Wheelchair Configuration Research Articles

Investigating the Haptic Perception of Directional Information Within a Handle.

This paper studies the perception of 2-dimensional directional cues presented on a hand-held tangible interface that resembles a cylindrical handle. The tangible interface is designed to be comfortably held with one hand and houses five custom electromagnetic actuators composed of coils as stators and magnets as movers. We carried out a human subjects experiment enrolling 24 participants, analysing the recognition rate of directional cues using the actuators either to vibrate or tap in sequence across the user's palm. Results show an impact of the positioning/holding of the handle, the mode of stimulation, and the directional indication sent via the handle. There was also a correlation between the score and the confidence of the participants, showing that participants are more confident when recognising vibration patterns. Overall, results supported the potential of the haptic handle to provide accurate guidance, with recognition rates higher than 70 % in all conditions and higher than 75 % in the precane and power wheelchair configurations.

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

Clinical practice guidelines for preservation of upper extremity recommend minimizing wheelchair propulsion forces. Our ability to make quantitative recommendations about the effects of wheelchair configuration changes is limited by system-level tests to measure rolling resistance (RR). We developed a method that directly measures caster and propulsion wheel RR at a component-level. The study purpose is to assess accuracy and consistency of component-level estimates of system-level RR. The RR of N = 144 simulated unique wheelchair-user systems were estimated using our novel component-level method and compared to system-level RR measured by treadmill drag tests, representing combinations of caster types/diameters, rear wheel types/diameters, loads, and front-rear load distributions. Accuracy was assessed by Bland-Altman limits of agreement (LOA) and consistency by intraclass correlation (ICC). Overall ICC was 0.94, 95% CI [0.91-0.95]. Component-level estimates were systematically lower than system-level (-1.1N), with LOA +/-1.3N. RR force differences between methods were constant over the range of test conditions. Component-level estimates of wheelchair-user system RR are accurate and consistent when compared to a system-level test method, evidenced by small absolute LOA and high ICC. Combined with a prior study on precision, this study helps to establish validity for this RR test method.

Manual Wheelchair Configuration in Unilateral Upper- and Lower-Extremity Propulsion: A Randomized Crossover Study to Assess Effects of Rear Wheel Axle Position and Frame Type

ObjectiveTo evaluate independence and exertion when using a lightweight wheelchair in comparison with ultra-lightweight wheelchairs (rigid and folding) for individuals with brain injury using a hemipropulsion technique. DesignRandomized cross-over. SettingRehabilitation hospital. ParticipantsIndividuals diagnosed with brain injury resulting in hemiplegia using a hemipropulsion technique to mobilize in a manual wheelchair for at least 4 hours per day were recruited for this study. InterventionsEighteen participants were randomly assigned to complete skills and endurance testing in 3 different wheelchair configurations over a 3-week period: lightweight wheelchair; ultra-lightweight folding wheelchair; and ultra-lightweight rigid wheelchair. Main Outcome MeasuresThe primary outcome in this study was the percentage capacity score from the modified Wheelchair Skills Test 4.1. Secondary outcomes included the Wheelchair Propulsion Test, 100-m Push Test, heart rate, and rate of perceived exertion. ResultsSignificant differences were found in the Wheelchair Skills Test (total score, low rolling resistance score, and the goal attainment score) favoring the ultra-lightweight wheelchairs over the lightweight wheelchair (P=.002, .001, and .016, respectively). Time to complete the 100-m push test was significantly faster for the ultra-lightweight rigid frame in comparison with the lightweight frame (P=.001; 30.89 seconds faster). Significance differences were not seen with the Wheelchair Propulsion Test measures across any of the wheelchair frames. Heart rate change and of perceived exertion were significantly lower for the ultra-lightweight rigid group in comparison with the lightweight group (P=.006 and .013, respectively). ConclusionsThese data suggest that using an ultra-light weight wheelchair may lead to improved ability to complete wheelchair skills needed for successful mobility and a decrease in the actual and perceived physiological burden associated with propulsion in comparison to a lightweight wheelchair. A rigid frame may also enable faster mobility in comparison to a folding frame when hemi-propelling.

Effects of Wheel and Tire Selection on High-Strength Lightweight Manual Wheelchair Propulsion Cost Using Robotic Propulsion

<h3>Research Objectives</h3> To investigate the effects of wheel and tire selections on the propulsion characteristics of a high-strength lightweight manual wheelchair, a robotic propulsion device was deployed across a cohort of wheelchair configurations. <h3>Design</h3> This experimental study compared the mechanical behaviors of four wheelchair configurations with differing drive wheels and casters. <h3>Setting</h3> This study was conducted in a laboratory setting. Test surfaces (linoleum tile, low-pile carpet) represented common environments where high-strength lightweight wheelchairs are used. <h3>Participants</h3> No human subjects were used in this study. One high-strength lightweight wheelchair frame (Viper Plus GT, Drive Medical) was used for all four configurations. The baseline configuration reflected the default manufacturer configuration, comprising a solid mag drive wheel and solid 8"x1" caster. The other three configurations included Primo 6"x1.5" caster wheels and solid 24"x1-3/8" Primo XPress drive tires. <h3>Interventions</h3> The Anatomical Model Propulsion System (AMPS) robotic wheelchair tester propelled the chair using pre-generated straight and curvilinear maneuvers using repeatable and reliable cyclic torque profiles across tile and carpet. <h3>Main Outcome Measures</h3> The main outcome measure was propulsion cost, defined as the ratio of mechanical energy required to propel the wheelchair to the total distance traveled over-ground, reported in Joules per meter. In addition, the metric of 'value' – the retail cost of components in comparison to their relative impact on the energetic propulsion cost – was proposed for the first time in relation to high-strength lightweight wheelchair components. <h3>Results</h3> Results indicate significant reduction in propulsion cost across all maneuvers and surfaces with upgraded casters (<24%), drive wheel tires (<23%), or both (<41%). The total retail cost differential between the full sets of default components and upgraded components was $33 (USD). <h3>Conclusions</h3> This study demonstrated that better casters and drive wheel tires can improve the performance of high-strength lightweight wheelchairs and better meet the mobility needs of users. Furthermore, gaining knowledge of component-level energy losses could inform users, clinicians, and manufacturers on 'better' components that are available in each context of use. <h3>Author(s) Disclosures</h3> The authors do not have any conflicts to disclose.

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 rehabilitation Wheel and tire selection can have a demonstrable impact on the propulsion efficiency of manual wheelchairs Coast-down test protocols can be used as a simple and cost-effective means of assessing representative energy losses across various surfaces Wheelchair configurations can be optimized with proper knowledge of the main energetic loss contributions and the environments and contexts of use

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

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

Update on the Evidence: RESNA Ultralight Manual Wheelchair Position Paper

<h3>Research Objectives</h3> To identify optimal manual wheelchair configuration for people who self-propel for full-time wheeled mobility. To identify new evidence on how prescribing an ultralight weight manual wheelchair can minimize secondary complications in the body functions, promote functional independence with mobility related activities of daily living, and provide opportunities to participate in life roles <h3>Design</h3> This position paper was written following a scoping literature review process, open review period through RESNA and peer-review process. <h3>Setting</h3> This position paper is relevant to any prescribers or clinicians recommending manual wheelchairs. The results of the scoping review is applicable to treatment settings where people use a manual wheelchair for primary mobility, from pediatrics to long term care. <h3>Participants</h3> N/A. <h3>Interventions</h3> The RESNA Paper on the Application of Ultralight Manual Wheelchairs was published in 2012 and sought to provide evidence to support the application of fully customizable manual ultralight weight wheelchairs. Since that time, new developments in clinical research in our understanding of manual wheelchair considerations have prompted a revision of this foundational document. <h3>Main Outcome Measures</h3> The presentation will describe the intention of the revision and review new evidence based topics incorporated into the new position paper including: Manual wheelchair configuration, wheelchair training and wheelchair skills relating to function, rolling resistance and propulsion effort, various propulsion styles and considerations for overuse injuries in all extremities. <h3>Results</h3> The results of the scoping literature review and position paper will provide supportive evidence for the need for ultralight weight manual wheelchair configuration and the impact on body functions and structures, activities of daily living, and participation. <h3>Conclusions</h3> This scoping review and position paper will allow the clinician and practitioner to have supportive evidence for equipment recommendation for their patients who use a manual wheelchair full-time for mobility. <h3>Author(s) Disclosures</h3> Jennith Bernstein is a full-time employee of Permobil, Inc.; however, this work is presented on behalf of an entire work group of clinicians, engineers, and professors.

How Can Biomechanics Improve Physical Preparation and Performance in Paralympic Athletes? A Narrative Review.

Recent research in Paralympic biomechanics has offered opportunities for coaches, athletes, and sports practitioners to optimize training and performance, and recent systematic reviews have served to summarize the state of the evidence connecting biomechanics to Paralympic performance. This narrative review serves to provide a comprehensive and critical evaluation of the evidence related to biomechanics and Paralympic performance published since 2016. The main themes within this review focus on sport-specific body posture: the standing, sitting, and horizontal positions of current summer Paralympic sports. For standing sports, sprint and jump mechanics were assessed in athletes with cerebral palsy and in lower-limb amputee athletes using running-specific prostheses. Our findings suggest that running and jumping-specific prostheses should be ‘tuned’ to each athlete depending on specific event demands to optimize performance. Standing sports were also inclusive to athletes with visual impairments. Sitting sports comprise of athletes performing on a bike, in a wheelchair (WC), or in a boat. WC configuration is deemed an important consideration for injury prevention, mobility, and performance. Other sitting sports like hand-cycling, rowing, and canoeing/kayaking should focus on specific sitting positions (e.g., arm-crank position, grip, or seat configuration) and ways to reduce aero/hydrodynamic drag. Para-swimming practitioners should consider athlete-specific impairments, including asymmetrical anthropometrics, on the swim-start and free-swim velocities, with special considerations for drag factors. Taken together, we provide practitioners working in Paralympic sport with specific considerations on disability and event-specific training modalities and equipment configurations to optimize performance from a biomechanical perspective.

Wearable Wheelchair Mobility Performance Measurement in Basketball, Rugby, and Tennis: Lessons for Classification and Training.

Athlete impairment level is an important factor in wheelchair mobility performance (WMP) in sports. Classification systems, aimed to compensate impairment level effects on performance, vary between sports. Improved understanding of resemblances and differences in WMP between sports could aid in optimizing the classification methodology. Furthermore, increased performance insight could be applied in training and wheelchair optimization. The wearable sensor-based wheelchair mobility performance monitor (WMPM) was used to measure WMP of wheelchair basketball, rugby and tennis athletes of (inter-)national level during match-play. As hypothesized, wheelchair basketball athletes show the highest average WMP levels and wheelchair rugby the lowest, whereas wheelchair tennis athletes range in between for most outcomes. Based on WMP profiles, wheelchair basketball requires the highest performance intensity, whereas in wheelchair tennis, maneuverability is the key performance factor. In wheelchair rugby, WMP levels show the highest variation comparable to the high variation in athletes’ impairment levels. These insights could be used to direct classification and training guidelines, with more emphasis on intensity for wheelchair basketball, focus on maneuverability for wheelchair tennis and impairment-level based training programs for wheelchair rugby. Wearable technology use seems a prerequisite for further development of wheelchair sports, on the sports level (classification) and on individual level (training and wheelchair configuration).

Modeling manual wheelchair propulsion cost during straight and curvilinear trajectories.

Minimizing the effort to propel a manual wheelchair is important to all users in order to optimize the efficiency of maneuvering throughout the day. Assessing the propulsion cost of wheelchairs as a mechanical system is a key aspect of understanding the influences of wheelchair design and configuration. The objective of this study was to model the relationships between inertial and energy-loss parameters to the mechanical propulsion cost across different wheelchair configurations during straight and curvilinear trajectories. Inertial parameters of an occupied wheelchair and energy loss parameters of drive wheels and casters were entered into regression models representing three different maneuvers. A wheelchair-propelling robot was used to measure propulsion cost. General linear models showed strong relationships (R2 > 0.84) between the system-level costs of propulsion and the selected predictor variables representing sources of energy loss and inertial influences. System energy loss parameters were significant predictors in all three maneuvers. Yaw inertia was also a significant predictor during zero-radius turns. The results indicate that simple energy loss measurements can predict system-level performance, and inertial influences are mostly overshadowed by the increased resistive losses caused by added mass, though weight distribution can mitigate some of this added cost.

The influence of operator and wheelchair factors on wheelchair propulsion effort

Purpose: The goal of this study was to evaluate the relative influence of operator and wheelchair factors on propulsion effort during over-ground wheelchair manoeuvres.Method: This observational study included 23 full-time manual wheelchair users and 13 able-bodied subjects. The operator factors included shoulder position, aerobic capacity and propulsion strength. The wheelchair factors included system mass, weight distribution, and frictional loss in straight and turning trajectories. The performance of over-ground manoeuvres was defined as the propulsion effort measured by VO2 as operators propelled along a modified figure-8 course on tile and carpet surfaces.Results: According to our regression model, shoulder position was the only significant contributor within operator factors, whereas weight distribution was the only significant contributor within wheelchair factors in influencing propulsion efforts. When combining operator and mechanical factors in the regression model, weight distribution became the only significant contributor to influence propulsion effort.Conclusion: Weight distribution and shoulder position had a significant influence on propulsion effort. These variables are related to the operator’s relationship to the drive wheels. However, system mass and muscle strength had the least influence on wheelchair manoeuvres. Our finding can help clinicians to improve wheelchair configurations and manufacturers to improve wheelchair design by understanding the importance of shoulder position and weight distribution.Implication for rehabilitationStudying wheelchair manoeuvers by considering both wheelchair and operator factors might provide a unique insight to address the complex interactions among wheelchair designs and users.Propulsion effort decreases as percentage weight is increased on the drive wheels and the shoulder becomes more aligned with the axle position, which highlights the need to optimize wheelchair axle position.Wheelchair configuration, as represented by weight distribution, had a more significant influence on everyday manoeuvre than wheelchair mass does.It is essential for wheelchair users to choose a wheelchair that can match their daily needs and anthropometric measurements for saving propulsion efforts.

Mechanism design and analysis of a proposed wheelchair-exoskeleton hybrid robot for assisting human movement

Abstract. As a conventional mobile assistance device, a wheelchair makes people suffer from skin injuries such as bed sores and ulcer, owing to sitting on a wheelchair for a long period. And the wheelchair is barely able to adapt to complex terrains, such as stairs. With the development of robotic technology, the rise of lower-limb exoskeleton robotics provides a new means of motion assistance, and provides training of motor ability. However, it can't support a user to compete long-distance movement because a user need consume much energy to keep balance. Considering the merits and demerits of wheelchairs and exoskeletons, we propose a novel hybrid motion assistant robot that combines both. The biggest challenge is the design of a mechanism that can transform the robot from a wheelchair into an exoskeleton, as well as the reverse transformation. To achieve this goal, the mechanism must be able to achieve three configurations: the wheelchair configuration, the support configuration, and the exoskeleton configuration. To reduce the weight of the robot and make it more compact, the linkages and actuators in the mechanism are designed to be reusable when the configuration changes. The mechanism is designed based on the analysis of functional requirements, and distributed synthesis of the mechanism is adopted. The kinematics and statics of every configuration are discussed in detail, to obtain the most reasonable dimensions using the particle swarm optimization algorithm. The mechanism performance is simulated and verified using ADAMS software. Finally, an experimental prototype is constructed for preliminary tests.

Manual wheelchair downhill stability: an analysis of factors affecting tip probability

BackgroundFor people who use manual wheelchairs, tips and falls can result in serious injuries including bone fractures, concussions, and traumatic brain injury. We aimed to characterize how wheelchair configuration changes (including on-the-fly adjustments), user variables, and usage conditions affected dynamic tip probability while rolling down a slope and contacting a small block.MethodsRigid body dynamic models of a manual wheelchair and test dummy were created using multi-body software (Madymo, TASS International, Livonia, MI), and validated with 189 experiments. Dynamic stability was assessed for a range of seat angles (0 to 20° below horizontal), backrest angles (0 to 20°), rear axle positions (0 to 20 cm from base of backrest), ground slopes (0 to 15°), bump heights (0 to 4 cm), wheelchair speeds (0 to 20 km/hr), user masses (50 to 115 kg), and user positions (0 to 10 cm from base of backrest). The tip classifications (forward tip, backward tip, rolled over bump, or stopped by bump) were investigated using a nominal logistic regression analysis.ResultsFaster wheelchair speeds significantly increased the probability of tipping either forward or backward rather than stopping, but also increased the probability of rolling over the bump (p < 0.001). When the rear axle was positioned forward, this increased the risk of a backward tip compared to all other outcomes (p < 0.001), but also reduced the probability of being stopped by the bump (p < 0.001 compared to forward tip, p < 0.02 compared to rolling over). Reclining the backrest reduced the probability of a forward tip compared to all other outcomes (p < 0.001), and lowering the seat increased the probability of either rolling over the bump or tipping backwards rather than tipping forward (p < 0.001). In general, the wheelchair rolled over bumps < 1.5 cm, and forwards tipping was avoided by reducing the speed to 1 km/hr.ConclusionsThe probability of forward tipping, corresponding to the greatest risk of injury, was significantly reduced for decreased speeds, smaller bumps, a reclined backrest, and a lower rear seat height. For wheelchairs with dynamic seating adjustability, when travelling downhill, on-the-fly adjustments to the seat or backrest can increase the likelihood of safely rolling over a bump.

Manual Wheelchair Configuration and Seating Considerations in the Spinal Cord Injury Population

To assess findings of selected articles investigating the effects of wheelchair configuration, back selection, and cushion selection for the active manual wheelchair user with spinal cord injury. Manual wheelchair configuration, cushion selection, and backrest setup have far reaching impacts on the user’s health and functional ability. Pressure ulcers, orthopedic deformities, and upper extremity pain may by avoided with a thoughtfully prescribed manual wheelchair and custom configuration. A properly configured wheelchair may prevent the development of secondary consequences of spinal cord injury, reduce overall medical costs, improve quality of life, and increase participation for manual wheelchair users living with spinal cord injury.

Sprint performance and propulsion asymmetries on an ergometer in trained high- and low-point wheelchair rugby players.

The purpose of this study was to examine the propulsion asymmetries of wheelchair athletes while sprinting on an instrumented, dual-roller ergometer system. Eighteen experienced wheelchair rugby players (8 low point (LP) (class ≤1.5) and 10 high point (HP) (class ≥2.0)) performed a 15-second sprint in their sports wheelchair on the instrumented ergometer. Asymmetry was defined as the difference in distance and power output (PO) between left and right sides when the best side reached 28m. Propulsion techniques were quantified based on torque and velocity data. HP players covered an average 3m further than the LP players (P=.002) and achieved faster sprint times than LP players (6.95±0.89 vs 8.03±0.68seconds, P=.005) and at the time the best player finished (5.96seconds). Higher peak POs (667±108 vs 357±78W, P=.0001) and greater peak speeds that were also evident were for HP players (4.80±0.71 vs 4.09±0.45m/s, P=.011). Greater asymmetries were found in HP players for distance (1.86±1.43 vs 0.70±0.65m, P=.016), absolute peak PO (P=.049), and speed (0.35±0.25 vs 0.11±0.10m/s, P=.009). Although HP players had faster sprint times over 28m (achieved by a higher PO), high standard deviations show the heterogeneity within the two groups (eg, some LP players were better than HP players). Quantification of asymmetries is important not only for classifiers but also for sports practitioners wishing to improve performance as they could be addressed through training and/or wheelchair configuration.

Wheelchair Mobility Performance Enhancement by Changing Wheelchair Properties: What Is the Effect of Grip, Seat Height, and Mass?

To provide insight on the effect of wheelchair settings on wheelchair mobility performance (WMP). Twenty elite wheelchair basketball athletes of low (n = 10) and high classification (n = 10) were tested in a wheelchair-basketball-directed field test. Athletes performed the test in their own wheelchairs, which were modified for 5 additional conditions regarding seat height (high-low), mass (central-distributed), and grip. The previously developed inertial-sensor-based WMP monitor was used to extract wheelchair kinematics in all conditions. Adding mass showed most effect on WMP, with a reduced average acceleration across all activities. Once distributed, additional mass also reduced maximal rotational speed and rotational acceleration. Elevating seat height had an effect on several performance aspects in sprinting and turning, whereas lowering seat height influenced performance minimally. Increased rim grip did not alter performance. No differences in response were evident between low- and high-classified athletes. The WMP monitor showed sensitivity to detect performance differences due to the small changes in wheelchair configuration. Distributed additional mass had the most effect on WMP, whereas additional grip had the least effect of conditions tested. Performance effects appear similar for both low- and high-classified athletes. Athletes, coaches, and wheelchair experts are provided with insight into the performance effect of key wheelchair settings, and they are offered a proven sensitive method to apply in sport practice, in their search for the best wheelchair-athlete combination.

Impact of rear wheel axle position on upper limb kinematics and electromyography during manual wheelchair use

Manual wheelchair propulsion is an important form of mobility for people with lower limb disabilities. Changes in the wheelchair configuration can affect, range of motion (ROM) of the upper limb joints, muscle actions and system stability. The purpose of this study is to investigate the impact of adjusting wheelchair configurations on upper body joints kinematics and muscle recruitment for able-bodied non experienced manual wheelchair users through applying a marker-based 3D motion analysis technique. Ten healthy male subjects were characterised for three wheelchair configurations, set by adjusting the horizontal axle position of both rear wheels by (3 cm) and (6 cm) posteriorly from the original position set by the manufacturer. Selected 3D kinematic and surface electromyography (sEMG) parameters of the upper body joints and shoulder muscles were measured in the Cardiff University Motion Analysis Laboratory. During the propulsion trials, trunk flexion/extension, lateral bending and axial rotation were evaluated within the average range of (7.50°±1.4°), (5.91°±1.23°) and (7.01°±3.91°), respectively. Dominant shoulder abduction/adduction, flexion/extension and internal/external rotation were evaluated within the average range of (24.63°±6.38°), (17.31°±4.27°) and (40.02°±12.35°), respectively. Dominant elbow pronation/supination and flexion/extension were evaluated within the range of (15.49°±7.70°) and (34.37°±8.38°), respectively. Dominant wrist radial/ulnar deviation and flexion/ extension were evaluated within the average range of (29.82°±8.97°) and (53.59°±9.65°), respectively. With normalising the muscle EMG to the percentage of MVC activity, posterior deltoid had the highest average EMG muscle activity (11.43 ± 5.33) during the propulsion trials and at the three wheel adjustments relative to the other dominant shoulder muscles. Other average muscles activities were evaluated as (6.99 ± 2.37) for upper trapezius, (6.89 ± 2.51) for triceps brachii, (5.39 ± 2.95) for anterior deltoid, (3.26 ± 1.00) for biceps brachii and (3.14 ± 1.26) for pectoralis major as the lowest average activity. The findings of this study indicate that changing rear wheel axle position posteriorly is correlated with increasing the kinematic ROMs of the trunk and dominant upper limb and the sEMG activities of the muscles predominantly involved with the recovery phase of propulsion which could be linked with higher risks of musculoskeletal disorders. This knowledge may help professionals when designing and prescribing wheelchairs that are more proper to users’ functional characteristics, accordingly profiting them improved quality of life.

Sensitivity to change of the field-based Wheelchair Mobility Performance Test in wheelchair basketball.

The Wheelchair Mobility Performance (WMP) test is a reliable and valid measure to assess mobility performance in wheelchair basketball. The aim of this study was to examine the sensitivity to change of the WMP test by manipulating wheelchair configurations. Sixteen wheelchair basketball players performed the WMP test 3 times in their own wheelchair: (i) without adjustments ("control condition"); (ii) with 10 kg additional mass ("weighted condition"); and (iii) with 50% reduced tyre pressure ("tyre condition"). The outcome measure was time (s). If paired t-tests were significant (p <0.05) and differences between conditions were larger than the standard error of measurement, the effect sizes (ES) were used to evaluate the sensitivity to change. ES values ≥0.2 were regarded as sensitive to change. The overall performance times for the manipulations were significantly higher than the control condition, with mean differences of 4.40 s (weight - control, ES = 0.44) and 2.81 s (tyre - control, ES = 0.27). The overall performance time on the WMP test was judged as sensitive to change. For 8 of the 15 separate tasks on the WMP test, the tasks were judged as sensitive to change for at least one of the manipulations. The WMP test can detect change in mobility performance when wheelchair configurations are manipulated.

Improving Mobility Performance in Wheelchair Basketball.

This study aimed to investigate which characteristics of athlete, wheelchair and athlete-wheelchair interface are the best predictors of wheelchair basketball mobility performance. A total of 60 experienced wheelchair basketball players performed a wheelchair mobility performance test to assess their mobility performance. To determine which variables were the best predictors of mobility performance, forward stepwise linear regression analyses were performed on a set of 33 characteristics, including 10 athlete, 19 wheelchair, and 4 athlete-wheelchair interface characteristics. A total of 8 of the characteristics turned out to be significant predictors of wheelchair basketball mobility performance. Classification, experience, maximal isometric force, wheel axis height, and hand rim diameter-which both are interchangeable with each other and wheel diameter-camber angle, and the vertical distance between shoulder and rear wheel axis-which was interchangeable with seat height-were positively associated with mobility performance. The vertical distance between the front seat and the footrest was negatively associated with mobility performance. With this insight, coaches and biomechanical specialists are provided with statistical findings to determine which characteristics they could focus on best to improve mobility performance. Six out of 8 predictors are modifiable and can be optimized to improve mobility performance. These adjustments could be carried out both in training (maximal isometric force) and in wheelchair configurations (eg,camber angle).

Effects of Offense, Defense, and Ball Possession on Mobility Performance in Wheelchair Basketball.

The aim of this study was to determine to what extent mobility performance is influenced by offensive or defensive situations and ball possession and to what extent these actions are different for the field positions. From video analysis, the relative duration of the various wheelchair movements during team offense/defense and individual ball possession was compared in 56 elite wheelchair basketball players. A two-way analysis of variance indicated that during offense, the guards and forwards performed longer driving forward than during defense. Overall, centers stood still longer during offense than during defense. Without ball, centers performed driving forward longer than with ball possession. It is concluded that offense, defense, and ball possession influenced mobility performance for the different field positions. These differences can be used to design specific training protocols. Furthermore, field positions require potentially different specific wheelchair configurations to improve performance.