulsion (-1.39 mm; 95% CI:-2.28;-0.51) was identified after controlling for all potential confounders. Females who fatigued (n = 4) displayed a greater reduction in supraspinatus tendon thickness as compared with those who did not fatigue (n = 7). In contrast, higher body weight was associated with an increase in supraspinatus tendon thickness and a greater acromio-humeral distance before the intervention was associated with an increase in biceps tendon thickness. Conclusions Acute changes in the supraspinatus and biceps tendon after fatiguing wheelchair propulsion may explain the high prevalence of tendon injuries in this population. Future research should determine the consequences of tendon changes and its relationship to tendinopathy.

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

Frontiers in Rehabilitation Sciences

ObjectiveThis study aimed to identify targets of intervention for reducing shoulder pain in wheel... more ObjectiveThis 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.MethodsFifty 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, supraspina...

Research paper thumbnail of Effect of fatiguing wheelchair propulsion on risk factors for shoulder pain in persons with spinal cord injury

<strong>Background:</strong> Shoulder pain is commonly reported within the spinal cor... more <strong>Background:</strong> Shoulder pain is commonly reported within the spinal cord injury (SCI) population and can have a detrimental impact on one's functioning, participation, and quality of life. Although wheel-chair propulsion is a highly inefficient mode of mobility and places the shoulder at risk for injury, it is one of the most important and most frequently used mobility devices. The mobile shoulder, compro-mised in mobility, relies on muscles and tendons to stabilise the joint. However, these muscles are prone to fatigue; how fatiguing propul-sion modifies biomechanics and muscular activation and relates to pathology and injury risk is poorly understood. <strong>Overall objective:</strong> To examine the effect of fatiguing wheelchair pro-pulsion on risk factors for shoulder pain in persons with SCI. The specific aims are threefold:1. To describe the prevalence of musculoskeletal shoulder pain and associated factors in the Swiss SCI population - Study 1 2. To define how fatiguing wheelchair propulsion changes biome-chanical and neuromuscular risk factors for shoulder pain in per-sons with SCI - Study 2 and Study 33. To evaluate how acute changes in tendon appearance with fa-tiguing wheelchair propulsion are associated with risk factors for shoulder pain in persons with SCI - Study 4. <strong>Methods: </strong>The first study used data from the Swiss SCI cohort study (SwiSCI) Community Survey database and investigated a large popu-lation based sample including persons with SCI living in Switzerland (n = 1549). The following quasi-experimental studies had a pre-test, post-test design, and examined the effect of fatiguing wheelchair pro-pulsion in wheelchair users with SCI via the implementation of an intervention of 15 minutes wheelchair propulsion including right and left turns, starts and stops, and rest periods. The second study defined how fatigue altered start-up propulsion biomechanics (n = 26). The third and fourth study were addressed with a SwiSCI nested project (n = 50). The third study defin [...]

Research paper thumbnail of Force application during handcycling and handrim wheelchair propulsion: an initial comparison

Journal of Applied Biomechanics, Jan 18, 2013

The aim of the study was to evaluate the external applied forces, the effectiveness of force appl... more The aim of the study was to evaluate the external applied forces, the effectiveness of force application and the net shoulder moments of handcycling in comparison with handrim wheelchair propulsion at different inclines. Ten able-bodied men performed standardized exercises on a treadmill at inclines of 1%, 2.5% and 4% with an instrumented handbike and wheelchair that measured three-dimensional propulsion forces. The results showed that during handcycling significantly lower mean forces were applied at inclines of 2.5% (P < .001) and 4% (P < .001) and significantly lower peak forces were applied at all inclines (1%: P = .014, 2.5% and 4%: P < .001). At the 2.5% incline, where power output was the same for both devices, total forces (mean over trial) of 22.8 N and 27.5 N and peak forces of 40.1 N and 106.9 N were measured for handbike and wheelchair propulsion. The force effectiveness did not differ between the devices (P = .757); however, the effectiveness did increase with ...

Research paper thumbnail of Shoulder Tendon Adaptations Following a Graded Exercise Test to Exhaustion in Highly Trained Wheelchair Rugby Athletes With Different Impairments

Frontiers in Rehabilitation Sciences

ObjectiveThis study aimed to identify acute changes in biceps and supraspinatus tendon characteri... more ObjectiveThis study aimed to identify acute changes in biceps and supraspinatus tendon characteristics before and after a graded exercise test to exhaustion (GXT) in highly trained wheelchair rugby (WR) athletes. A secondary aspect was to define chronic tendon adaptations related to the impairment of the athlete and the occupation of the tendon within the subacromial space (occupation ratio).MethodsTwelve WR athletes with different impairments (age = 32 ± 6 years; body mass = 67.2 ± 11.2 kg; 9.0 ± 3.6 years competing) volunteered for this study. Performance Corrected Wheelchair Users Shoulder Pain Index was used to quantify shoulder pain. Quantitative Ultrasound Protocols (QUS) were used to define supraspinatus and biceps tendon thickness, echogenicity, and echogenicity ratio of both dominant and non-dominant shoulder before and after the GXT including 22 ± 3.1 min submaximal propulsion and 10.2 ± 1.7 min maximal propulsion on a treadmill. Furthermore, the acromio-humeral distance (...

Research paper thumbnail of Handbiking: a biophysical analysis

Research paper thumbnail of Unilateral Shoulder Pain is Associated with Asymmetries in Tendon Thickness Following Maximum Exertion in an Elite Wheelchair Rugby Athlete: A Case in Point Towards Individualized Feedback

The purpose of this study was to describe changes in tendon thickness following maximum exertion ... more The purpose of this study was to describe changes in tendon thickness following maximum exertion in the symptomatic and asymptomatic shoulder of a highly trained wheelchair rugby athlete with tetraplegia. Tendon thickness of the biceps and supraspinatus on both sides were measured with ultrasound before any physical tests, after a treadmill test up to maximum exertion to define aerobic capacity, and after a 30s Wingate test to define anaerobic capacity. The athlete reported moderate to severe shoulder pain, quantified with the upper extremity pain symptom questionnaire (PSQ) on the left shoulder and no pain on the right shoulder. There was a meaningful reduction (i.e., > 2 x SD) in biceps and supraspinatus tendon thickness after the physical tests at the asymptomatic shoulder with no meaningful changes at the symptomatic shoulder. Reduction in tendon thickness has been related to increased alignment of the collagen fibres or creep which is a typical response to tensile loading. W...

Research paper thumbnail of Is Synchronous Handcycling Less Straining Than Handrim Wheelchair Propulsion ?

INTRODUCTION The upper extremities especially the shoulders are at serious risk for overuse in ha... more INTRODUCTION The upper extremities especially the shoulders are at serious risk for overuse in handrim wheelchair users. It has been shown that upper extremity complaints frequently occur within the wheelchair user population [1]. However, physical activity and an active lifestyle are important to maintain general fitness and to prevent long term health problems. Because handrim wheelchair propulsion has been shown to be an inefficient and mechanically straining form of ambulation [2], alternative propulsion mechanisms have been developed and studied. The handcycle has been proven to be an energetically more efficient and less straining alternative to the wheelchair [3]. However, the magnitude of the mechanical load of handcycling has not been subject of report. Due to the fact that the external power output needed for propulsion is produced with a considerably larger muscle mass, the mechanical load of handcycling on the upper extremity is believed to be lower.

Research paper thumbnail of MRI evaluation of shoulder pathologies in wheelchair users with spinal cord injury and the relation to shoulder pain

The journal of spinal cord medicine, 2021

OBJECTIVE To describe the number, specifics and co-occurrence of shoulder pathologies detected by... more OBJECTIVE To describe the number, specifics and co-occurrence of shoulder pathologies detected by MRI in manual wheelchair users with spinal cord injury and to evaluate the association between shoulder pathologies and presence of shoulder pain. DESIGN Cross-sectional observation study. SETTING Community. PARTICIPANTS Fifty-one wheelchair-dependent persons with spinal cord injury (44 males, 7 females, median age 50 years (IQR 14), median time since injury 24 years (IQR 16)) were allocated to pain or no-pain group based on the Wheelchair User Shoulder Pain Index. INTERVENTIONS Not applicable. OUTCOME MEASURES All persons underwent shoulder MRI. Pathologies were scored blinded by two experienced radiologists. Participant characteristics, number and severity of shoulder pathologies were analyzed descriptively. Logistic regression was performed to evaluate the association between MRI findings and shoulder pain. RESULTS The median number of co-occurring MRI findings per person ranged from...

Research paper thumbnail of Surgical Reconstruction of Intrinsic Muscle Function in Tetraplegia : Comparison of Techniques

The aim of this study was to analyze the contribution of the intrinsics (INT) to a functional han... more The aim of this study was to analyze the contribution of the intrinsics (INT) to a functional hand closing and to compare the results of two INT reconstruction techniques (ZancolliLasso and House procedures). Kinematics of cadaveric hands during hand closing (FDP tendon pulled by a motor) were analyzed at following conditions: no activation of INT, high activation of INT and reconstruction of INT by Zancolli-Lasso or House technique. The results showed that INT activation results in a more functional hand closing represented by a larger fingertip-topalm distance. Both reconstruction techniques showed improved grasp capacity in comparison to the nonreconstructed hand. However, only the House procedure restored hand kinematics resembling those of an active INT hand.

Research paper thumbnail of Shoulder Load in Handbike and Handrim Wheelchair Propulsion

1,2 Ursina Arnet, 1,2 Stefan van Drongelen, 3 Luc van der Woude and 2, 4 DirkJan Veeger 1 Swiss P... more 1,2 Ursina Arnet, 1,2 Stefan van Drongelen, 3 Luc van der Woude and 2, 4 DirkJan Veeger 1 Swiss Paraplegic Research, Nottwil, Switzerland, 2 Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands, 3 Center for Human Movement Sciences, Center for Rehabilitation, University Medical Center Groningen, Groningen, The Netherlands, 4 Department of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands; email: ursina.arnet@paranet.ch, web: www.paranet.ch

Research paper thumbnail of Shoulder pain is associated with rate of rise and jerk of the applied forces during wheelchair propulsion in persons with paraplegic spinal cord injury

OBJECTIVE To investigate the association between propulsion biomechanics, including variables tha... more OBJECTIVE To investigate the association between propulsion biomechanics, including variables that describe smoothness of the applied forces, and shoulder pain in persons with SCI. DESIGN Cross-sectional, observational study. SETTING Non-university research institution. PARTICIPANTS 30 (age: 48.6±9.3 years, 83% males) community dwelling, wheelchair dependent participants with a chronic paraplegia between T2 and L1, with and without shoulder pain. INTERVENTIONS Not applicable MAIN OUTCOME MEASURE: Rate of rise and jerk of applied forces during wheelchair propulsion. Participants were stratified in low, moderate and high pain groups based on their Wheelchair User Shoulder Pain Index (WUSPI) score at the day of measurement. RESULTS A mixed-effect multilevel analysis showed that wheelchair users in the high pain group propelled with significantly greater rate of rise and jerk - measures that describe smoothness of the applied forces - as compared to persons with less or no pain, when co...

Research paper thumbnail of Change in mobility independence over 5 years for persons with chronic spinal cord injury

The Journal of Spinal Cord Medicine

OBJECTIVES To evaluate change in mobility independence (MI) in community dwelling persons with sp... more OBJECTIVES To evaluate change in mobility independence (MI) in community dwelling persons with spinal cord injury (SCI). PARTICIPANTS Community Survey. DESIGN Cohort study. Rasch analysis was applied to the mobility subscale of the Spinal Cord Independence Measure - Self-Report data from years 2012 to 2017, resulting in a Rasch Mobility Independence Score (RMIS). We employed multilevel modeling to examine RMIS and its change over 5 years, adjusting for demographics and SCI severity; random forest regression was applied to determine the impact of modifiable factors (e.g. environmental factors, home-support) on its change. RESULTS The analysis included 728 participants. The majority (≈85%) of participants demonstrated little or no change in RMIS from 2012 to 2017; however, a smaller proportion (15%) showed considerably large change of more than 10 on the 100-point scale. A mixed-effects model with random slopes and intercepts described the dataset very well (conditional R2 of 0.95) in terms of demographics and SCI severity. Age was the main predictor of change in RMIS. Considering SCI severity, change in RMIS was related to age for the subgroup with paraplegia, and to time since injury for the subgroup with tetraplegia. No impact of modifiable factors was found. CONCLUSION RMIS in persons with SCI changes over a period of 5 years, especially in elder patients with paraplegia and persons with incomplete tetraplegia with more than 15 years of time since injury. During routine follow-up change in mobility independence should be assessed in order to timely intervene and prevent mobility loss and participation limitations.

Research paper thumbnail of Biophysical aspects of handcycling performance in rehabilitation, daily life and recreational sports; a narrative review

Disability and Rehabilitation

Aim: In this narrative review the potential and importance of handcycling are evaluated. Four con... more Aim: In this narrative review the potential and importance of handcycling are evaluated. Four conceptual models form the framework for this review; (1) the International Classification of Functioning, Disability and Health; (2) the Stress-Strain-Capacity model; (3) the Human-Activity-Assistive Technology model; and (4) the power balance model for cyclic exercise. Methods: Based on international handcycle experience in (scientific) research and practice, evidencebased benefits of handcycling and optimization of handcycle settings are presented and discussed for rehabilitation, daily life and recreational sports. Results: As the load can be distributed over the full 360 cycle in handcycling, peak stresses in the shoulder joint and upper body muscles reduce. Moreover, by handcycling regularly, the physical capacity can be improved. The potential of handcycling as an exercise mode for a healthy lifestyle should be recognized and advocated much more widely in rehabilitation and adapted sports practice. The interface between handcycle and its user should be optimized by choosing a suitable person-specific handcycle, but mainly by optimizing the handcycle dimensions to one's needs and desires. These dimensions can influence efficient handcycle use and potentially improve both endurance and speed of handcycling. Conclusion: To optimize performance in rehabilitation, daily life and recreational sports, continued and more systematic research is required. ä IMPLICATIONS FOR REHABILITATION Handcycling allows users to travel farther distances at higher speeds and to train outdoors. It should be recognized as an alternative exercise modality for daily outdoor use, also already in early rehabilitation, while it contributes to a healthy lifestyle. To individualize handcycle performance, the user-handcycle (assistive device) interface as well as the vehicle mechanics should be optimized to minimize external power and reduce friction, so that the upper body capacity can be efficiently used. To optimize handcycling individual performance, both the physiological and biomechanical aspects of handcycling should be considered when monitoring or testing handcycle exercise.

Research paper thumbnail of Subacromial Space Reduction in Wheelchair Users: the Role of Loading and Subject Characteristics

Archives of Physical Medicine and Rehabilitation

Research paper thumbnail of Scapular kinematics during manual wheelchair propulsion in able-bodied participants

Clinical biomechanics (Bristol, Avon), 2018

Altered scapular kinematics have been associated with shoulder pain and functional limitations. T... more Altered scapular kinematics have been associated with shoulder pain and functional limitations. To understand kinematics in persons with spinal cord injury during manual handrim wheelchair propulsion, a description of normal scapular behaviour in able-bodied persons during this specific task is a prerequisite for accurate interpretation. The primary aim of this study is to describe scapular kinematics in able-bodied persons during manual wheelchair propulsion. Sixteen able-bodied, novice wheelchair users without shoulder complaints participated in the study. Kinematic and kinetic data were collected during a standardized pose in the anatomic posture, frontal-plane arm elevation and low-intensity steady-state handrim wheelchair propulsion and upper-body Euler angles were calculated. Scapulothoracic joint orientations in a static position were 36.7° (SD 5.4°), 6.4° (SD 9.1°) and 9.1° (SD 5.7°) for respectively protraction, lateral rotation and anterior tilt. At 80° of arm elevation in...

Research paper thumbnail of Shoulder pain in the Swiss spinal cord injury community: prevalence and associated factors

Disability and Rehabilitation

Abstract Purpose: To determine the prevalence of shoulder pain and to identify factors associated... more Abstract Purpose: To determine the prevalence of shoulder pain and to identify factors associated with shoulder pain in a nationwide survey of individuals living with spinal cord injury (SCI) in Switzerland. Methods: Data was collected through the 2012 community survey of the Swiss SCI Cohort Study (SwiSCI) (N = 1549; age 52.3 ± 14.8; 29% female). Sociodemographic and socioeconomic circumstances, SCI characteristics, health conditions as well as mobility independence and sporting activities were evaluated as predictor variables. Analyses were adjusted for item non-response (using multiple imputation) and unit-nonresponse (using inverse probability weighting). Results: The adjusted prevalence of shoulder pain was 35.8% (95% CI: 33.4–38.3). Multivariable regression analysis revealed higher odds of shoulder pain in females as compared to males (odds ratio: 1.89; 95% CI: 1.44–2.47), and when spasticity (1.36; 1.00–1.85) and contractures (2.47; 1.91–3.19) were apparent. Individuals with complete paraplegia (1.62; 1.13–2.32) or any tetraplegia (complete: 1.63; 1.01–2.62; incomplete: 1.82; 1.30–2.56) showed higher odds of shoulder pain compared to those with incomplete paraplegia. Conclusions: This survey revealed a high prevalence of shoulder pain. Sex, SCI severity, and specific health conditions were associated with having shoulder pain. Implications for rehabilitation Individuals with spinal cord injury have a high prevalence of shoulder pain. Females, individuals with complete paraplegia or any tetraplegia and individuals with contractures and spasticity should receive considerable attention in rehabilitation programmes due to their increased odds of having shoulder pain.

Research paper thumbnail of Chronic pain, depression and quality of life in individuals with spinal cord injury: Mediating role of participation

Journal of Rehabilitation Medicine

To test the hypotheses that: (i) pain is associated with depressive symptoms and quality of life;... more To test the hypotheses that: (i) pain is associated with depressive symptoms and quality of life; and (ii) participation restriction, satisfaction, and frequency mediate these relationships. Design: Population-based, cross-sectional study. Subjects/patients: Community-dwelling individuals with spinal cord injury (n = 1,549). Methods: Hypotheses were tested in individuals with at least moderate chronic pain on the spinal cord injury-Secondary Conditions Scale (n = 834), applying structural equation modelling to data for spinal cord injury subgroups related to lesion severity (paraplegia, tetraplegia, complete, incomplete) and time since injury (≤ 10 vs ≥ 10 years). Model parameters included pain intensity (numerical rating scale), participation frequency, restriction, satisfaction (Utrecht Scale of Evaluation of Rehabilitation-Participation; USER-Participation), depressive symptoms (5-item Mental Health Index of the Short Form Health Survey; MHI-5), and 5 selected quality of life items (World Health Organization Quality of Life Scale; WHOQoL-BREF). Results: Structural equation models confirmed associations of pain with depressive symptoms and quality of life, as well as the mediating role of participation restriction and low satisfaction with participation. These findings were apparent in individuals with tetraplegia or complete lesion and in those ≤ 10 years since paraplegia or incomplete injury. Conclusion: Unrestricted or satisfactory participation was found to be a crucial resource for individuals living less than 10 years with a more severe spinal cord injury, since it represents buffering potential for the negative effects of chronic pain on mental health and quality of life.

Research paper thumbnail of Availability and need of home adaptations for personal mobility among individuals with spinal cord injury

The Journal of Spinal Cord Medicine

Objective: To identify the availability and unmet need of home adaptations (HAs) among the Swiss ... more Objective: To identify the availability and unmet need of home adaptations (HAs) among the Swiss population with spinal cord injury (SCI). Design: Cross-sectional study. Setting: Swiss Spinal Cord Injury Community Survey 2012. Participants: Individuals aged 16 or older with chronic SCI living in Switzerland. Interventions: Not applicable. Outcome measures: The availability of ten HAs (self-report) was analyzed by sex, age, living situation, indoor mobility, SCI severity, SCI etiology and time since SCI. The unmet need (self-report of not having a HA but needing it) of HAs was analyzed by financial hardship. Results: Among the 482 study participants (mean age 55.2 years, standard deviation 15.0 years, 71.6% males), 85.1% had at least one HA. The most frequent HA was a wheelchair accessible shower (62.7%). Availability of HAs markedly varied with indoor mobility (e.g. 38.4% of participants using a wheelchair had a stair lift compared to 17.4% of those walking) and with SCI severity (e.g. 54.8% of those with complete paraplegia had a wheelchair accessible kitchen worktop compared to 26.0% of those with incomplete paraplegia). Unmet need was highest for adjustable kitchen worktops (78.7% of those with a need) and adjustable kitchen cabinets (75.7%) and lowest for wheelchair accessible showers (9.4%) and grab bars next to the toilet (8.5%). No significant differences in unmet need were found when stratifying for financial hardship. Conclusion: Availability of HAs is dependent on indoor mobility and SCI severity. There is a considerable degree of unmet need for selected HAs, which couldn't be explained by financial hardship.

Research paper thumbnail of Age-related variation in mobility independence among wheelchair users with spinal cord injury: A cross-sectional study

The journal of spinal cord medicine, 2015

Objective To evaluate age-related variation in mobility independence among community-living wheel... more Objective To evaluate age-related variation in mobility independence among community-living wheelchair users with spinal cord injury (SCI). Design Community Survey (2011-2013) as part of the Swiss Spinal Cord Injury Cohort Study. Setting Community. Participants Individuals aged 16 years or older with traumatic or non-traumatic SCI permanently residing in Switzerland and using a wheelchair for moving around moderate distances (10-100 m). Interventions Not applicable. Outcome Measures Mobility-related items of the Spinal Cord Independence Measure-Self Report were matched to the three principal domains 'changing basic body position', 'transferring oneself' and 'moving around'. Binary outcomes ('independence' vs. 'no independence') were created for every domain and analyzed using multivariable logistic regression (adjusted for sex, socioeconomic factors, SCI characteristics, and health conditions). Results Regression analyses (N = 949; 27% women; ...

Research paper thumbnail of Changes in supraspinatus and biceps tendon thickness: influence of fatiguing propulsion in wheelchair users with spinal cord injury

Spinal Cord

Study design A quasi-experimental, pretest-posttest design. Objectives To identify acute changes ... more Study design A quasi-experimental, pretest-posttest design. Objectives To identify acute changes in the supraspinatus and biceps tendon following fatiguing wheelchair propulsion and to associate tendon changes with risk factors associated with shoulder pain in persons with spinal cord injury (SCI). Setting Biomechanical laboratory Swiss Paraplegic Research. Methods A population-based sample of 50 wheelchair users with SCI at lesion level T2 or below participated. Fatigue was measured by using the rate of perceived exertion and heart rate. Linear regression techniques were used to assess the association between the dependent and independent variables. Dependent variables included absolute differences in supraspinatus and biceps tendon thickness, contrast, and echogenicity ratio assessed with ultrasound before and after a fatiguing wheelchair propulsion intervention. Independent variables included susceptibility to fatigue (Yes/No), the acromiohumeral distance, sex, time since injury, activity levels, and body weight. Results A reduction in supraspinatus tendon thickness after fatiguing wheelchair propulsion (-1.39 mm; 95% CI:-2.28;-0.51) was identified after controlling for all potential confounders. Females who fatigued (n = 4) displayed a greater reduction in supraspinatus tendon thickness as compared with those who did not fatigue (n = 7). In contrast, higher body weight was associated with an increase in supraspinatus tendon thickness and a greater acromio-humeral distance before the intervention was associated with an increase in biceps tendon thickness. Conclusions Acute changes in the supraspinatus and biceps tendon after fatiguing wheelchair propulsion may explain the high prevalence of tendon injuries in this population. Future research should determine the consequences of tendon changes and its relationship to tendinopathy.