Aerobic capacity and peak power output of elite quadriplegic games players

Elbow, wrist kinematics and shock transmission of backhand stroke in wheelchair tennis players

The aim was to compare the differences in kinematics of elbow and wrist and shock transmission of the upper extremity in wheelchair tennis players and able-bodied players (in standing and sitting position) during backhand strokes. Fifteen wheelchair tennis and 15 able-bodied tennis players enrolled. Electromagnetic system and trial-axial accelerometers were used to measure the difference in the kinematic parameters of the upper extremity and the impact vibration transferred across the wrist joint. The results indicated that wheelchair players demonstrated unique elbow and wrist kinematics, especially shorter total swing time, greater elbow flexion at preparation, lower wrist extension acceleration before impact, and smaller racket vibration at impact. Comparing to able-bodied players in standing, wheelchair players and players in sitting demonstrated significantly greater elbow joint flexion/extension angle, angular velocity, angular acceleration during extension, and wrist joint flexion angle. Wheelchair players also differ significantly with the players in sitting regarding elbow joint angular velocity and acceleration, and wrist joint flexion velocity. These adaptations and adjustments can be attributed to the missing lower extremity function and deficient trunk kinetic chain. The differences between wheelchair tennis players and able-bodied players in sitting could represent the progress as the wheelchair players moving from novices to experts.

Impact of Holding a Badminton Racket on Spatio-Temporal and Kinetic Parameters During Manual Wheelchair Propulsion

Introduction

Para badminton entered the Paralympic world for the first time with the 2021 Paralympic Games in Tokyo. The particularity of this sport lies in the handling of the wheelchair and the racket simultaneously. To the best of our knowledge, and considering the youthfulness of this sport, it appears that no study has looked at the impact of the badminton racket on the kinetic and spatiotemporal parameters. Therefore, the aim of our study was to investigate the impact of the badminton racket on the amplitude of kinetic and spatiotemporal parameters of wheelchair propulsion, considered as propulsion effectiveness and risk of injury criteria. We hypothesized that holding a badminton racket while propelling the wheelchair modifies the kinetics and temporal parameters of the athlete's propulsion due to the difficulty to hold the handrim, therefore decreasing propulsion effectiveness and increasing risk of injury.

Materials and Methods

For six 90-min sessions, 16 able-bodied individuals were introduced to badminton. No injuries hindered their propulsion. They had to propel with and without a racket held on the dominant side along a 20 m straight line at a constant velocity of 5 km/h. They all used the same sports wheelchair equipped with two instrumented wheels (SmartWheel).

Results

Participants increased their maximal total force and force rate of rise but decreased their fraction of effective force with their dominant hand compared to the non-dominant hand when using a racket. In addition, they decreased their fraction of effective force, push time, cycle time, and push angle, and increased their maximal propulsive moment, maximal total force, and force rate of rise when comparing the same dominant hand with and without the racket.

Discussion

Using a badminton racket modifies the athlete's force application in a way that is generally related to lower propulsion effectiveness and a higher risk for injury. Indeed, it seems that propulsion with a racket prevents from correctly grabbing the handrim.

Comparison between the 10- and the 30-s-long Wingate Anaerobic Test in summer Paralympic athletes with a lower limb impairment

Background

The 30-s-long Wingate Anaerobic Test (WAnT_30s) has some limitations in high-level athletes. A shorter version might be helpful for both clinical applications and performance assessment. The comparison between the traditional WAnT_30s and a shorter version has never been carried out yet in Paralympic athletes.

Aim

To assess if a 10-s-long Wingate Anaerobic Test (WAnT_10s) could be used to accurately assess and predict the anaerobic components of physical fitness as an alternative to the traditional WAnT_30s in male Paralympic athletes.

Methods

Forty-four trained male Paralympic Athletes grouped by severity of locomotor impairment completed the WAnT_30s and the WAnT_10s with an arm cranking ergometer. Differences between mean and peak power achieved throughout both WAnTs were analysed using a mixed-design analysis of variance and predictivity was assessed by stepwise linear regression analysis.

Results

In the whole sample, peak power values were similar (P > 0.005) in the two tests and the WAnT_10s mean power was significantly higher than that in the WAnT_30s (P < 0.005). Finally, the mean power measured during WAnT_30s showed high level of predictability from mean power measured during WAnT_10s and the Functional class (adjusted R2 = 0.906; P < 0.001).

Conclusion

The WAnT_10s is accurate to assess peak power, is definitively appropriate to evaluate the alactic anaerobic metabolism and seems able to predict the mean power as traditionally evaluated through a WAnT_30s in male Paralympic Athletes. Thus, it can be used to assess the anaerobic components of physical fitness in this athletic population.

Physiologic and Clinical Features of the Paralympic Athlete's Heart

Importance

Paralympic medicine is a newly adopted term to describe the varied health care issues associated with athletes in the Paralympics. Scarce scientific data, however, are currently available describing the cardiac remodeling in Paralympic athletes.

Objective

To investigate the physiological and clinical characteristics of the Paralympic athlete's heart and derive the normative values.

Design, Setting, and Participants

This is a single-center study on a relatively large cohort of Paralympic athletes, conducted at the Italian Institute of Sport Medicine and Science. Paralympic athletes free of cardiac or systemic pathologic conditions other than their cause of disability were selected for participation in the Paralympic Games from January 2000 to June 2014. Athletes were arbitrarily classified for disability in 2 groups: those with spinal cord injuries (SCI) and those with non-SCI (NSCI). Data analysis occurred from March 2019 to June 2020.

Main Outcomes and Measures

The primary outcome was the difference in cardiac remodeling in Paralympic athletes according to disability type and sports discipline type. Athletes underwent cardiac evaluation, including 12-lead and exercise electrocardiograms, echocardiography, and cardiopulmonary exercise testing.

Results

Among 252 consecutive Paralympic athletes (median [interquartile range (IQR)] age, 34 [29-41] years; 188 men [74.6%]), 110 had SCI and 142 had NSCI. Those with SCI showed a higher prevalence of abnormal electrocardiogram findings than those with NSCI (13 of 110 [11.8%] vs 6 of 142 [4.2%]; P = .003), smaller left ventricular end-diastolic dimension (median [IQR], 48 [46-52] vs 51 [48-54] mm; P = .001) and left ventricular mass index (median [IQR], 80.6 [69-94] vs 91.3 [80-108] g/m2; P = .001), and lower peak oxygen uptake (VO2) (median [IQR], 27.1 [2-34] vs 38.5 [30-47] mL/min/kg; P = .001) in comparison with those with NSCI. Regarding sport discipline, endurance athletes had a larger left ventricular cavity (median [IQR], 52 [47-54] vs 49 [47-53] mm; P = .006) and higher peak VO2 (median [IQR], 46 [39-55] vs 30 [25-35] mL/min/kg; P = .001) than athletes in nonendurance sports.

Conclusions and Relevance

Cardiac remodeling in Paralympic athletes differed by disability and sport discipline. Having NSCI lesions and engaging in endurance sports were associated with the largest left ventricular cavity and left ventricular mass and highest VO2 peak. Having SCI lesions and engaging in nonendurance disciplines, on the contrary, were associated with the smallest left ventricular cavity and mass and lowest VO2 peak.

Personalized Tests in Paralympic Athletes: Aerobic and Anaerobic Performance Profile of Elite Wheelchair Rugby Players

In Paralympic sports, the goal of functional classifications is to minimize the impact of impairment on the outcome of the competition. The present cross-sectional study aimed to investigate aerobic and anaerobic personalized tests in Paralympic athletes and to correlate them with the classification of the international wheelchair rugby federation (IWRF). Sixteen elite players of the Italian wheelchair rugby team volunteered for the study. Aerobic (incremental test to exhaustion) and anaerobic (Wingate 30s all-out test, 5 and 10-meter sprint test, shuttle test, isometric test) sport-performance measurements were correlated singularly or grouped (Z scores) with the classification point. Moreover, a multivariate permutation-based ranking analysis investigated possible differences in the overall level of performance among the adjacent classified groups of players, considering the scores of each test. A statistically significant correlation between the performance parameters and the IWRF functional classification considering both aerobic and anaerobic personalized tests was detected (0.58 ≤ r ≤ 0.88; 0.0260 ≤ p ≤ 0.0001). The multivariate permutation-based ranking analysis showed differences only for the low-pointers versus mid-pointers (p = 0.0195) and high-pointers (p = 0.0075). Although single performance parameters correlated with athletes’ classification point, results of the multivariate permutation-based ranking analysis seem to suggest considering only the most significant anaerobic and sport-specific performance parameters among athletes. These should be combined with the physical assessment and the qualitative observation, which are already part of the classification process to improve its effectiveness.

Assessment of the Relationship between Selected Factors and Stress-Coping Strategies in Handcyclists-A Preliminary Study

Background and Objectives: Playing competitive sports is associated with stress, especially during the starting season. Disabled athletes are additionally burdened with physical and/or emotional factors, resulting from the trauma they have experienced. The aim of the work was to assess the relationship between strategies of coping with stress and the level of education, category of disability and its duration of handcyclists before the competition. Materials and Methods: 44 handcyclists with a mean age of 41.8 ± 11.6, from European countries, were divided according to the severity of mobility impairments, education and duration of the disability. The participants were asked to fill in the Mini-COPE Inventory for Measuring Coping with Stress, which provided answers in writing to some sociodemographic questions regarding age, sex, education, type of mobility impairment and duration of the disability. Results: The subjects who had suffered spinal injury at the cervical section obtained the lowest scores regarding their subjective assessment of their active stress management in difficult situations (p = 0.007). They scored the lowest, 1.5 points, when asked about acceptance in difficult circumstances compared to those with university education (p = 0.02). A statistically significant correlation was found to exist between education levels and positive revaluation, acceptance and seeking instrumental support. A negative correlation was observed between education and sustained use of psychoactive substances and denial. Conclusions: Highly educated cyclists with short-lasting disability, damage to the lower spine section or amputations tend to cope better with stress than other study participants.

Spinal Cord Injury Impairs Cardiovascular Capacity in Elite Wheelchair Rugby Athletes

OBJECTIVE

To examine differences in heart rate (HR) responses during international wheelchair rugby competition between athletes with and without a cervical spinal cord injury (SCI) and across standardized sport classifications.

DESIGN

Observational study.

SETTING

The 2015 Parapan American Games wheelchair rugby competition.

PARTICIPANTS

Forty-three male athletes (31 ± 8 years) with a cervical SCI (n = 32) or tetraequivalent impairment (non-SCI, n = 11).

MAIN OUTCOME MEASURES

Average and peak HR (HRavg and HRpeak, respectively). To characterize HR responses in accordance with an athletes' International Wheelchair Rugby Federation (IWRF) classification, we separated athletes into 3 groups: group I (IWRF classification 0.5-1.5, n = 15); group II (IWRF classification 2.0, n = 15); and group III (IWRF classification 2.5-3.5, n = 13).

RESULTS

Athletes with SCI had lower HRavg (111 ± 14 bpm vs 155 ± 13 bpm) and HRpeak (133 ± 12 bpm vs 178 ± 13 bpm) compared with non-SCI (both P < 0.001). Average HR was higher in group III than in I (136 ± 25 bpm vs 115 ± 20 bpm, P = 0.045); however, SCI athletes showed no difference in HRavg or HRpeak between groups. Within group III, SCI athletes had lower HRavg (115 ± 6 bpm vs 160 ± 8 bpm) and HRpeak (135 ± 11 bpm vs 183 ± 11 bpm) than non-SCI athletes (both P < 0.001).

CONCLUSIONS

This study is the first to demonstrate attenuated HR responses during competition in SCI compared with non-SCI athletes, likely due to injury to spinal autonomic pathways. Among athletes with SCI, IWRF classification was not related to differences in HR. Specific assessment of autonomic function after SCI may be able to predict HR during competition and consideration of autonomic impairments may improve the classification process.

Effects of different increments in workload and duration on peak physiological responses during seated upper-body poling

PURPOSE

To compare the effects of test protocols with different increments in workload and duration on peak oxygen uptake ([Formula: see text]O_2peak), and related physiological parameters during seated upper-body poling (UBP).

METHODS

Thirteen upper-body trained, male individuals completed four UBP test protocols with increments in workload until volitional exhaustion in a counterbalanced order: 20 W increase/every 30 s, 20 W/60 s, 10 W/30 s and 10 W/60 s. Cardio-respiratory parameters and power output were measured throughout the duration of each test. Peak blood lactate concentration (bLa_peak) was measured after each test.

RESULTS

The mixed model analysis revealed no overall effect of test protocol on [Formula: see text]O_2peak, peak minute ventilation (VE_peak), peak heart rate (HR_peak), bLa_peak (all p ≥ 0.350), whereas an overall effect of test protocol was found on peak power output (PO_peak) (p = 0.0001), respiratory exchange ratio (RER) (p = 0.024) and test duration (p < 0.001). There was no difference in PO_peak between the 20 W/60 s (175 ± 25 W) and 10 W/30 s test (169 ± 27 W; p = 0.092), whereas PO_peak was lower in the 10 W/60 s test (152 ± 21 W) and higher in the 20 W/30 s test (189 ± 30 W) compared to the other tests (all p = 0.001). In addition, RER was 9.9% higher in the 20 W/30 s compared to the 10 W/60 s test protocol (p = 0.003).

CONCLUSIONS

The UBP test protocols with different increments in workload and duration did not influence [Formula: see text]O_2peak, and can therefore be used interchangeably when [Formula: see text]O_2peak is the primary outcome. However, PO_peak and RER depend upon the test protocol applied and the UBP test protocols can, therefore, not be used interchangeably when the latter is the primary outcome parameter.

Energy Expenditure as a Function of Activity Level After Spinal Cord Injury: The Need for Tetraplegia-Specific Energy Balance Guidelines

The World Health Organization recognizes obesity as a global and increasing problem for the general population. Because of their reduced physical functioning, people with spinal cord injury (SCI) face additional challenges for maintaining an appropriate whole body energy balance, and the majority with SCI are overweight or obese. SCI also reduces exercise capacity, particularly in those with higher-level injury (tetraplegia). Tetraplegia-specific caloric energy expenditure (EE) data is scarce. Therefore, we measured resting and exercise-based energy expenditure in participants with tetraplegia and explored the accuracy of general population-based energy use predictors. Body composition and resting energy expenditure (REE) were measured in 25 adults with tetraplegia (C4/5 to C8) and in a sex-age-height matched group. Oxygen uptake, carbon dioxide production, heart rate, perceived exertion, and exercise intensity were also measured in 125 steady state exercise trials. Those with motor-complete tetraplegia, but not controls, had measured REE lower than predicted (mean = 22% less, p < 0.0001). REE was also lower than controls when expressed per kilogram of lean mass. Nine had REE below 1200 kcal/day. We developed a graphic compendium of steady state EE during arm ergometry, wheeling, and hand-cycling. This compendium is in a format that can be used by persons with tetraplegia for exercise prescription (calories, at known absolute intensities). EE was low (55–450 kcal/h) at the intensities participants with tetraplegia were capable of maintaining. If people with tetraplegia followed SCI-specific activity guidelines (220 min/week) at the median intensities we measured, they would expend 563–1031 kcal/week. Participants with tetraplegia would therefore require significant time (4 to over 20 h) to meet a weekly 2000 kcal exercise target. We estimated total daily EE for a range of activity levels in tetraplegia and compared them to predicted values for the general population. Our analysis indicated that the EE values for sedentary through moderate levels of activity in tetraplegia fall well below predicted sedentary levels of activity for the general population. These findings help explain sub-optimal responses to exercise interventions after tetraplegia, and support the need to develop tetraplegia-specific energy-balance guidelines that reflects their unique EE situation.

Anthropometry, Body Composition, and Performance in Sport-Specific Field Test in Female Wheelchair Basketball Players

Data on the physical and performance characteristics of female wheelchair basketball (WB) players are scarce. In several countries female WB players train and compete with male players on mixed teams due to the limited total population of players, which would otherwise lead to large territorial spread for each team. Any differences in terms of physical characteristics and/or WB skill proficiency between male and female WB players would be relevant to team performance in mixed teams. This work examined anthropometry, body composition, and performance in a set of sport-specific field tests in a sample of 13 female WB players representing about 40% of the eligible population in Italy across a range of functional point scores (Point). Point is assigned on an ordinal scale from 1.0 (i.e., players with minimal functional potential) through to 4.5 (players with maximum functional potential). Our female sample was then compared against twice as many (n = 26) Point-matched (±0.5 points) male players. The two groups were similar for age (P = 0.191; effect size [d] = 0.2), self-reported duration of injury (P = 0.144, d = 0.6), WB experience (P = 0.178, d = 0.5), and volume of training (P = 0.293, d = 0.4). The large majority of measured linear anthropometric variables (10/13) were lower in female players than males (0.001 < P ≤ 0.041). Skinfold-estimated percent body fat was higher (+7.6%) in females (30.7 ± 6.0%; P < 0.001, d = 1.3). Mean performance was worse in female than in males in six out of seven sport-specific field tests, scores being significantly lower in females for the maximal pass (7.5 ± 2.0 m for females vs. 10.4 ± 2.8 m for males; P = 0.002, d = 1.2) and suicide tests (55.8 ± 6.4 s for females vs. 45.4 ± 6.7 s for males; P < 0.001, d = 1.6). When performance in subgroups of females (n = 9) chosen across a range of Point was compared with that of males assigned 1.0 or 1.5 Point less (each n = 9), performance differences between male and female WB players were partially and completely eliminated, respectively. This work contributed new data for characterizing the physique and performance of female WB players. Further, the results suggested that when male and female athletes compete together in mixed teams, a 1.5 points subtraction from female players is needed to match the real gender difference in performance.

Autonomic Nervous System in Paralympic Athletes with Spinal Cord Injury

Individuals sustaining a spinal cord injury (SCI) frequently suffer from sensorimotor and autonomic impairment. Damage to the autonomic nervous system results in cardiovascular, respiratory, bladder, bowel, and sexual dysfunctions, as well as temperature dysregulation. These complications not only impede quality of life, but also affect athletic performance of individuals with SCI. This article summarizes existing evidence on how damage to the spinal cord affects the autonomic nervous system and impacts the performance in athletes with SCI. Also discussed are frequently used performance-enhancing strategies, with a special focus on their legal aspect and implication on the athletes' health.

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

Background

Peak oxygen uptake (VO_2peak) 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.

Objectives

To identify VO_2peak values in Paralympic sitting sports, examine between-sports differences and within-sports variations in VO_2peak and determine the influence of sex, age, body-mass, disability and test-mode on VO_2peak.

Design

Systematic literature review and meta-analysis.

Data sources

PubMed, CINAHL, SPORTDiscus^TM and EMBASE were systematically searched in October 2016 using relevant medical subject headings, keywords and a Boolean.

Eligibility criteria

Studies that assessed VO_2peak values in sitting sports athletes with a disability in a laboratory setting were included.

Data synthesis

Data 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 VO_2peak.

Results

Of 6542 retrieved articles, 57 studies reporting VO_2peak values in 14 different sitting sports were included in this review. VO_2peak 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 VO_2peak 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 VO_2peak values. Furthermore, high body mass was favourable for high absolute VO_2peak values and low body mass for high body-mass normalized VO_2peak values.

Conclusion

The highest VO_2peak 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, VO_2peak 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 VO_2peak.

A 20×20m repeated sprint field test replicates the demands of wheelchair rugby

OBJECTIVES

To assess the physiological responses to, and the agreement between, a 20×20m repeated sprint field test and wheelchair rugby game play, as well as the reliability of the test.

DESIGN

Cross-sectional and longitudinal.

METHODS

Heart rate (HR), blood lactate ([La^-]_B), and ratings of perceived exertion (RPE) were collected in nineteen elite wheelchair rugby athletes before, during, and after a 20×20m repeated sprint field test and game play. Times to complete 5, 10, and 20m during the field test were also collected.

RESULTS

Peak HR and peak [La^-]_B were positively correlated during the field test (r=0.470, p=0.043), as were peak HR and peak speed (r=0.493, p=0.031), and peak [La^-]_B and peak speed (r=0.559, p=0.013). During game play, peak [La^-]_B was correlated with peak RPE (rho=0.703, p=0.001). Intra-class correlations (ICCs) between the field test and game play were significant for peak HR (ICC=0.922, p<0.001) and peak [La^-]_B (ICC=0.845, p<0.001). Bland-Altman analysis revealed good agreement between HR and [La^-]_B obtained during the field test and game play and excellent between-day reliability of the 20×20m sprint test.

CONCLUSIONS

The physiological demands of a 20×20m repeated sprint field test are similar to those of elite wheelchair rugby game play and the test is highly reliable. This simple to implement field test may be useful as a component of team selection and in assessing the effectiveness of training interventions or monitoring athletes across training phases.

The Compact Wheelchair Roller Dynamometer

The equipment for evaluating the propulsion of a wheelchair is very complex and expensive. To validate a new dynamometer prototype for assessing the propulsion capacity of wheelchairs, 21 healthy subjects (age: 20.9±2.4 yr; weight: 68.9±7.9 kg; height: 174.0±7.1 cm; BMI: 22.7±2.5 kg·m ⁻² ) who do not normally require wheelchairs performed a sprint protocol for 20 s after a 1-min warm-up. The power and rotation data acquired by the prototype (both right and left sides) were compared with those of a reference system via high-speed videography (240 fps). The results showed high levels of accordance (95% CI), excellent values for the intraclass correlation coefficient (ICC: .99; P <0.00), no significant differences in the rotation ( P =0.91) and power ( P =0.94) between the methods. The proposed equipment met the validation criteria and thus can be applied as a new tool for assessing wheelchair propulsion.

Autonomic testing for prediction of competition performance in Paralympic athletes

While we now appreciate that autonomic dysfunction can impact wheelchair rugby performance, this is currently not being assessed during classification, largely due to lack of a standardized and evidence-based strategy to assess autonomic function. Our aim, therefore, was to establish the optimal autonomic testing protocol that best predicts cardiovascular capacity during competition by comprehensively examining autonomic function in elite wheelchair rugby athletes with cervical SCI and thereby enhance the standardized classification. Twenty-six individuals with cervical SCI (C4-C8; AIS A, B, C) participated in this study during the 2015 Parapan American Games in Toronto, Canada. Clinic autonomic testing included: sympathetic skin responses, baseline hemodynamics, orthostatic challenge test, and cold-pressor tests. Further, we completed standard motor/sensory assessments and obtained each participants' International Wheelchair Rugby Federation classification. These clinic metrics were correlated to in-competition heart rate monitoring obtained during competition. The current study provides novel evidence that the change in systolic blood pressure during an orthostatic challenge test predicts approximately 50% of the in-competition peak heart rate (P<.001). Conversely, International Wheelchair Rugby Federation classification was poorly associated with in-competition peak heart rate (R² =.204; P<.05). Autonomic testing provides deep insight regarding preserved autonomic control after SCI that is associated with performance in elite wheelchair rugby athletes. As such, incorporating assessments of cardiovascular capacity in classification will help to ensure a level playing field and may obviate the need for practices such as boosting to gain an advantage due to poor cardiovascular control.

Exercise Intensity During Power Wheelchair Soccer

OBJECTIVE

To determine exercise intensity during power wheelchair soccer among a sample of persons with mobility impairments.

DESIGN

Cross-sectional descriptive.

SETTING

On-site training facilities of multiple power wheelchair soccer teams.

PARTICIPANTS

Participants with severe mobility impairments (N=30) (mean ± SD, age: 29.40±15.51y, body mass index: 24.11±6.47kg/m², power soccer experience: 7.91±3.93y, disability sport experience: 12.44±9.73y) were recruited from multiple power wheelchair soccer teams.

INTERVENTIONS

Portable metabolic carts were used to collect oxygen consumption (V˙o₂) data during resting and game play conditions.

MAIN OUTCOME MEASURES

Average V˙o₂ (expressed in metabolic equivalent tasks [METs]) during resting and game play conditions and rating of perceived exertion for game play.

RESULTS

V˙o₂ increased from 1.35±0.47 METs at rest to 1.81±0.65 METs during game play. This 34% increase in exercise intensity was significant (P<.01) and supported by a mean perceived exertion score of approximately 13 (somewhat hard).

CONCLUSIONS

Although not able to sustain an intensity associated with reduced secondary disease risk (ie, 3 METs), the documented light-intensity exercise in the current study surpassed an intensity threshold associated with improved functional capacity and performance of daily living activities (ie, 1.5 METs).

Effect of Three Different Grip Angles on Physiological Parameters During Laboratory Handcycling Test in Able-Bodied Participants

INTRODUCTION

Handcycling is a relatively new wheelchair sport that has gained increased popularity for people with lower limb disabilities. The aim of this study was to examine the effect of three different grip positions on physical parameters during handcycling in a laboratory setting.

METHODS

Twenty one able-bodied participants performed three maximum incremental handcycling tests until exhaustion, each with a different grip angle. The angle between the grip and the crank was randomly set at 90° (horizontal), 0° (vertical), or 10° (diagonal). The initial load was 20 W and increased by 20 W each 5 min. In addition, participants performed a 20 s maximum effort.

RESULTS

The relative peak functional performance (W/kg), peak heart rate (bpm), associated lactate concentrations (mmol/l) and peak oxygen uptake per kilogram body weight (ml.min(-1).kg(-1)) for the different grip positions during the stage test were: (a) Horizontal: 1.43 ± 0.21 W/kg, 170.14 ± 12.81 bpm, 9.54 ± 1.93 mmol/l, 30.86 ± 4.57 ml/kg; (b) Vertical: 1.38 ± 0.20 W/kg, 171.81 ± 13.87 bpm, 9.91 ± 2.29 mmol/l, 29.75 ± 5.13 ml/kg; (c) Diagonal: 1.40 ± 0.22 W/kg, 169.19 ± 13.31 bpm, 9.34 ± 2.36 mmol/l, 29.39 ± 4.70 ml/kg. Statistically significant (p < 0.05) differences could only be found for lactate concentration between the vertical grip position and the other grips during submaximal handcycling.

CONCLUSION

The orientation of three different grip angles made no difference to the peak load achieved during an incremental handcycling test and a 20 s maximum effort. At submaximal load, higher lactate concentrations were found when the vertical grip position was used, suggesting that this position may be less efficient than the alternative diagonal or horizontal grip positions.

Tracking of wheelchair rugby players in the 2008 Demolition Derby trial

The kinematics of male wheelchair rugby players (n = 8) during the final match of the 2008 Demolition Derby were assessed using two cameras (10 Hz) and a tracking method based on image-processing techniques. The players' on-court trajectory, total and accumulated distances covered, distances covered during working and stopped game clock, and average velocity were calculated. The players covered 2294.7 +/- 391.5 m in the first half and 2245.4 +/- 431.5 m in the second half. The average velocity was 14.5% greater in the first (1.22 +/- 0.21 m . s(-1)) than in the second half (1.05 +/- 0.20 m . s(-1)). The reduction in velocity was most marked in players with less functional capacity. The working game clock represented 48% of total game time (32 of 66.8 minutes) and the distance covered by all players during working game clock was 60% of the overall distance covered during the whole game (36,323 m). The results provide new information regarding the dynamics of a wheelchair rugby match and should aid coaches in planning effective training and coaching strategies.

The role of autonomic function on sport performance in athletes with spinal cord injury

Devastating paralysis, autonomic dysfunction, and abnormal cardiovascular control present significant hemodynamic challenges to individuals with spinal cord injury (SCI), especially during exercise. In general, resting arterial pressure after SCI is lower than with able-bodied individuals and is commonly associated with persistent orthostatic intolerance along with transient episodes of life-threatening hypertension, known as "autonomic dysreflexia." During exercise, the loss of central and reflexive cardiovascular control attenuates maximal heart rate and impairs blood pressure regulation and blood redistribution, which ultimately reduces venous return, stroke volume, and cardiac output. Thermoregulation also is severely compromised in high-lesion SCI, a problem that is compounded when competing in hot and humid conditions. There is some evidence that enhancing venous return via lower body positive pressure or abdominal binding improves exercise performance, as do cooling strategies. Athletes with SCI also have been documented to self-induce autonomic dysreflexia before competition with a view of increasing blood pressure and improving their performance, a technique known as "boosting." For health safety reasons, boosting is officially banned by the International Paralympics Committee. This article addresses the complex issue of how the autonomic nervous system affects sports performance in athletes with SCI, with a specific focus on the potential debilitating effects of deranged cardiovascular control.

Field-based physiological testing of wheelchair athletes

The volume of literature on field-based physiological testing of wheelchair sports, such as basketball, rugby and tennis, is considerably smaller when compared with that available for individuals and team athletes in able-bodied (AB) sports. In analogy to the AB literature, it is recognized that performance in wheelchair sports not only relies on fitness, but also sport-specific skills, experience and technical proficiency. However, in contrast to AB sports, two major components contribute towards 'wheeled sports' performance, which are the athlete and the wheelchair. It is the interaction of these two that enable wheelchair propulsion and the sporting movements required within a given sport. Like any other athlete, participants of wheelchair sports are looking for efficient ways to train and/or analyse their technique and fitness to improve their performance. Consequently, laboratory and/or field-based physiological monitoring tools used at regular intervals at key time points throughout the year must be considered to help with training evaluation. The present review examines methods available in the literature to assess wheelchair sports fitness in a field-based environment, with special attention on outcome variables, validity and reliability issues, and non-physiological influences on performance. It also lays out the context of field-based testing by providing details about the Paralympic court sports and the impacts of a disability on sporting performance. Due to the limited availability of specialized equipment for testing wheelchair-dependent participants in the laboratory, the adoption of field-based testing has become the preferred option by team coaches of wheelchair athletes. An obvious advantage of field-based testing is that large groups of athletes can be tested in less time. Furthermore, athletes are tested in their natural environment (using their normal sports wheelchair set-up and floor surface), potentially making the results of such testing more relevant than laboratory testing. However, given that many tests, such as the multistage fitness test and the Yo-Yo intermittent test, have originally been developed for AB games players, the assumption that these can also be used for wheelchair athletes may be erroneous. With the array of AB aerobic and anaerobic field tests available, it is difficult to ascertain which ones may be best suited for wheelchair athletes. Therefore, new, wheelchair sport-specific tests have been proposed and validated. Careful selection of tests to enable coaches to distinguish between disability classifications, wheelchair proficiency and actual performance improvements is paramount as this will not only enhance the value of field-based testing, but also help with the development of meaningful normative data.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Avaliação da potência aeróbia de praticantes de Rugby em Cadeira de Rodas através de um teste de quadra

O presente estudo teve por finalidade estimar a potência aeróbia em atletas com LME praticantes de RCR, correlacionar os níveis de VO2máx com a classificação funcional (CF) dos atletas e analisar o comportamento da FC antes e pós-teste. A amostra foi composta por 10 atletas com LME, do sexo masculino e idade média de 29,6±6,5anos. Os atletas foram submetidos ao teste de corrida de 12 minutos e monitorados com o frequêncimetro cardíaco. A média do VO2máx foi de 18,3±8,1ml(kg.min)-1 e da FCmáx de 114,6±25,3bpm. Os valores de VO2máx obtidos no estudo são classificados como médio para a população com tetraplegia. Observou-se que existe correlação moderada (r=0,77) entre a CF e o VO2máx entre atletas praticantes de RCR e por fim, observou-se baixos valores de FC frente á um teste submáximo, fato que pode estar relacionado à diminuição da atuação simpática após LME.

Autonomic modulation of heart rate in paraplegic wheelchair basketball players: Linear and nonlinear analysis

This study aimed to evaluate the autonomic modulation of heart rate in sedentary paraplegics and paraplegic wheelchair basketball players with thoracic spinal cord injury below T6. Seven paraplegic wheelchair basketball players (active paraplegic group), five paraplegics who were not involved in regular exercise (sedentary paraplegic group) and 10 able-bodied participants (control group) took part in the study. The heart rate variability was evaluated by linear (low frequency and high frequency band in normalised units and low frequency/high frequency ratio) and nonlinear methods (Shannon entropy, corrected conditional entropy, and symbolic analysis). The sedentary group presented significantly higher values for low frequency, low frequency/high frequency ratio and symbolic index with no significant variations (0V%), and also lower values for the high frequency and symbolic index with two significant unlike variation (2ULV%) compared to active paraplegic group. Shannon entropy and corrected conditional entropy analyses revealed significantly lower values in the sedentary group than in the control or active paraplegic groups. Paraplegic individuals who regularly undertake physical exercise have higher complexity of R-R interval time series, lower sympathetic modulation, and higher parasympathetic modulation than sedentary paraplegic participants.

Wheelchair tennis match-play demands: effect of player rank and result

PURPOSE

To examine the heart-rate (HR) response and court-movement variables during wheelchair tennis match play for high- (HIGH) and low- (LOW) performance-ranked players. Analysis of physiological and movement-based responses during match play offers an insight into the demands of tennis, allowing practical recommendations to be made.

METHODS

Fourteen male open-class players were monitored during tournament match play. A data logger was used to record distance and speed. HR was recorded during match play.

RESULTS

Significant rank-by-result interactions revealed that HIGH winners covered more forward distance than HIGH losers (P < .05) and had higher average (P < .05) and minimum (P < .01) HRs than LOW winners. LOW losers had higher average (P < .01) and minimum (P < .001) HRs than LOW winners. Independent of result, a significant main effect for rank was identified for maximum (P < .001) and average (P < .001) speed and total (P < .001), reverse (P < .001), and forward-to-reverse (P < .001) distance, with higher values for HIGH. Independent of rank, losing players experienced higher minimum HRs (P < .05). Main effects for maximum HR and actual playing time were not significant. Average playing time was 52.0 (9.1) min.

CONCLUSIONS

These data suggest that independent of rank, tennis players were active for sufficient time to confer health-enhancing effects. While the relative playing intensity is similar, HIGH players push faster and farther than LOW players. HIGH players are therefore more capable of responding to ball movement and the challenges of competitive match play. Adjustments to the sport may be required to encourage skill developmental in LOW players, who move at significantly lower speeds and cover less distance.

Partial heat acclimation of athletes with spinal cord lesion

Heat acclimation (HA) can improve thermoregulatory stability in able-bodied athletes in part by an enhanced sweat response. Athletes with spinal cord lesion are unable to sweat below the lesion and it is unknown if they can HA. Five paralympic shooting athletes with spinal cord lesion completed seven consecutive days HA in hot conditions (33.4 ± 0.6 °C, 64.8 ± 3.7 %rh). Each HA session consisted of 20 min arm crank exercise at 50 % [Formula: see text] followed by 40 min rest, or simulated shooting. Aural temperature (T (aur)) was recorded throughout. Body mass was assessed before and after each session and a sweat collection swab was fixed to T12 of the spine. Fingertip whole blood was sampled at rest on days 1 and 7 for estimation of the change in plasma volume. Resting T (aur) declined from 36.3 ± 0.2 °C on day 1 to 36.0 ± 0.2 °C by day 6 (P < 0.05). During the HA sessions mean, T (aur) declined from 37.2 ± 0.2 °C on day 1, to 36.7 ± 0.3 °C on day 7 (P < 0.05). Plasma volume increased from day 1 by 1.5 ± 0.6 % on day 7 (P < 0.05). No sweat secretion was detected or changes in body mass observed from any participant. Repeated hyperthermia combined with limited evaporative heat loss was sufficient to increase plasma volume, probably by alterations in fluid regulatory hormones. In conclusion, we found that although no sweat response was observed, athletes with spinal cord lesion could partially HA.

Validity of submaximal exercise testing in adults with athetospastic cerebral palsy

OBJECTIVE

To examine the validity of the multistage submaximal cycle ergometer test for adults with athetospastic cerebral palsy.

DESIGN

Cross-sectional and correlative study. Oxygen uptake and heart rates were recorded while the participants underwent the maximal cycle ergometer test and the multistage submaximal cycle ergometer test. Peak oxygen consumption (Vo(2)peak) was achieved by the maximal cycle test. Maximum oxygen consumption (VO(2)max) was predicted by the multistage submaximal cycle ergometer test.

SETTING

Research laboratory setting.

PARTICIPANTS

Adults with athetospastic cerebral palsy (N=16; 10 women and 6 men; mean age ± SD, 43.7±14.5y).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Peak VO(2) was compared with the predicted VO(2)max.

RESULTS

Mean VO(2)peak and the predicted VO(2)max ± SD were 866.9±202.9 mL/min(-1) and 857.4±248.4 mL/min(-1), respectively. There was not a significant difference between VO(2)peak values and the predicted VO(2)max values (r=.28). And there was a significant correlation between VO(2)peak values and the predicted VO(2)max values (r=.94, P<.001). SE of the estimate (or SE for X to Y) was 71.2 mL/min(-1), equivalent to 7.4%.

CONCLUSIONS

The multistage submaximal cycle ergometer test may provide a valid VO(2)max estimate of adults with athetospastic cerebral palsy.

Submaximal exercise responses in tetraplegic, paraplegic and non spinal cord injured elite wheelchair athletes

It remains unclear whether similar exercise prescription, based on physiological markers, can be applied to subgroups of wheelchair athletes with different disabilities. Therefore, 25 wheelchair athletes, divided into three subgroups [eight tetraplegic (TETRA), nine paraplegic (PARA) and eight non spinal cord injured (NON-SCI)], performed an exercise test consisting of incremental submaximal stages, covering a range from 40% to 80% peak oxygen uptake (%VO(2peak) ). Oxygen uptake (VO(2)), heart rate (HR), blood lactate concentration (BLa) and rating of perceived exertion (RPE) were obtained for each stage. Expressed as a function of BLa, no differences were found between subgroups with respect to %VO(2peak) (group mean ± SD: 1.0 mmol/L: 53.9 ± 9.9%; 2.0 mmol/L: 70.7 ± 7.5%; 3.0 mmol/L: 78.5 ± 7.7%) and RPE [group mean (lower and upper quartile): 1.0 mmol/L: 10.8 (9.9, 12.2); 2.0 mmol/L: 13.6 (12.7, 14.3); 3.0 mmol/L: 14.9 (13.7, 16.5)]. Furthermore, no differences were found in the coefficient of determination (R(2) ) of the HR-VO(2) relationship in any of the subgroups (TETRA: 0.90 ± 0.12; PARA: 0.97 ± 0.02; NON-SCI: 0.96 ± 0.04). These results suggest that exercise prescription using measurements of VO(2), BLa or RPE can be based on the same recommendations in all the subgroups studied. This finding has added value for TETRA athletes, as it offers alternatives to HR monitoring.

Aerobic, anaerobic, and skill performance with regard to classification in wheelchair rugby athletes

The purpose of the study was to examine the sport-specific performance of wheelchair rugby players with regard to their classification. A group of 30 male athletes from the Polish Wheelchair Rugby League participated in the study. The seven International Wheelchair Rugby Federation classes were collapsed into four groups. Standardized measures of aerobic, anaerobic, and skill performance were examined to identify performance differences among the four groups. Major findings were that most differences were between Group I players and all others and that anaerobic performance was the most sensitive to classification differences. Another important finding was that for all other groups, with one exception, adjacent groups did not differ in anaerobic, aerobic, and sport-specific skill performance. The results of this study demonstrate the need to investigate other performance measures that will help in evaluating the current wheelchair rugby classification system.

Quantification of activity during wheelchair basketball and rugby at the National Veterans Wheelchair Games: A pilot study

To date, no published data exists on distances and speeds traveled by rugby or basketball players during game play. The purpose of this study was to provide quantitative information of selected characteristics of wheelchair basketball and rugby game play. A miniaturized data logger was used to collect the distance traveled, average velocity, activity time, and number of starts and stops during basketball and rugby games. Participants were recruited prior to wheelchair basketball and rugby tournaments during the 2007 and 2008 National Veterans Wheelchair Games. Inclusion criteria were age 18 years or older and been participating in wheelchair basketball or rugby. The wheelchair rugby athletes on average traveled 2364.78 +/- 956.35 meters at 1.33 +/- 0.25 m/sec with 242.61 +/- 80.31 stops and starts in 29.98 +/- 11.79 min of play per game. The wheelchair basketball athletes on average traveled 2679.52 +/- 1103.66 m at 1.48 +/- 0.13 m/sec with 239.78 +/- 60.61 stops and starts in 30.28 +/- 9.59 min of play per game. Previous research has not reported basketball or rugby game play variables such as these, making this data set unique. The information could be used by players and coaches to create training protocols to better prepare for game conditions.

Power output and metabolic cost of synchronous and asynchronous submaximal and peak level hand cycling on a motor driven treadmill in able-bodied male subjects

PURPOSE

To evaluate external power output and physiological responses of synchronous (SYNC) and asynchronous hand cycling (ASYNC) at submaximal and peak levels of exercise.

METHODS

n=9 able-bodied male subjects (age: 20.1+/-2.1 years) performed two (sub)maximal continuous hand cycle exercise tests, using the SYNC and ASYNC mode in a standardized commercial add-on hand cycle unit (counter-balanced order). Treadmill speed (1.89 and 2.17 m s(-1)) and slope (steps of +1%) were changed in a fixed sequence of 3-min exercise steps. Gears were adjusted to 65 rpm. External power output (PO) was continuously monitored with a strain-gauge instrumented chain ring ((SRM) Schoberer Rad Messtechnik). A conventional wheelchair drag test was performed to validate mean external power for each speed-slope combination. Heart rate (HR; bpm) and oxygen uptake (VO2; ml kg(-1) min(-1), SMTP) were continuously monitored. Paired T-tests and ANOVA for repeated measures evaluated effects of mode and exercise level (p<0.05).

RESULTS

Subjects reached peak levels of performance (RER: 1.05+/-0.07 versus 1.10+/-0.1 for SYNC and ASYNC). Peak PO and V(o2) were significantly higher for SYNC (81.6+/-11.8 W versus 68.5+/-10.6 W; 26.4+/-4.5 ml kg(-1) min(-1) versus 21.2+/-3.0 ml kg(-1) min(-1)). At submaximal exercise levels, gross mechanical efficiency (ME) was significantly higher for SYNC (12.1+/-0.9% versus 9.7+/-1.4% at 41 W). No significant differences were found for PO (at equal velocity and slope), as derived from the SRM (SYNC and ASYNC), and from the drag test.

DISCUSSION

The absence of any differences in PO between SYNC and ASYNC, and with respect to the drag test, rules out 'additional external work due to maintain the desired heading' in the ASYNC as an explanation for the lower performance in this mode. Lower peak performance and ME in ASYNC may be explained by the increased stabilizing muscle effort in the upper extremities and trunk in order to combine power production with stable steering. ASYNC is less efficient compared to SYNC. Similarly, peak performance capacity was higher for SYNC.

CONCLUSION

External work does not differ between SYNC and ASYNC hand cycling. SRM readings appear valid for PO monitoring in hand cycling within the studied range of PO. SYNC is more efficient than ASYNC and leads to higher peak performance.