Kinematics of sport wheelchair propulsion

The interaction between wheelchair configuration and wheeling performance in wheelchair tennis: a narrative review

The number of wheelchair tennis players is rising internationally, yet from a scientific perspective little is known about wheelchair tennis performance. Wheelchair tennis is more complex compared to other wheelchair court sports, due to the wheelchair/racket interaction. The purpose of this narrative review was to gain insight into the influence of wheelchair configuration, i.e., the individual set-up of a wheelchair, on wheelchair tennis performance, more specifically on wheelchair mobility performance and propulsion technique. Wheelchair propulsion while holding a racket has had little attention in both the wheelchair mobility performance and wheelchair propulsion technique area. It is shown that the propulsion technique and wheelchair mobility performance are negatively affected by the racket. Based on the current literature, the influence of wheelchair configuration on wheeling performance in wheelchair tennis can mainly be described from a broader wheelchair court sport perspective, due to the lack of specific publications about wheelchair tennis. In the future more research should be conducted on wheeling performance and wheelchair configuration in wheelchair tennis, to attain a more proper scientific foundation for optimising wheelchair tennis performance.

Impact of floor covering on wheelchair rugby players: analysis of rolling performance

Introduction

Despite the increased interest in indoor wheelchair sports in many countries, research on the effect of floor coverings on sports performance is limited. Currently, there are no specific guidelines for covering characteristics for wheelchair sports, whether for competitive or recreational purposes. This study aimed to determine the impact of floor coverings on the biomechanical parameters of manual wheelchair propulsion for wheelchair rugby practice.

Methods

Ten wheelchair rugby players performed 6 maximum-velocity sprints over 20 meters, with a 20-second recovery time between sprints, on 3 different coverings, using their personal sports wheelchairs. The coverings were: wood parquet, Gerflor TX System Endurance®, and a plastic synthetic covering (balatum). Performance and propulsion technique variables were collected using inertial measurement units (265 Hz, Kinvent, France). Additionally, rolling resistance quantification tests were conducted on each covering.

Results

Rolling resistance was lowest on the wood parquet, with an average value of 3.98 ± 0.97 N. Best sprint performance was achieved on the wood parquet. The fatigue index on the parquet was significantly lower than on the balatum (p < 0.05).

Discussion

Our results highlight that floor surface influences both performance and propulsion technique variables. Therefore, we recommend performing wheelchair rugby training on wood parquet to optimize performance. It is also important to consider the impact of different coverings on sprint performance when organizing player rotations to maintain a high level of competition during tournaments.

Analyzing Intra-Cycle Velocity Profile and Trunk Inclination during Wheelchair Racing Propulsion

The analysis of intra-cycle velocity profile of manual wheelchair (MWC) users has been used to highlight the significant role of trunk inertia in propulsion biomechanics. Maximal wheelchair linear velocity has previously been observed to be reached after the release of the handrims both during sports activities and daily life propulsion. This paper provides a combined analysis of linear velocity and trunk kinematics in elite wheelchair racing athletes during straight-line propulsion at stabilized speeds. MWC and trunk kinematics of eight athletes (level: 7 elite, 1 intermediate; classification: T54 (5), T53 (2) and T52 (1)) were monitored during 400 m races using inertial measurement units. An average propulsion cycle was computed for each athlete. The main finding of this article is the difference in propulsion patterns among the athletes, exhibiting either 1, 2 or 3 peaks in their velocity profile. A second peak in velocity is usually assumed to be caused by the inertia of the trunk. However, the presence of a second velocity peak among more severely impaired athletes with little to no trunk motion can either be associated to the inertia of the athletes' arms or to their propulsion technique.

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

CONTEXT

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

OBJECTIVE

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

DESIGN

Observational study.

PARTICIPANTS

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

METHODS

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

OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

Alterations in shoulder kinematics are associated with shoulder pain during wheelchair propulsion sprints

The study purpose was to examine the biomechanical characteristics of sports wheelchair propulsion and determine biomechanical associations with shoulder pain in wheelchair athletes. Twenty wheelchair court‐sport athletes (age: 32 ± 11 years old) performed one submaximal propulsion trial in their sports‐specific wheelchair at 1.67 m/s for 3 min and two 10 s sprints on a dual‐roller ergometer. The Performance Corrected Wheelchair User's Shoulder Pain Index (PC‐WUSPI) assessed shoulder pain. During the acceleration phase of wheelchair sprinting, participants propelled with significantly longer push times, larger forces, and thorax flexion range of motion (ROM) than both the maximal velocity phase of sprinting and submaximal propulsion. Participants displayed significantly greater peak glenohumeral abduction and scapular internal rotation during the acceleration phase (20 ± 9° and 45 ± 7°) and maximal velocity phase (14 ± 4° and 44 ± 7°) of sprinting, compared to submaximal propulsion (12 ± 6° and 39 ± 8°). Greater shoulder pain severity was associated with larger glenohumeral abduction ROM (r = 0.59, p = 0.007) and scapular internal rotation ROM (r = 0.53, p = 0.017) during the acceleration phase of wheelchair sprinting, but with lower peak glenohumeral flexion (r = −0.49, p = 0.030), peak abduction (r = −0.48, p = 0.034), and abduction ROM (r = −0.44, p = 0.049) during the maximal velocity phase. Biomechanical characteristics of wheelchair sprinting suggest this activity imposes greater mechanical stress than submaximal propulsion. Kinematic associations with shoulder pain during acceleration are in shoulder orientations linked to a reduced subacromial space, potentially increasing tissue stress.

The Wheelchair Propulsion Wheel Rotation Angle Function Symmetry in the Propelling Phase: Motion Capture Research and a Mathematical Model

The movement of a wheelchair with manual propulsion depends on the kinematics of the human body and the forces exerted by the muscles. To design innovative wheelchair propulsion systems, the biomechanical parameters resulting from human interaction in this anthropotechnical system must be formalised. The research objectives were thus adopted: an analysis of the propulsion wheel angle of rotation resulting from the hand movement’s trajectory and the mathematical formalisation of the propulsion wheel angle of rotation described as a function of the propelling phase’s duration. The research was carried out using three variants of manually propelled wheelchairs on a group of 10 patients representing the same group (C50) of anthropometric dimensions. The research demonstrated that the function of the propulsion wheel angle of rotation shows the features of central symmetry occurring at an angle of rotation of φ 52° and a propelling phase duration of 58%. Moreover, the measurements were averaged and a mathematical model of the propulsion wheel rotation function during the propulsion phase was developed, depending on the percentage of duration.

Deep Learning-Based Myoelectric Potential Estimation Method for Wheelchair Operation

Wheelchair sports are recognized as an international sport, and research and support are being promoted to increase the competitiveness of wheelchair sports. For example, an electromyogram can observe muscle activity. However, it is generally used under controlled conditions due to the complexity of preparing the measurement equipment and the movement restrictions imposed by cables and measurement equipment. It is difficult to perform measurements in actual competition environments. Therefore, in this study, we developed a method to estimate myoelectric potential that can be used in competitive environments and does not limit physical movement. We developed a deep learning model that outputs surface myoelectric potentials by inputting camera images of wheelchair movements and the measured values of inertial sensors installed on wheelchairs. For seven subjects, we estimated the myoelectric potential during chair work, which is important in wheelchair sports. As a result of creating an in-subject model and comparing the estimated myoelectric potential with the myoelectric potential measured by an electromyogram, we confirmed a correlation (correlation coefficient 0.5 or greater at a significance level of 0.1%). Since this method can estimate the myoelectric potential without limiting the movement of the body, it is considered that it can be applied to the performance evaluation of wheelchair sports.

The Impact of the Human Body Position Changes During Wheelchair Propelling on Motion Resistance Force: A Preliminary Study

The aim of this research was to analyze the impact of the human body position changes caused by propelling a wheelchair with the pushrim propulsion on the value of motion resistance force. The discussed research works are in progress; therefore, the presented results should be treated as preliminary. The research was carried out in the group of six volunteers propelling a wheelchair of which frame was inclined, in respect to the horizontal plane, under the angle of 0 deg, 7 deg, and 14 deg. The area of the position variability of the human body center of gravity (COG) and the coefficients of wheelchair rolling resistance have been determined. Based on the measurements conducted, rolling resistance force FT and motion resistance force FR have been defined for three values of frame inclination angle. The determined force of rolling resistance Ft depended on the location of the COG of the human body and the value of the coefficients of rolling resistance of the front and rear wheels of a wheelchair. This force was a component of the resistance to motion FR, which also took into account the influence of gravity resulting from the inclination of the wheelchair on an inclined plane. For the tested inclination angles relative to the horizontal plane, the rolling resistance force ranged from 9.82 N to 22.81 N. Analyzing the variability of the rolling resistance force FT, it was found that for the final phase of the driving motion, it increased by 36% for the inclination angle of 0 deg and 43% for the inclination angle of 7 deg. Its increase was 48% for the inclination angle of 14 deg in relation to the human body position for the beginning of the driving motion. In the case of measuring the value of the resistance to motion FR, it was observed that, depending on the angle of the incline of the wheelchair, it ranged from 14.69 N to 256.33 N. The measurements conducted enabled the derivation of an analytical model for determining rolling resistance force depending on the position of the human body COG and the wheelchair inclination angle. The conducted research demonstrated the impact of the COG position on the changes of motion resistance force, thus expanding the state of knowledge, introducing a new parameter which, like a surface type and wheel type, affects motion resistances.

Performance, asymmetry and biomechanical parameters in wheelchair rugby players

The practice of the wheelchair rugby is becoming more and more worldwide. However, few biomechanical studies have focused on this sport. The aim of this study was to compare kinematic parameters of wheelchair rugby players, classified as defensive players (LP-D) versus offensive players (HP-O). Twenty-nine wheelchair rugby players (17 LP-D and 12 HP-O) performed a 20-m sprint test. The peak velocities, temporal parameters (propulsion phase time, deceleration phase time, cycle time and cycle frequencies) and asymmetries (the difference in peak velocities between the right and the left wheels) were measured at the acceleration and constant peak velocity phases of the sprint by an inertial measurement unit which was placed on each rear wheel. At the acceleration and constant peak velocity phases, peak velocities and cycle frequencies were higher in HP-O players than LP-D players. The deceleration phase times and the cycle times were higher in LP-D players than HP-O players. However, no significant difference in asymmetry was found between LP-D players and HP-O players. The HP-O players showed superior performance than the LP-D players, but they could be more exposed at risk of injury at their upper limbs than LP-D players.

The Symmetric Nature of the Position Distribution of the Human Body Center of Gravity during Propelling Manual Wheelchairs with Innovative Propulsion Systems

Objective: The main objective of the tests conducted was to analyze the position variability of the human body’s center of gravity during propelling the wheelchair, and to demonstrate the properties enabling the description of this variability by means of plane figures with a symmetry axis. A secondary objective was to show the impact of the used manual propulsion type and the wheelchair inclination angle in relation to the plane on the dimensions of the position variability areas of the center of gravity. Method and materials: Three patients participated in the research representing 50 centiles of anthropometric dimensions. Each patient carried out fifteen measurement tests on three wheelchairs for three inclination angles of the wheelchair frame in relation to the level. Each measurement test consisted of five propulsion cycles for which the positions of the center of gravity were determined with the sampling frequency of 100 Hz. The measured positions of the center of gravity were approximated with ellipses containing 95.4% of the measurements conducted, assuming their dimension scaling basis in the form of the double value of standard deviation defined based on the registered results. Results: Based on the measurements conducted, the average values of five ellipses parameters were determined for nine cases in which a variable was the type of wheelchair propulsion and its inclination angle in relation to the level. The area of the highest variability of the position of the center of gravity was measured for the wheelchair with a multispeed transmission. The average dimensions of the ellipse semi-axis amounted to 108.53 mm for the semi-axis a and 29.75 for the semi-axis b, the average position of the ellipse center amounted to x = 114.51 mm and y = −10.53 mm, and the average inclination angle of the ellipse α amounted to −6.92°. The area of the lowest variability of the position of the center of gravity was measured for the wheelchair with a hybrid transmission. In this case, the average dimensions of the ellipse semi-axis amounted to 64.07 mm for the semi-axis a and 33.85 for the semi-axis b; whereas, the average position of the ellipse center amounted to x = 245.13 mm and y = −28.24 mm, and the average inclination angle of the ellipse α amounted to −0.56°.

Biomechanical Relationships Between Manual Wheelchair Steering and the Position of the Human Body's Center of Gravity

The purpose of this investigation was to analyze the impact of differential steering of a wheelchair with a pushrim on changes in the position of the body's center of gravity. The method assumed measuring the wheelchair trajectory and the body's center of gravity and determining the transverse relocation of the measured body's center of gravity in relation to a point on the wheelchair trajectory. Twenty-seven measurement tests which demonstrated various wheelchair trajectories were carried out within the investigation. The trajectories were 10 to 15 m long and involved moving forward (test 2), reversing (test 3), turning left (test 1) and right (test 4). The factor of deviation of the center of gravity of human body from the wheelchair trajectory was determined for selected characteristic turning maneuvers. The measured values ranged from 51 to 192 mm. The impact of the wheelchair trajectory on the position of the body's center of gravity was demonstrated as a result of this investigation. Consequently, a trajectory deviation factor for relocation of the human body weight on one side of the wheelchair has been demonstrated.

Towards the Development of a Learning-Based Intention Classification Framework for Pushrim-Activated Power-Assisted Wheelchairs

There has been a growth in the design and use of power assist devices for manual wheelchairs (MWCs) to alleviate the physical load of MWC use. A pushrim-activated power-assisted wheel (PAPAW) is an example of a power assist device that replaces the conventional wheel of a MWC. Although the use of PAPAWs provides some benefits to MWC users, it can also cause difficulties in maneuvering the wheelchair. In this research, we examined the characteristics of wheelchair propulsion when using manual and powered wheels. We used the left and right wheels' angular velocity to calculate the linear and angular velocity of the wheelchair. Results of this analysis revealed that the powered wheel's controller is not optimally designed to reflect the intentions of a wheelchair user. To address some of the challenges with coordinating the pushes on PAPAWs, we proposed the design of a user-intention detection framework. We used the kinematic data of MWC experiments and tested six supervised learning algorithms to classify one of four movements: "not moving", "moving straight forward", "turning left", and "turning right". We found that all the classification algorithms determined the type of movement with high accuracy and low computation time. The proposed intention detection framework can be used in the design of learning-based controllers for PAPAWs that take into account the individualized characteristics of wheelchair users. Such a system may improve the experience of PAPAW users.

Anthropometry and Performance in Wheelchair Basketball

This study investigated whether anthropometric characteristics, generic and specific sprinting, agility, strength, and endurance capacity could differentiate between First-Division and Third-Division wheelchair basketball (WB) players. A First-Division WB team (n = 8; age = 36.05 ± 8.25 years, sitting body height = 91.38 ± 4.24 cm, body mass = 79.80 ± 12.63 kg) and a Third-Division WB team (n = 11; age = 31.10 ± 6.37 years, sitting body height = 85.56 ± 6.48 cm, body mass = 71.18 ± 17.63 kg) participated in the study. Wheelchair sprint, agility, strength, and endurance tests were performed. The First-Division team was faster (8.7%) in 20 m without the ball, more agile (13-22%), stronger (18-33%), covered more distance (20%) in the endurance test, and presented higher values of rate of perceived exertion for the exercise load (48%) than the Third-Division team. Moreover, the individual 20-m sprint time values correlated inversely with the individual strength/power values (from r = -0.54 to -0.77, p ≤ 0.05, n = 19). Wheelchair basketball coaches should structure strength and conditioning training to improve sprint and agility and evaluate players accordingly, so that they can receive appropriate training stimuli to match the physiological demands of their competitive level.

Constraints influencing sports wheelchair propulsion performance and injury risk

The Paralympic Games are the pinnacle of sport for many athletes with a disability. A potential issue for many wheelchair athletes is how to train hard to maximise performance while also reducing the risk of injuries, particularly to the shoulder due to the accumulation of stress placed on this joint during activities of daily living, training and competition. The overall purpose of this narrative review was to use the constraints-led approach of dynamical systems theory to examine how various constraints acting upon the wheelchair-user interface may alter hand rim wheelchair performance during sporting activities, and to a lesser extent, their injury risk. As we found no studies involving Paralympic athletes that have directly utilised the dynamical systems approach to interpret their data, we have used this approach to select some potential constraints and discussed how they may alter wheelchair performance and/or injury risk. Organism constraints examined included player classifications, wheelchair setup, training and intrinsic injury risk factors. Task constraints examined the influence of velocity and types of locomotion (court sports vs racing) in wheelchair propulsion, while environmental constraints focused on forces that tend to oppose motion such as friction and surface inclination. Finally, the ecological validity of the research studies assessing wheelchair propulsion was critiqued prior to recommendations for practice and future research being given.

Supporting the paralympic athlete: focus on wheeled sports

The complexity of wheelchair sports provides the scientist with a unique challenge. There are two major components that contribute towards 'wheeled sports' performance: the athlete and the chair. It is the interaction of these two components that enable wheelchair propulsion and the sporting movements required within a given sport. This article will describe three discrete case studies on how sport scientists have worked with Great Britain coaches and practitioners to help optimise training leading to a major competition through evidence base practise. A fourth area will describe on-going work designed to address the optimisation of wheelchair configurations for wheelchair court sports. It will focus on four sports: wheelchair racing, wheelchair tennis, wheelchair basketball and wheelchair rugby. The first topic will discuss the concept of pushing economy and mechanical efficiency of wheelchair propulsion. The second topic will show how technology assists the coaching process. The third topic will illustrate the concept of sports classification, and show how training volume 'in terms of basketball shooting' may need to be individually assigned and finally future research within wheelchair team sports and chair configurations will be examined.

Wheelchair basketball quantification

Classification systems are one of the key elements in sports for people with disability, including wheelchair basketball. Further scientific studies to validate classification systems are needed. This article describes the most relevant research, with emphasis on biomechanics.

The intra-push velocity profile of the over-ground racing wheelchair sprint start

The aim of this study was to analyse the first six pushes of a sprint start in over-ground racing wheelchair propulsion. One international male wheelchair athlete (age=28 years; body mass=60.6 kg; racing classification=T4) performed maximal over-ground sprint trials, over approximately 10 m, in his own racing wheelchair fitted with a velocometer. Each trial was filmed at 200 Hz using a "Pan and Tilt" system. Eight trials were manually digitised at 100 Hz. Raw co-ordinate data were smoothed and differentiated using a quintic spline routine. Across the period from pushes one to six the duration of each push cycle decreased (0.82+/-0.02-0.45+/-0.01 s) with the mean duration of the propulsive phase decreasing from 0.62+/-0.02 to 0.21+/-0.01 s and the recovery phase increasing from 0.20+/-0.01 to 0.24+/-0.02 s. The push-rim was contacted progressively closer to top dead centre and released progressively closer to bottom dead centre with each push. The data indicate that peak velocity occurred after release. The main findings of this study support the observation that racing wheelchair sprint propulsion is a complex form of locomotion and cannot be described accurately by using just the established definitions of a propulsive and a recovery phase.

Wheelchair propulsion biomechanics: implications for wheelchair sports

The aim of this article is to provide the reader with a state-of-the-art review on biomechanics in hand rim wheelchair propulsion, with special attention to sport-specific implications. Biomechanical studies in wheelchair sports mainly aim at optimising sport performance or preventing sport injuries. The sports performance optimisation question has been approached from an ergonomic, as well as a skill proficiency perspective. Sports medical issues have been addressed in wheelchair sports mainly because of the extremely high prevalence of repetitive strain injuries such as shoulder impingement and carpal tunnel syndrome. Sports performance as well as sports medical reflections are made throughout the review. Insight in the underlying musculoskeletal mechanisms of hand rim wheelchair propulsion has been achieved through a combination of experimental data collection under realistic conditions, with a more fundamental mathematical modelling approach. Through a synchronised analysis of the movement pattern, force generation pattern and muscular activity pattern, insight has been gained in the hand rim wheelchair propulsion dynamics of people with a disability, varying in level of physical activity and functional potential. The limiting environment of a laboratory, however, has hampered the drawing of sound conclusions. Through mathematical modelling, simulation and optimisation (minimising injury and maximising performance), insight in the underlying musculoskeletal mechanisms during wheelchair propulsion is sought. The surplus value of inverse and forward dynamic simulation of hand rim stroke dynamics is addressed. Implications for hand rim wheelchair sports are discussed. Wheelchair racing, basketball and rugby were chosen because of the significance and differences in sport-specific movement dynamics. Conclusions can easily be transferred to other wheelchair sports where movement dynamics are fundamental.

Three-dimensional kinematics of wheelchair propulsion

A three-dimensional (3-D) biomechanical model was used to determine upper extremity kinematics of 16 male subjects with low-level paraplegia while performing wheelchair propulsion (WCP). A six-camera VICON motion analysis system was used to acquire the coordinate data of ten anatomic markers. Joint axes for the wrist and elbow were defined along with the planes of motion for the upper arm (humerus) and trunk. The group's mean and standard deviation profiles were graphed for eight of the nine rotations measured during WCP. Variability in the intercycle and intersubject movement patterns were calculated using the root mean square standard deviation (RMS sigma) and the coefficient of variation (CV). Motion pattern similarities were quantified using the coefficient of multiple correlation (CMC). The intercycle (Nc > or = 6) motion patterns of individual subjects were highly consistent, similar, and repeatable during WCP. This was confirmed by low CVc values (3-31%), high CMCc values (0.724-0.996) and RMS sigma c values below 3.2 degrees. For the group, mean values of the propulsion velocity, cadence, and propulsion cycle duration were 89.7 m/min, 66.1 pushes/min, and 0.96 s, respectively. Humeral plane and rotation showed large excursions (76.1-81.6 degrees), while trunk lean and forearm carrying angle displayed relatively small ranges of motion (5.5-10.9 degrees). The intersubject (N3 = 16) motion patterns were less similar compared to individual intercycle patterns. This was evidenced by higher CVc values (12-128%) and lower CMC3 values (0.418-0.935). Intersubject humeral patterns were the most consistent while trunk lean was the least consistent. Intersubject root mean square standard deviations (RMS sigma c) were more than three times the corresponding intercycle values for all nine rotations.