Wheelchair Racing Research Articles

ASSOCIATION BETWEEN CORE MUSCLES ACTIVATION AND THE 400-METER OVERGROUND SPRINTING VELOCITY IN WHEELCHAIR RACERS

Objective: To measure the activity of the core muscles and the middle trapezius in T54 class wheelchair racers during full-effort over ground sprinting and to determine its association with propulsion velocity. Material and Method: Eightmale international wheelchair racershaving normal upper limband partial to normaltrunk function(T54 class athletes) propelled their racing wheelchairs on 400-m competition trackwith maximal effort. Electromyography(EMG)of the rectus abdominis (RA), iliocostalis lumborum (IL), longissimus thoracis (LT) and middle trapezius (MT) were recorded at each 100-m reach using a wireless surface EMG recorder. Percentage of maximal voluntary contraction (%MVC)was measuredand correlated with propulsion velocity. Results:Median %MVC of RA, IL, LT and MT were 54.2, 43.9, 30.6 and 35.6% respectively. Positive associationto propulsion velocity was found in RA (p = 0.04, r = 0.73). Negative association to propulsion velocity was also found in MT (p = 0.03, r = -0.77). Conclusion: Abdominal function wasactivated most andassociated with propulsion velocity in male T54 class wheelchair racers. In addition, optimizing scapularretraction may benefit propulsionvelocity.

Placement effects of inertial measurement units on contact identification in wheelchair racing

ABSTRACT Inertial measurement units (IMUs) provide a practical solution for attaining key performance data for wheelchair sports. The effects of IMU placement position on the identification of propulsion characteristics are unknown. The aim of this study was to determine the variability in the reliability of cycle time measurements (time between hand contacts) across IMU locations on the chair frame (axle housings), and wheels (axle, push rim, outer rim), on both the left and right sides (n = 8). Contacts were defined by spikes in the resultant acceleration data, corresponding to impact between the hands and push rim, and verified against motion capture. Five elite wheelchair racing athletes propelled at racing speeds on a treadmill. Excellent inter-rater Intraclass Correlation Coefficient values indicated high reliability and repeatability for both motion capture and IMU signal analysis approaches (R = 0.997, p < 0.001 and R = 0.990, p < 0.001, respectively). The best results were (as determined by the best between method agreement) were observed for IMUs located on the frame. Detection reliability was positively associated with signal-to-noise ratio of the acceleration data. The IMU assessment approach facilitates an automated processing capability, which is an improvement to the currently used video analysis.

Influence of wheelchair user interface and personal characteristics on static and dynamic pretibial skin pressures in elite wheelchair racers, a pilot study

Context/objective: To examine personal (athletic classification, age, sex, body mass index, duration of disability, tactile sensation of lower extremities) and wheelchair (kneeling plate angle) factors associated with increased pretibial skin pressures in elite wheelchair racers.Design: Cross-sectional study.Setting: University-based laboratory in Champaign, USA.Participants: A convenience sample of elite wheelchair races with traumatic spinal cord injury and spinal disease were recruited for participation.Interventions: Interface pressure mapping was used to examine athletes’ average and peak pretibial skin pressures in their own racing wheelchairs during static and dynamic (propulsive) conditions on a dynamometer.Outcome measures: The study examined associations between personal and wheelchair factors and pressure, differences in pressure between static and dynamic conditions, and the influence of athletic classification (T53 vs. T54) on kneeling plate angle preference and skin pressure magnitudes.Results: Increased kneeling plate angle was moderately associated with dynamic pressures. T53 athletes utilized more vertical kneeling angles and experienced larger average and peak pressures during propulsion. Duration of disability was negatively associated with all measures of pressure. Overall, mean dynamic peak pressure was significantly greater than mean static peak pressure.Conclusion: This pilot study represents a first step in understanding the influence of user interface on potentially injurious skin pressures in wheelchair racers. Vertical kneeling plate configurations were associated with increased pressures while increased years with disability was associated with lower pretibial pressures. In addition, T53 athletes with less trunk function may be at a greater risk for experiencing larger interface pressures than T54 athletes.

Physiological responses during a 25-km time trial in elite wheelchair racing athletes.

Observational study. To characterize the cardiorespiratory and metabolic response of elite wheelchair racing (WCR) athletes during a 25 km, field-based time trial. University laboratory and field racing course in Urbana, Illinois, USA. Seven elite WCR athletes (4 men/3 women) with spinal cord injury completed an incremental exercise test to exhaustion on a computerized wheelchair roller system to determine peak cardiorespiratory capacity in the laboratory. The athletes then completed a long-distance, field-based time trial (i.e., 25 km) within 5 days. Energy expenditure was measured continuously during the time trial with a portable metabolic unit. Blood samples were collected to determine blood lactate and glucose concentrations. Core temperature was measured using an ingestible sensor thermistor. Five participants completed the long-distance time trial with usable cardiorespiratory data. Median heart rate and oxygen consumption during the time trial was 93.6% and 76.6% of peak values, respectively. Median energy expenditure was 504.6 kcal/h. There was a significant increase in blood lactate concentration from 0.7 to 4.0 mmol/L after the time trial (p = 0.03). There were no changes in blood glucose concentrations after the time trial (p = 0.27). Lastly, core temperature significantly increased from 37.1 at baseline to 38.7 °C immediately after the time trial (p = 0.01). Elite WCR athletes sustained a high exercise intensity that was consistent across the long-distance time trial, and exercise intensity outcomes were generally lower than those documented for elite able-bodied long-distance athletes in other studies. Our findings provide accurate estimates of energy expenditure that can be used to design effective training and racing strategies for elite WCR athletes.

Estimation of mechanical power and energy cost in elite wheelchair racing by analytical procedures and numerical simulations

The aim was to compare the mechanical power and energy cost of an elite wheelchair sprinter in the key-moments of the stroke cycle. The wheelchair-athlete system was 3D scanned and then computational fluid dynamics was used to estimate the drag force. Mechanical power and energy cost were derived from a set of formulae. The effective area in the catch, release and recovery phases were 0.41 m2, 0.33 m2 and 0.24 m2, respectively. Drag increased with speed and varied across the key-moments. The catch required the highest total power (range: 62.76–423.46 W), followed-up by the release (61.50–407.85 W) and the recovery (60.09–363.89 W).

Energetic Profile of a Wheelchair Racing 1500 m Simulation Test

Energetic Profile of a Wheelchair Racing 1500 m Simulation Test

Monitoring seating interface pressure in wheelchair sports

A robust method of quantifying athlete movement and pressure distribution across the seating interface of wheelchair athletes is required for athlete monitoring, optimising athlete performance, and computational simulations. The purpose of this study was to investigate whether a pressure mat is capable of measuring the distribution of pressure during wheelchair sport motion, and analyse the relationship between an athlete’s pressure distribution and their movement at the seating interface. Pressure was measured at the seating interface (wheelchair racing, n = 6, wheelchair rugby, n = 2) under conditions of steady state (racing athletes only), acceleration from stationary (racing and rugby), and agility (rugby only). All athletes demonstrated large within-trial variation in average pressure, peak pressure, and contact area for the acceleration and agility (rugby only) trials, suggesting the change in requirements of the seating interface for wheelchair athletes across different motions. This research suggests the need for greater individualisation of athlete–wheelchair seating interfaces to promote performance, as well as the importance of including these seating interactions in biomechanical analyses of wheelchair propulsion. Regular monitoring of pressure distribution and sport specific demands will assist in wheelchair prescription and provide improved understanding of individual seat design requirements associated with specific athlete impairments.

Peak oxygen uptake in Paralympic sitting sports: A systematic literature review, meta- and pooled-data analysis.

BackgroundPeak oxygen uptake (VO2peak) in Paralympic sitting sports athletes represents their maximal ability to deliver energy aerobically in an upper-body mode, with values being influenced by sex, disability-related physiological limitations, sport-specific demands, training status and how they are tested.ObjectivesTo identify VO2peak values in Paralympic sitting sports, examine between-sports differences and within-sports variations in VO2peak and determine the influence of sex, age, body-mass, disability and test-mode on VO2peak.DesignSystematic literature review and meta-analysis.Data sourcesPubMed, CINAHL, SPORTDiscusTM and EMBASE were systematically searched in October 2016 using relevant medical subject headings, keywords and a Boolean.Eligibility criteriaStudies that assessed VO2peak values in sitting sports athletes with a disability in a laboratory setting were included.Data synthesisData was extracted and pooled in the different sports disciplines, weighted by the Dersimonian and Laird random effects approach. Quality of the included studies was assessed with a modified version of the Downs and Black checklist by two independent reviewers. Meta-regression and pooled-data multiple regression analyses were performed to assess the influence of sex, age, body-mass, disability, test mode and study quality on VO2peak.ResultsOf 6542 retrieved articles, 57 studies reporting VO2peak values in 14 different sitting sports were included in this review. VO2peak values from 771 athletes were used in the data analysis, of which 30% participated in wheelchair basketball, 27% in wheelchair racing, 15% in wheelchair rugby and the remaining 28% in the 11 other disciplines. Fifty-six percent of the athletes had a spinal cord injury and 87% were men. Sports-discipline-averaged VO2peak values ranged from 2.9 L∙min-1 and 45.6 mL∙kg-1∙min-1 in Nordic sit skiing to 1.4 L∙min-1 and 17.3 mL∙kg-1∙min-1 in shooting and 1.3 L∙min-1 and 18.9 mL∙kg-1∙min-1 in wheelchair rugby. Large within-sports variation was found in sports with few included studies and corresponding low sample sizes. The meta-regression and pooled-data multiple regression analyses showed that being a man, having an amputation, not being tetraplegic, testing in a wheelchair ergometer and treadmill mode, were found to be favorable for high absolute and body-mass normalized VO2peak values. Furthermore, high body mass was favourable for high absolute VO2peak values and low body mass for high body-mass normalized VO2peak values.ConclusionThe highest VO2peak values were found in Nordic sit skiing, an endurance sport with continuously high physical efforts, and the lowest values in shooting, a sport with low levels of displacement, and in wheelchair rugby where mainly athletes with tetraplegia compete. However, VO2peak values need to be interpreted carefully in sports-disciplines with few included studies and large within-sports variation. Future studies should include detailed information on training status, sex, age, test mode, as well as the type and extent of disability in order to more precisely evaluate the effect of these factors on VO2peak.

Incidence of Shoulder Injury in Elite Wheelchair Athletes Differ Between Sports: A Critically Appraised Topic.

Clinical Scenario: Until recently, injury epidemiology data on elite Paralympic athletes were limited. Current data suggest high rates of shoulder injury in wheelchair athletes. Differences in shoulder injury rates between sports have not been reported in this population. Clinical Question: Is the incidence of shoulder injury in elite wheelchair athletes different between sports? Summary of Key Findings: Shoulder injury rates are high in elite wheelchair athletes, particularly in sports such as field events and fencing that require a stable base (eg,trunk, core control) from which to perform. Wheelchair racing requires repetitive motions that contribute to shoulder injuries, but rates are lower than field sports and fencing. Wheelchair curling and sledge hockey have low shoulder injury risk. Clinical Bottom Line: Shoulder injury rates vary based on sport in elite wheelchair athletes. In addition to incorporating shoulder complex specific rehabilitation for overuse shoulder injuries, clinicians should focus on core and trunk stabilization in elite wheelchair athletes competing in sports, such as field events and fencing. Strength of Recommendation: Grade C evidence exists that reports shoulder injury rates among elite wheelchair athletes differ based on sport participation.

Circulating Progenitor Cell Response to Exercise in Wheelchair Racing Athletes.

Circulating progenitor cells (CPC) are a heterogeneous population of stem/progenitor cells in peripheral blood that participate in tissue repair. CPC mobilization has been well characterized in able-bodied persons but has not been previously investigated in wheelchair racing athletes. The purpose of this study was to characterize CPC and CPC subpopulation mobilization in elite wheelchair racing athletes in response to acute, upper-extremity aerobic exercise to determine whether CPC responses are similar to ambulatory populations. Eight participants (three females; age = 27.5 ± 4.0 yr, supine height = 162.5 ± 18.6 cm, weight = 53.5 ± 10.9 kg, V˙O2peak = 2.4 ± 0.62 L·min, years postinjury = 21.5 ± 6.2 yr) completed a 25-km time trial on a road course. Blood sampling occurred before and immediately after exercise for quantification of CPC (CD34), hematopoietic stem and progenitor cells (HSPC) (CD34/CD45), hematopoietic stem cells (HSC) (CD34/CD45/CD38), CD34 adipose tissue (AT)-derived mesenchymal stromal cells (MSC) (CD45/CD34/CD105/CD31), CD34 bone marrow (BM)-derived MSC (CD45/CD34/CD105/CD31), and endothelial progenitor cells (EPC) (CD45/CD34/VEGFR2) via flow cytometry. Blood lactate was measured before and after trial as an indicator of exercise intensity. CPC concentration increased 5.7-fold postexercise (P = 0.10). HSPC, HSC, EPC, and both MSC populations were not increased postexercise. Baseline HSPC populations were significantly positively correlated to absolute V˙O2peak (rho = 0.71, P < 0.05) with HSC trending to positively correlate to V˙O2peak (rho = 0.62, P = 0.10). AT-MSC populations were trending to be negatively correlated to baseline V˙O2peak (rho = -0.62, P = 0.058). The change in CPC, EPC, and AT-MSC pre- and postexercise significantly positively correlated to the change in lactate concentrations (rho = 0.91 P = 0.002, 0.71 P = 0.047, 0.81 P = 0.02, respectively, all P < 0.05). These data suggest that CPC content in wheelchair racing athletes is related to cardiorespiratory fitness, and responses to exercise are positively related to exercise intensity.

Cluster analysis of novel isometric strength measures produces a valid and evidence-based classification structure for wheelchair track racing

BackgroundThe Para athletics wheelchair-racing classification system employs best practice to ensure that classes comprise athletes whose impairments cause a comparable degree of activity limitation. However, decision-making is largely subjective and...

Experimental Protocol of a Three-minute, All-out Arm Crank Exercise Test in Spinal-cord Injured and Able-bodied Individuals.

Reliable exercise protocols are required to test changes in exercise performance in elite athletes. Performance improvements in these athletes may be small; therefore, sensitive tools are fundamental to exercise physiology. There are currently many exercise tests that allow for the examination of exercise capacity in able-bodied athletes, with protocols mainly for lower-body or whole-body exercise. There is a trend to test athletes in a sport-specific setting that closely resembles the actions that the participants are used to performing. Only a few protocols test short-term, high-intensity exercise capacity in participants with an impairment of the lower body. Most of these protocols are very sport-specific and are not applicable to a wide range of athletes. One well-known test protocol is the 30 s Wingate test, which is well-established in cycling and in arm crank exercise testing. This test analyzes high-intensity exercise performance over a 30 s time duration. In order to monitor exercise performance over a longer duration, a different method was modified for application to the upper body. The 3 min, all-out arm crank ergometer test allows athletes to be tested in a manner specific to 1,500 m wheelchair racing (in terms of exercise duration), as well as to upper body exercises such as rowing or hand-cycling. In order to increase the reliability with identical test conditions, it is crucial to precisely replicate settings such as the resistance (i.e., torque factor) and the position of the participants (i.e., the height of the crank, the distance between the crank and the participant, and the fixation of the participant). Another important issue concerns the beginning of the exercise test. Fixed revolutions per minute are required to standardize the test conditions for the start of the exercise test. This exercise protocol shows the importance of accurate operations to reproduce identical test conditions and settings.

Physiological Responses To A Simulated Half-marathon Road-race In Elite Wheelchair Racing Athletes

Physiological Responses To A Simulated Half-marathon Road-race In Elite Wheelchair Racing Athletes

Analysis of Time Distribution Pattern and Surface Electromyography Characteristics of Wheelchair Racing “Butterfly” Technique

Analysis of Time Distribution Pattern and Surface Electromyography Characteristics of Wheelchair Racing “Butterfly” Technique

Expert Users' Perceptions of Racing Wheelchair Design and Setup: The Knowns, Unknowns, and Next Steps.

This paper demonstrates how a qualitative methodology can be used to gain novel insights into the demands of wheelchair racing and the impact of particular racing chair configurations on optimal sport performance via engagement with expert users (wheelchair racers, coaches, and manufacturers). We specifically explore how expert users understand how wheels, tires, and bearings impact sport performance and how they engage, implement, or reject evidence-based research pertaining to these components. We identify areas where participants perceive there to be an immediate need for more research especially pertaining to the ability to make individualized recommendations for athletes. The findings from this project speak to the value of a qualitative research design for capturing the embodied knowledge of expert users and also make suggestions for "next step" projects pertaining to wheels, tires, and bearings drawn directly from the comments of participants.

The development of Swiss wheelchair athletics. The key role of the Swiss Association of Paraplegics (1982-2015)

The international achievements and regular participation of Swiss ‘wheelchair racers’ are noteworthy. With 144 medals since 1976 in both individual and relay races, a group of 19 athletes has won 45% of the medals taken by Switzerland in all categories of the summer Paralympic Games. In this paper, we will answer the question: how has this paralympic elite been constructed institutionally since the 1980s, when Swiss wheelchair athletes intensified their participation in the Paralympic Games? By studying the manufacture of this exemplar of sporting excellence through written sources and some 15 interviews, we underline the central role played by the Swiss Group for Paraplegics in the development of Swiss wheelchair athletics. Its novel sports policies were based on considerable human and financial means, an advanced medical environment, good sports infrastructure and the constant recruitment of former champions.

シミュレーションモデルを用いた車いすマラソンのパフォーマンス評価

シミュレーションモデルを用いた車いすマラソンのパフォーマンス評価

Recent Salient Literature Pertaining to the Use of Technology in Wheelchair Sports

Adapted sports are increasingly recognized as a potent rehabilitative tool for persons with disabilities (PWD), facilitating optimal levels of health and wellbeing. At the same time, increased participation in adapted sports stimulates concomitant growth in technology and innovation worldwide. Success in wheelchair sports is said to be dependent on three factors: the athlete, the wheelchair, and the interaction between the athlete and the wheelchair. Proper use of technology has the potential to impact all the three factors significantly. In recent years, researchers have focused on the investigation of technologies impacting user interface, equipment customization, injury prevention, and performance improvement. This article presents a review of recent publications with a technological focus, selected for their importance and relevance to the field of wheelchair sports (wheelchair rugby, basketball, tennis, handcycling, and wheelchair racing) and for their potential to inform the decision-making process of athletes, coaches, and other healthcare professionals active in the arena of adaptive sports.

Contribution of limb momentum to power transfer in athletic wheelchair pushing

Pushing capacity is a key parameter in athletic racing wheelchair performance. This study estimated the potential contribution of upper limb momentum to pushing. The question is relevant since it may affect the training strategy adopted by an athlete. A muscle-free Lagrangian dynamic model of the upper limb segments was developed and theoretical predictions of power transfer to the wheelchair were computed during the push phase. Results show that limb momentum capacity for pushing can be in the order of 40J per push cycle at 10m/s, but it varies with the specific pushing range chosen by the athlete. Although use of momentum could certainly help an athlete improve performance, quantifying the actual contribution of limb momentum to pushing is not trivial. A preliminary experimental investigation on an ergometer, along with a simplified model of the upper limb, suggests that momentum is not the sole contributor to power transfer to a wheelchair. Muscles substantially contribute to pushing, even at high speeds. Moreover, an optimal pushing range is challenging to find since it most likely differs if an athlete chooses a limb momentum pushing strategy versus a muscular exertion pushing strategy, or both at the same time. The study emphasizes the importance of controlling pushing range, although one should optimize it while also taking the dynamics of the recovery period into account.

Risk of Injuries in Paralympic Track and Field Differs by Impairment and Event Discipline

Background: The incidence rates (IRs) and factors associated with injuries in the sport of Paralympic athletics (track and field) have not been comprehensively and prospectively studied. Purpose: To determine injury IRs, characteristics of injuries, and associated factors in the sport of athletics at the London 2012 Paralympic Games. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 977 athletes competing in the sport of athletics were followed over a total 10-day competition period of the Paralympic Games. Daily injury data were obtained via 2 databases: (1) a custom-built, web-based injury and illness surveillance system (WEB-IISS), maintained by team medical personnel; and (2) the organizing committee database, maintained by medical providers in the medical stations operated by the London Organising Committee of the Olympic and Paralympic Games. Athlete impairment and event discipline were obtained via the International Paralympic Committee athlete database. IRs (injuries per 1000 athlete-days) by impairment, event discipline, sex, and age were examined. Results: The overall IR was 22.1 injuries per 1000 athlete-days (95% CI, 19.5-24.7). In track disciplines, ambulant athletes with cerebral palsy experienced a lower incidence of injuries (IR, 10.2; 95% CI, 4.2-16.2) when compared with ambulant athletes from other impairment categories. Athletes in seated throwing experienced a higher incidence of injuries (IR, 23.7; 95% CI, 17.5-30.0) when compared with athletes in wheelchair racing (IR, 10.6; 95% CI, 5.5-15.6). In both track and field disciplines, the majority of injuries did not result in time loss from competition or training. Ambulant athletes experienced the greatest proportion of injuries to the thigh (16.4% of all injuries; IR, 4.0), observed predominantly in track athletes. Wheelchair or seated athletes experienced the greatest proportion of injuries to the shoulder/clavicle (19.3% of all injuries; IR, 3.4), observed predominantly in field athletes. Conclusion: This is the first prospective cohort study examining injury IRs and associated factors in the sport of athletics at the Paralympic Games. Injury patterns were specific to the event discipline and athlete impairment. The majority of injuries occurred to the thigh (ambulant athletes) or shoulder/clavicle (wheelchair or seated athletes) and did not result in time loss.