Investigation of Factors Associated With Manual Wheelchair Mobility in Persons With Spinal Cord Injury

Patient Satisfaction with Occupational Therapy Services for Wheeled Mobility and Seating Devices

Satisfaction of 81 patients was evaluated before and after receiving occupational therapy services. There was a statistically significant difference between patients' scores before and after receiving occupational therapy services (p < .05). Over 85% indicated a high satisfaction in relation to quality and health outcomes attributed to occupational therapy services, 44% reported barriers related to limited availability, accessibility, and knowledge of occupational therapy services, and 35% made suggestions for improvements. Patient-therapist communication and easy access to occupational therapy services can enhance occupational therapy knowledge, lead to positive patient experience and quality health outcomes, and higher patient satisfaction.

Effects of wheels and tires on high-strength lightweight wheelchair propulsion cost using a robotic wheelchair tester

PURPOSE

This study was designed to investigate the effect of wheel and tire selections on the propulsion characteristics of a high-strength lightweight manual wheelchair using robotic wheelchair propulsion.

MATERIALS AND METHODS

Four configurations were compared with differing combinations of drive wheel tires and casters, with the baseline reflecting the manufacturer configuration of a solid mag drive wheel and 8"×1" caster. The robotic wheelchair tester propelled the chair using pre-generated straight and curvilinear manoeuvres using repeatable and reliable cyclic torque profiles. Additionally, energy loss of the components was measured using coast-down deceleration tests to approximate the system-level rolling resistance of each configuration.

RESULTS

Results indicate a significant decrease in propulsion cost, increased distance travelled and increased manoeuvrability across all configurations, with upgraded casters and tires.

CONCLUSIONS

These results indicated that with better casters and drive wheel tires, the performance of high strength lightweight wheelchairs can be improved and better meet the mobility needs of users.Implications for rehabilitationWheel and tire selection can have a demonstrable impact on the propulsion efficiency of manual wheelchairsCoast-down test protocols can be used as a simple and cost-effective means of assessing representative energy losses across various surfacesWheelchair configurations can be optimized with proper knowledge of the main energetic loss contributions and the environments and contexts of use.

Usability of a virtual reality manual wheelchair simulator

PURPOSE

Individuals with impaired mobility often require assistance for getting around. The skilled use of a manual wheelchair (MW) is required in order to gain independence while preventing injuries. Training in a virtual reality (VR) setting allows for safe practice of MW skills in a wide range of environments. We developed a low-cost MW simulator which includes visual and haptic feedback. Our objectives were to assess the usability and fidelity of the VR simulator, by clinicians and expert MW users, and to determine whether the addition of haptic feedback would positively improve the user's experience.

MATERIALS AND METHODS

This mixed method study investigated the sense of presence, overall experience and ease of use of the experience in six MW users, as well as five clinicians (wheeled mobility experts) who practiced in the simulator.

RESULTS

Participants reported a positive perception of usefulness, sense of presence, and immersion during the MiWe simulator experience. The addition of haptic feedback to the simulator significantly enhanced fidelity of the overall experience, compared to the no-feedback condition.

CONCLUSION

Our low-cost simulator was well perceived by clinicians and MW users and was considered as a potentially useful tool to complement MW skill training.IMPLICATIONS FOR REHABILITATIONWe developed a low-cost, virtual reality simulator with visual and haptic feedback, for the practice of manual wheelchair skills.Expert clinicians and wheelchair users reported a positive experience after practicing in the wheelchair simulator, in terms of presence, realism and usability.Participants highlighted the potential usefulness of our low-cost simulator in the training of manual wheelchair skills.

Predictors of participation enfranchisement of wheelchair users with spinal cord injury in the United States

CONTEXT/OBJECTIVE

To investigate predictors of participation enfranchisement of individuals living with spinal cord injury (SCI) who use a wheelchair full-time.

DESIGN

Secondary data analysis of a cross-sectional study.

SETTING

Community, United States.

PARTICIPANTS

Participants were 59 wheelchair users (median age of 52.5 years, IQR = 21) with chronic SCI (>1 year after injury).

INTERVENTIONS

No intervention.

MAIN OUTCOME MEASURES

Participation enfranchisement was measured using the enfranchisement scale of the Community Participation Indicators (CPI). Dependent variables included importance of participation (CPI-Importance) and control over participation (CPI-Control) subscales of the CPI. Independent variables included demographics and clinical characteristics (age, sex, time since injury, level of injury), wheelchair skills, mobility level, symptoms of depression, and environmental barriers. Backward multivariable linear regression analyses were carried-out to identify predictors of CPI-Importance and CPI-Control.

RESULTS

Five predictors including mobility level, wheelchair skills, sex, level of injury, and symptoms of depression explained 57% (F = 14; P < 0.01) of the variance in CPI-Importance. Three predictors including mobility level, symptoms of depression, and environmental barriers explained 60% (F = 27; P < 0.01) of the variance in CPI-Control.

CONCLUSION

This study provides evidence of potential modifiable factors such as mobility, wheelchair skills, environmental barriers, and symptoms of depression that can influence importance of participation and control over participation of wheelchair users with SCI. The models presented in this study can serve as a conceptual framework to design effective interventions to improve participation enfranchisement of wheelchair users with SCI.

Wheeled and Seated Mobility Devices Provision: Quantitative Findings and SWOT Thematic Analysis of a Global Occupational Therapist Survey

PURPOSE

To better understand the global role of occupational therapists and explore facilitators and barriers impacting user access to high quality, affordable wheeled and seated mobility device (WSMD) provision worldwide.

METHODS

Mixed-method approach utilizing quantitative findings and qualitative strengths, weaknesses, opportunities, and threats (SWOT) analysis of a global online survey.

RESULTS

A total of 696 occupational therapists from 61 countries completed the survey. Almost 49% had 10 or more years of experience with the provision of WSMDs. WSMD provision had positive, significant associations with attainment of certification (0.000), higher service funding (0.000), higher country income (0.001), standardized training (0.003), continuous professional development (0.004), higher experience (0.004), higher user satisfaction (0.032), custom-made device provision (0.038), higher staff capacity (0.040), and more time working with users (0.050); negative, significant associations were identified with high cost of WSMDs (0.006) and pre-made device provision (0.019). SWOT analysis identified high country income, funding, experience, training, certification from global partners, variety of roles and practice settings, and interdisciplinary teamwork as strengths and opportunities for professional growth, while low country income, lack of time/staff capacity/standardization/support services, and poor access to proper devices were indicated as weaknesses and threats.

CONCLUSION

Occupational therapists are skilled healthcare professionals and provide a variety of WSMD services. Efforts to build collaborative partnerships, enhance access to occupational therapists and funding options, improve service and standards for WMSD service delivery, and promote professional development will help to overcome challenges and facilitate WSMD provision globally. Promoting practices based on best available evidence for WSMD provision worldwide should be prioritized.

Turning in Circles: Understanding Manual Wheelchair Use Towards Developing User-Friendly Steering Systems

For people with physical disabilities, manual wheelchairs are essential enablers of mobility, participation in society, and a healthy lifestyle. Their most general design offers great flexibility and direct feedback, but has been described to be inefficient and demands good coordination of the upper extremities while critically influencing users’ actions. Multiple research groups have used Inertial Measurement Units (IMUs) to quantify physical activities in wheelchairs arguing that knowledge over behavioural patterns in manual wheelchair usage can guide technological development and improved designs. The present study investigates turning behaviour among fulltime wheelchair users, laying the foundation of the development of novel steering systems that allow directing kinetic energy by means other than braking. Three wearable sensors were installed on the wheelchairs of 14 individuals for tracking movement over an entire week. During detected “moving windows”, phases where the velocities of the two rear wheels differed by more than 0.05 m/s were considered as turns. Kinematic characteristics for both turns-on-the-spot as well as for moving turns were then derived from the previously reconstructed wheeled path. For the grand total of 334 km of recorded wheelchair movement, a turn was detected every 3.6 m, which equates to about 900 turns per day on average and shows that changing and adjusting direction is fundamental in wheelchair practice. For moving turns, a median turning radius of 1.09 m and a median turning angle of 39° were found. With a median of 89°, typical turning angles were considerably larger for turns-on-the-spot, which accounted for roughly a quarter of the recognised turns and often started from a standstill. These results suggest that a frequent pattern in daily wheelchair usage is to initiate movement with an orienting turn-on-the-spot, and cover distances with short, straightforward sections while adjusting direction in small and tight moving turns. As large bends often require simultaneous pushing and breaking, this is, perhaps, the result of users intuitively optimising energy efficiency, but more research is needed to understand how the design of the assistive devices implicitly directs users’ movement.

Estimation of manual wheelchair-based activities in the free-living environment using a neural network model with inertial body-worn sensors

Shoulder pain is common in manual wheelchair (MWC) users. Overuse is thought to be a major cause, but little is known about exposure to activities of daily living (ADLs). The study goal was to develop a method to estimate three conditions in the field: (1) non-propulsion activity, (2) MWC propulsion, and (3) static time using an inertial measurement unit (IMU). Upper arm IMU data were collected as ten MWC users performed lab-based MWC-related ADLs. A neural network model was developed to classify data as non-propulsion activity, propulsion, or static, and validated for the lab-based data collection by video comparison. Six of the participants' free-living IMU data were collected and the lab-based model was applied to estimate daily non-propulsion activity, propulsion, and static time. The neural network model yielded lab-based validity measures ≥0.87 for differentiating non-propulsion activity, propulsion, and static time. A quasi-validation of one participant's field-based data yielded validity measures ≥0.66 for identifying propulsion. Participants' estimated mean daily non-propulsion activity, propulsion, and static time ranged from 158 to 409, 13 to 25, and 367 to 609 min, respectively. The preliminary results suggest the model may be able to accurately identify MWC users' field-based activities. The inclusion of field-based IMU data in the model could further improve field-based classification.

Effects of a trained mobility assistance dog on upper extremity muscular effort during wheelchair propulsion on tiled and carpeted floors in individuals with a spinal cord injury

BACKGROUND

Many manual wheelchair users with a spinal cord injury are at risk of developing secondary upper extremity musculoskeletal impairments. The use of a mobility assistance dog may represent a way to mitigate this risk. This study aims to compare upper extremity muscular effort in this population when propelling a manual wheelchair on tiled and carpeted surfaces with and without the assistance of a dog.

METHOD

Thirteen adults with a spinal cord injury propelled their manual wheelchairs at a self-selected natural speed over a 10-meter distance on tiled abrasive and carpeted floors with and without their mobility assistance dog. Surface electromyography of the pectoralis major, anterior deltoid, biceps, and triceps was recorded and normalized against its maximal value extracted from maximal voluntary contractions. Time needed to perform each task was also computed.

FINDINGS

The forward pull provided by the dog significantly and meaningfully reduced the muscular effort when propelling on the tiled floor and, even more so, on carpeted surfaces for the pectoralis major (-27.0% and -59.2%), the anterior deltoid (-54.8% and -92.4%), the biceps (-53.9% and -57.6%), and the triceps (-45.7% and -67.3%). The time needed to travel the 10-meter distance was also significantly and meaningfully reduced on the tiled and carpeted surfaces (-21.9% and -30.3%, respectively).

INTERPRETATION

The provision of a mobility assistance dog represents a viable rehabilitation alternative to minimizing upper extremity muscular effort while also optimizing speed during propulsion in manual wheelchair users with a spinal cord injury.

Estimation of Energy Expenditure in Wheelchair-Bound Spinal Cord Injured Individuals Using Inertial Measurement Units

A healthy lifestyle reduces the risk of cardio-vascular disease. As wheelchair-bound individuals with spinal cord injury (SCI) are challenged in their activities, promoting and coaching an active lifestyle is especially relevant. Although there are many commercial activity trackers available for the able-bodied population, including those providing feedback about energy expenditure (EE), activity trackers for the SCI population are largely lacking, or are limited to a small set of activities performed in controlled settings. The aims of the present study were to develop and validate an algorithm based on inertial measurement unit (IMU) data to continuously monitor EE in wheelchair-bound individuals with a SCI, and to establish reference activity values for a healthy lifestyle in this population. For this purpose, EE was measured in 30 subjects each wearing four IMUs during 12 different physical activities, randomly selected from a list of 24 activities of daily living. The proposed algorithm consists of three parts: resting EE estimation based on multi-linear regression, an activity classification using a k-nearest-neighbors algorithm, and EE estimation based on artificial neural networks (ANNs). The mean absolute estimation error for the ANN-based algorithm was 14.4% compared to indirect calorimeter measurements. Based on reference values from the literature and the data collected within this study, we recommend wheeling 3 km per day for a healthy lifestyle in wheelchair-bound SCI individuals. Combining the proposed algorithm with a recommendation for physical activity provides a powerful tool for the promotion of an active lifestyle in the SCI population, thereby reducing the risk for secondary diseases.

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

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

Effect of tendon vibration during wide-pulse neuromuscular electrical stimulation (NMES) on muscle force production in people with spinal cord injury (SCI)

Background

Neuromuscular electrical stimulation (NMES) is commonly used in skeletal muscles in people with spinal cord injury (SCI) with the aim of increasing muscle recruitment and thus muscle force production. NMES has been conventionally used in clinical practice as functional electrical stimulation (FES), using low levels of evoked force that cannot optimally stimulate muscular strength and mass improvements, and thus trigger musculoskeletal changes in paralysed muscles. The use of high intensity intermittent NMES training using wide-pulse width and moderate-intensity as a strength training tool could be a promising method to increase muscle force production in people with SCI. However, this type of protocol has not been clinically adopted because it may generate rapid muscle fatigue and thus prevent the performance of repeated high-intensity muscular contractions in paralysed muscles. Moreover, superimposing patellar tendon vibration onto the wide-pulse width NMES has been shown to elicit further increases in impulse or, at least, reduce the rate of fatigue in repeated contractions in able-bodied populations, but there is a lack of evidence to support this argument in people with SCI.

Methods

Nine people with SCI received two NMES protocols with and without superimposing patellar tendon vibration on different days (i.e. STIM and STIM+vib), which consisted of repeated 30 Hz trains of 58 wide-pulse width (1000 μs) symmetric biphasic pulses (0.033-s inter-pulse interval; 2 s stimulation train; 2-s inter-train interval) being delivered to the dominant quadriceps femoris. Starting torque was 20% of maximal doublet-twitch torque and stimulations continued until torque declined to 50% of the starting torque. Total knee extensor impulse was calculated as the primary outcome variable.

Results

Total knee extensor impulse increased in four subjects when patellar tendon vibration was imposed (59.2 ± 15.8%) but decreased in five subjects (− 31.3 ± 25.7%). However, there were no statistically significant differences between these sub-groups or between conditions when the data were pooled.

Conclusions

Based on the present results there is insufficient evidence to conclude that patellar tendon vibration provides a clear benefit to muscle force production or delays muscle fatigue during wide-pulse width, moderate-intensity NMES in people with SCI.

Trial registration

ACTRN12618000022268. Date: 11/01/2018. Retrospectively registered.

Characterizing the community use of an ultralight wheelchair with "on the fly" adjustable seating functions: A pilot study

An ultralight manual wheelchair that allows users to independently adjust rear seat height and backrest angle during normal everyday usage was recently commercialized. Prior research has been performed on wheelchair tilt, recline, and seat elevation use in the community, however no such research has been done on this new class of manual ultralight wheelchair with "on the fly" adjustments. The objective of this pilot study was to investigate and characterize the use of the two adjustable seating functions available on the Elevation™ ultralight dynamic wheelchair during its use in the community. Eight participants had data loggers installed onto their own wheelchair for seven days to measure rear seat height, backrest angle position, occupied sitting time, and distance traveled. Analysis of rear seat height and backrest adjustment data revealed considerable variability in the frequency of use and positions used by participants. There was a wide spread of mean daily rear seat heights among participants, from 34.1 cm to 46.7 cm. Two sub-groups of users were further identified: those who sat habitually at a single typical rear seat height, and those who varied their rear seat height more continuously. Findings also showed that participants used the rear seat height adjustment feature significantly more often than the backrest adjustment feature. This obvious contrast in feature use may indicate that new users of this class of wheelchair may benefit from specific training. While the small sample size and exploratory nature of this study limit the generalizability of our results, our findings offer a first look at how active wheelchairs users are using a new class of ultralight wheelchair with "on the fly" seating adjustments in their communities. Further studies are recommended to better understand the impact of dynamic seating and positioning on activity, participation and quality of life.

Objective and Self-Reported Physical Activity Measures and Their Association With Depression and Satisfaction With Life in Persons With Spinal Cord Injury

OBJECTIVE

To identify associations between objective and self-reported measures of physical activity (PA) and relationships with depression and satisfaction with life (SWL) in persons with spinal cord injury (SCI).

DESIGN

Retrospective, cross-sectional study of objectively measured wheelchair propulsion (WCP) from 2 studies in which an odometer was attached to participants' wheelchairs to record daily speed and distance. Self-reported data were collected in a separate study examining dyspnea, PA, mood, and SWL.

SETTING

Outpatient clinic in a rehabilitation center.

PARTICIPANTS

Individuals (N=86) with traumatic SCI who use a manual wheelchair.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Objective measures of PA included average daily distance and speed of WCP measured by an odometer. Self-report questionnaires included demographics, the 24-hour recall of transfers, Physical Activity Recall Assessment for People with SCI, the Patient Health Questionnaire-2 (PHQ-2) to document depressive symptoms, and the Satisfaction With Life Scale (SWLS).

RESULTS

Both objective measures of WCP, average daily distance and speed, were predicted by the combination of self-reported daily time away from home/yard and lower frequency of car transfers ([r=.367, P=.002] and [r=.434, P<.001], respectively). Daily distance of WCP was negatively correlated with depression (PHQ-2) (r=-.309, P=.004). Time in leisure PA was the only significant predictor of SWLS scores (r=.321, P=.003).

CONCLUSIONS

Short-term recall of hours away from home/yard not spent driving or riding in a vehicle is suggested as a self-report measure that is moderately related to overall WCP PA in this population. Results of this study suggest that depression is related to decreased PA and WCP activity, while SWL is related to leisure PA.

Wheelchair use in ultra-lightweight wheelchair users

PURPOSE

The goal of this study was to describe how ultra-lightweight wheelchair users use their wheelchairs during everyday mobility.

METHOD

We instrumented a convenience sample of 69 ultra-lightweight wheelchair users with a seat switch to measure their occupancy, and an accelerometer on their wheel to measure distance wheeled, time spent wheeling and daily bouts of mobility.

RESULTS

On the median day, subjects wheeled 83 bouts and 1.4 km over 45 min. A typical bout of mobility was 8.3 m in length, lasting 20 s and occurring at a speed of 0.44 m/s. Fast (>1 m/s) and long (>2 min) bouts represented less than 4% of bouts and were more common among younger participants and those who were employed or a student.

CONCLUSIONS

Highly functional manual wheelchair users present with a significant mobility disability, moving far less than their ambulating peers despite moving with similar mobility characteristics. The typical bout characteristics - short and slow bouts - are consistent with indoor mobility and transitions between functional activities. For wheelchair users, it highlights the importance of manoeuverability and the need for prescription and training to emphasize manoeuverability. Implications for Rehabilitation Measurement of wheelchair use, both how and how much, might provide unique insight to what equipment would be most appropriate for an individual. Participants who used an ultralight wheelchair presented with a significant mobility disability, wheeling only 1.7 km/day on average. Fast (>1 m/s) and long (>2 min) bouts are uncommon, representing less than 4% of bouts. Younger participants and those who were employed or a student were more likely to wheel one fast and long bout per day. Because wheelchair mobility was dominated by short, slow bouts, prescription and training need to emphasize maneuverability.

Shoulder Strength and Physical Activity Predictors of Shoulder Pain in People With Paraplegia From Spinal Injury: Prospective Cohort Study

BACKGROUND

Shoulder joint pain is a frequent secondary complaint for people following spinal cord injury (SCI).

OBJECTIVE

The purpose of this study was to determine predictors of shoulder joint pain in people with paraplegia.

METHODS/DESIGN

A 3-year longitudinal study was conducted. Participants were people with paraplegia who used a manual wheelchair for at least 50% of their mobility and were asymptomatic for shoulder pain at study entry. Participants were classified as having developed shoulder pain if they experienced an increase of ≥10 points on the Wheelchair User's Shoulder Pain Index in the 3-year follow-up period. Measurements of maximal isometric shoulder torques were collected at study entry (baseline), 18 months, and 3 years. Daily activity was measured using a wheelchair odometer, and self-reported daily transfer and raise frequency data were collected by telephone every 6 weeks.

RESULTS

Two hundred twenty-three participants were enrolled in the study; 39.8% developed shoulder pain over the 3-year follow-up period. Demographic variables and higher activity levels were not associated with shoulder pain onset. Baseline maximal isometric torque (normalized by body weight) in all shoulder muscle groups was 10% to 15% lower in participants who developed shoulder pain compared with those who remained pain-free. Lower shoulder adduction torque was a significant predictor of shoulder pain development (log-likelihood test=11.38), but the model explained only 7.5% of shoulder pain onset and consequently is of limited clinical utility.

LIMITATIONS

Time since SCI varied widely among participants, and transfer and raise activity was measured by participant recall.

CONCLUSIONS

Participants who developed shoulder pain had decreased muscle strength, particularly in the shoulder adductors, and lower levels of physical activity prior to the onset of shoulder pain. Neither factor was a strong predictor of shoulder pain onset.

A review of factors influencing participation in social and community activities for wheelchair users

OBJECTIVE

To systematically identify factors associated with participation in social and community activities for adult wheelchair users (WCUs).

DATA SOURCES

PubMed/MEDLINE, CINAHL, PsycINFO and EMBASE.

STUDY SELECTION

Quantitative and qualitative peer-reviewed publications were included, which were written in English, reported original research and investigated factors associated with social and community participation in adult WCUs.

DATA EXTRACTION

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used. Factors were organized using the International Classification of Functioning, Disability and Health (ICF).

DATA SYNTHESIS

Thirty-five studies were selected: two of power WCUs, 10 of manual WCUs and 23 of both. Six qualitative studies, ranging in quality from 8/10 to 9/10 and 29 quantitative studies were included, ranging in quality from 4/15 to 11/15. Fifteen body function, 4 activity, 5 participation, 15 environmental and 14 personal factors were found to be associated with social and community participation.

CONCLUSIONS

Social and community participation of WCUs is associated with factors from all ICF domains. Wheelchair factors, accessibility, skills with wheelchair use, pain, finances and education are modifiable factors frequently reported to be associated with participation. Experimental research focusing on modifiable factors is needed to further our understanding of factors influencing participation among WCUs. Implications for Rehabilitation Wheelchair factors, including comfort and durability, are associated with participation and may be targeted in clinical intervention. Wheelchair skills are clinically modifiable and have been shown to improve participation in manual wheelchair users. Body functions (e.g. confidence, depression and fatigue) and personal factors (e.g. finances and level of education) may be considered for clinical intervention.

Development and evaluation of a gyroscope-based wheel rotation monitor for manual wheelchair users

OBJECTIVE

To develop and evaluate a wireless gyroscope-based wheel rotation monitor (G-WRM) that can estimate speeds and distances traveled by wheelchair users during regular wheelchair propulsion as well as wheelchair sports such as handcycling, and provide users with real-time feedback through a smartphone application.

METHODS

The speeds and the distances estimated by the G-WRM were compared with the criterion measures by calculating absolute difference, mean difference, and percentage errors during a series of laboratory-based tests. Intraclass correlations (ICC) and the Bland-Altman plots were also used to assess the agreements between the G-WRM and the criterion measures. In addition, battery life and wireless data transmission tests under a number of usage conditions were performed.

RESULTS

The percentage errors for the angular velocities, speeds, and distances obtained from three prototype G-WRMs were less than 3% for all the test trials. The high ICC values (ICC (3,1) > 0.94) and the Bland-Altman plots indicate excellent agreement between the estimated speeds and distances by the G-WRMs and the criterion measures. The battery life tests showed that the device could last for 35 hours in wireless mode and 139 hours in secure digital card mode. The wireless data transmission tests indicated less than 0.3% of data loss.

CONCLUSION

The results indicate that the G-WRM is an appropriate tool for tracking a spectrum of wheelchair-related activities from regular wheelchair propulsion to wheelchair sports such as handcycling. The real-time feedback provided by the G-WRM can help wheelchair users self-monitor their everyday activities.

Criterion validity and accuracy of global positioning satellite and data logging devices for wheelchair tennis court movement

PURPOSE

To compare the criterion validity and accuracy of a 1 Hz non-differential global positioning system (GPS) and data logger device (DL) for the measurement of wheelchair tennis court movement variables.

METHODS

Initial validation of the DL device was performed. GPS and DL were fitted to the wheelchair and used to record distance (m) and speed (m/second) during (a) tennis field (b) linear track, and (c) match-play test scenarios. Fifteen participants were monitored at the Wheelchair British Tennis Open.

RESULTS

Data logging validation showed underestimations for distance in right (DLR) and left (DLL) logging devices at speeds >2.5 m/second. In tennis-field tests, GPS underestimated distance in five drills. DLL was lower than both (a) criterion and (b) DLR in drills moving forward. Reversing drill direction showed that DLR was lower than (a) criterion and (b) DLL. GPS values for distance and average speed for match play were significantly lower than equivalent values obtained by DL (distance: 2816 (844) vs. 3952 (1109) m, P = 0.0001; average speed: 0.7 (0.2) vs. 1.0 (0.2) m/second, P = 0.0001). Higher peak speeds were observed in DL (3.4 (0.4) vs. 3.1 (0.5) m/second, P = 0.004) during tennis match play.

CONCLUSIONS

Sampling frequencies of 1 Hz are too low to accurately measure distance and speed during wheelchair tennis. GPS units with a higher sampling rate should be advocated in further studies. Modifications to existing DL devices may be required to increase measurement precision. Further research into the validity of movement devices during match play will further inform the demands and movement patterns associated with wheelchair tennis.

Effects of rolling resistances on handrim kinetics during the performance of wheelies among manual wheelchair users with a spinal cord injury

STUDY DESIGN

Repeated cross-sectional study.

OBJECTIVES

To compare the effects of rolling resistances (RRs) on handrim kinetic intensity at the non-dominant upper limb and on handrim kinetic symmetry during wheelies performed by manual wheelchair users (MWUs) with spinal cord injury (SCI).

SETTING

Pathokinesiology Laboratory.

METHODS

Sixteen individuals with SCI who were able to perform wheelies participated in this study. During a laboratory assessment, participants randomly performed wheelies on four RRs: natural high-grade composite board, 5-cm thick soft foam, 5-cm thick memory foam, and with the rear wheels blocked by wooden blocks. Four trials were conducted for each of the RRs. Participant's wheelchair was equipped with instrumented wheels to record handrim kinetics, whereas the movements of the wheelchair were recorded with a motion analysis system.

RESULTS

The net mean and peak total forces, including its tangential and mediolateral components, were greater during take-off compared with the other phases of the wheelie, independently of RR. During take-off, the greatest net mean and peak total and tangential forces were reached with the wheels blocked. Symmetrical tangential and mediolateral force intensities were applied at the dominant and non-dominant handrims.

CONCLUSION

Wheelies performed on low or moderate density foam generate similar forces at the handrim than on a natural surface and significantly less forces than with the wheels blocked. Hence, when teaching individuals with an SCI to perform a stationary wheelie, the use of low or moderate density foam represents a valuable alternative for minimizing upper limb effort and may also optimize quasi-static postural steadiness.

Manual wheelchair use: bouts of mobility in everyday life

Background. This study aimed to describe how people move about in manual wheelchairs (MWCs) during everyday life by evaluating bouts of mobility or continuous periods of movement. Methods. A convenience sample of 28 MWC users was recruited. Participants' everyday mobility was measured using a wheel-mounted accelerometer and seat occupancy switch for 1-2 weeks. Bouts of mobility were recorded and characterized. Results. Across 29,200 bouts, the median bout lasted 21 seconds and traveled 8.6 m at 0.43 m/s. 85% of recorded bouts lasted less than 1 minute and traveled less than 30 meters. Participants' daily wheelchair activity included 90 bouts and 1.6 km over 54 minutes. Average daily occupancy time was 11 hours during which participants wheeled 10 bouts/hour and spent 10% of their time wheeling. Spearman-Brown Prophecy analysis suggested that 7 days were sufficient to achieve a reliability of 0.8 for all bout variables. Conclusions. Short, slow bouts dominate wheelchair usage in a natural environment. Therefore, clinical evaluations and biomechanical research should reflect this by concentrating on initiating movement, maneuvering wheelchairs, and stopping. Bouts of mobility provide greater depth to our understanding of wheelchair use and are a more stable metric (day-to-day) than distance or time wheeled.

Validation of an accelerometer-based method to measure the use of manual wheelchairs

The goal of this project was to develop and validate a methodology for measuring manual wheelchair movement. The ability to study wheelchair movement is necessary across a number of clinical and research topics in rehabilitation, including the outcomes of rehabilitation interventions, the long-term effects of wheelchair propulsion on shoulder health, and improved wheelchair prescription and design. This study used a wheel-mounted accelerometer to continuously measure distance wheeled, and to continuously determine if the wheelchair is moving. Validation of the system and algorithm was tested across typical mobility-related activities of daily living, which included short slow movements with frequent starts, stops, and turns, and straight, steady state propulsion. Accuracy was found to be greater than 90% across wheelchair and wheel types (spoke and mag), propulsion techniques (manual and foot), speeds, and everyday mobility-related activities of daily living. Although a number of approaches for wheelchair monitoring are currently present in the literature, many are limited in the data they provide. The methodology presented in this paper can be applied to a variety of commercially available products that record bi-axial accelerations, and used to answer many research questions in wheeled mobility.

Current research outcomes from the spinal cord injury model systems

This article serves as an introduction to this issue of the Archives of Physical Medicine and Rehabilitation that is devoted to current research findings of the Spinal Cord Injury Model Systems (SCIMS) program. The SCIMS program began in 1970, with funding from the National Institute on Disability and Rehabilitation Research in the U.S. Department of Education, to demonstrate a comprehensive care system for spinal cord injury (SCI) and also to conduct research to improve the health and quality of life of persons with SCI. Over the last 20 years, similar collaborative efforts for the dissemination of SCIMS research outcomes have produced conference proceedings in 1990, a book in 1995, and dedicated journal issues in 1999 and 2004. The collection of 24 articles in this issue shows the depth and breadth of work being carried out by the SCIMS investigators, from descriptive epidemiology to a randomized controlled trial, from neurologic recovery to community reintegration, and from health services utilization to assistive technology for mobility. Herein, we provide a brief overview of the SCIMS program, highlight the research initiatives currently underway, and describe the important findings of the original research articles contained in this issue.