Tracking of wheelchair rugby players in the 2008 Demolition Derby trial

Age-Related Trajectory and Age at Peak Competitive Performance in Wheelchair Rugby Players at the Paralympic Games

OBJECTIVE

The first objective is to examine the age-related trajectory of competitive performance and the age at peak competitive performance in wheelchair rugby players at the Paralympic Games. Another objective is to verify age correlations with performance over the years for each class.

DESIGN

This is a retrospective cohort study.

RESULTS

Data were collected from the official results books of the Paralympic games. The mean age (SD) of the 267 players and 448 analyzed data from all Paralympic games (from Sidney 2004 to Tokyo 2020) across all classes was 32.8 (6.4) yrs, and the age at peak competitive performance was 30.6 (7.4) yrs. Each class had no statistical difference in age at peak competitive performance. In addition, there was no significant correlation between age and performance within classes or across all Paralympic games.

CONCLUSIONS

The findings indicate that wheelchair rugby players' age at peak competitive performance is 30.6 yrs, which remains consistent across all classes. There is no statistical correlation between age and performance in wheelchair rugby. These findings significantly affect effective talent identification and athlete development programs. This impact ensures that athletes receive the necessary support to reach their maximum potential while avoiding the pitfalls of underestimating or overestimating their stages of development.

Effect of Repeated, On-Field Sprints on Kinematic Variables in Wheelchair Rugby Players

OBJECTIVE

The aim of the study was to evaluate the influence of repeated sprints on kinematic performance and propulsion variables during the acceleration and constant peak velocity phases in wheelchair rugby players classified as defensive (low point in defensive [LP-D]) or offensive players (high point in offensive [HP-O]).

DESIGN

Twenty-two players (13 LP-D and 9 HP-O) performed 6 × 20-m repeated sprint field tests. We calculated peak wheelchair velocities, propulsion phase times, deceleration phase times, cycle times, and left-right velocity asymmetry of the best and last sprints during the acceleration and constant peak velocity phases, the rate of decline in performance variables between the best and the last sprint and a fatigue index.

RESULTS

Peak velocities during the acceleration and constant peak velocity phases and mean velocity over the whole sprint were significantly higher during the best than last sprint. Peak velocities were higher during the acceleration and constant peak velocity phases for the best and last sprint for HP-O. The rate of decline in peak velocity during the constant peak velocity phase was higher for LP-D. Fatigue index and rate of decline in velocities and sprint time were higher for LP-D.

CONCLUSIONS

Performance variables and the rate of decline in performance variables depended on functional capacity and wheelchair type.

Wheelchair rugby players maintain sprint performance but alter propulsion biomechanics after simulated match play

The study aimed to explore the influence of a sports-specific intermittent sprint protocol (ISP) on wheelchair sprint performance and the kinetics and kinematics of sprinting in elite wheelchair rugby (WR) players with and without spinal cord injury (SCI). Fifteen international WR players (age 30.3 ± 5.5 years) performed two 10-s sprints on a dual roller wheelchair ergometer before and immediately after an ISP consisting of four 16-min quarters. Physiological measurements (heart rate, blood lactate concentration, and rating of perceived exertion) were collected. Three-dimensional thorax and bilateral glenohumeral kinematics were quantified. Following the ISP, all physiological parameters significantly increased (p ≤ 0.027), but neither sprinting peak velocity nor distance traveled changed. Players propelled with significantly reduced thorax flexion and peak glenohumeral abduction during both the acceleration (both -5°) and maximal velocity phases (-6° and 8°, respectively) of sprinting post-ISP. Moreover, players exhibited significantly larger mean contact angles (+24°), contact angle asymmetries (+4%), and glenohumeral flexion asymmetries (+10%) during the acceleration phase of sprinting post-ISP. Players displayed greater glenohumeral abduction range of motion (+17°) and asymmetries (+20%) during the maximal velocity phase of sprinting post-ISP. Players with SCI (SCI, n = 7) significantly increased asymmetries in peak power (+6%) and glenohumeral abduction (+15%) during the acceleration phase post-ISP. Our data indicates that despite inducing physiological fatigue resulting from WR match play, players can maintain sprint performance by modifying how they propel their wheelchair. Increased asymmetry post-ISP was notable, which may be specific to impairment type and warrants further investigation.

Current Technologies and Practices to Assess External Training Load in Paralympic Sport: A Systematic Review

CONTEXT

Knowing the methods to assess the external load in Paralympic sports can help multidisciplinary teams rely on scientific evidence to better prescribe and monitor the athlete's development, improving sports performance and reducing the risk of injury/illness of Paralympic athletes.

OBJECTIVES

This review aimed to systematically explore the current practices of quantifying the external load in Paralympic sports and provide an overview of the methods and techniques used.

EVIDENCE ACQUISITION

A search in PubMed, Web of Science, Scopus, and EBSCO was carried out until November 2022. The measures of interest were objective methods for quantifying the external load of training or competition. The inclusion criteria for the studies were as follows: (1) peer-reviewed article; (2) the population were Paralympic athletes; (3) evaluated during training or competition; (4) reported at least one external load measure; and (5) published in English, Portuguese, or Spanish.

EVIDENCE SYNTHESIS

Of the 1961 articles found, 22 were included because they met the criteria, and 8 methods were identified to quantify the external load in training or competition in 8 Paralympic sports. The methods varied according to the characteristics of the Paralympic sports. To date, the devices used included an internal radiofrequency-based tracking system (wheelchair rugby) a miniaturized data logger (wheelchair tennis, basketball, and rugby); a linear position transducer (powerlifting and wheelchair basketball); a camera (swimming, goalball, and wheelchair rugby); a global positioning system (wheelchair tennis); heart rate monitors that assess external load variables in set (paracycling and swimming) and an electronic timer (swimming).

CONCLUSIONS

Different objective methods were identified to assess the external load in Paralympic sports. However, few studies showed the validity and reliability of these methods. Further studies are needed to compare different methods of external load quantification in other Paralympic sports.

Reliability of a Submaximal Field Test in Wheelchair Rugby

The aim was to investigate the test-retest reliability of performance and physiological variables of a submaximal wheelchair rugby field test. Eight trained wheelchair rugby athletes with a spinal cord injury (age: median 40, interquartile range 6.9 y; body mass: median 77.7, interquartile range 23.9 kg) performed a submaximal field test two times with a duration of 41 min, split up into four sets of eight min. Each set included eight laps with one eight-meter sprint (SP8) and one four-meter sprint (SP4). The absolute and relative reliability and the performance decrease (fatigue) across the sets were investigated. The examined variables were sprinting time, heart rate, and RPE. The measured parameters showed moderate (peak heart rate ICC3,1=0.663, peak rate of perceived exertion ICC3,1=0.718), good (SP4 ICC3,1=0.874), and excellent (mean heart rate ICC3,1=0.905, SP8 ICC3,1=0.985) test-retest reliability. Fatigue was observed for SP8 in test 2 between set 2/3 and set 2/4. For test 1 a significant decrease of performance for SP4 was found between set 2/3, set 2/4 and between set 3/4. In conclusion the submaximal field test showed moderate to excellent reliability for all measured parameters. The observed fatigue seems to be not clinically relevant. The test can be recommended to assess the effects of training or interventions.

Load and performance monitoring in wheelchair court sports: A narrative review of the use of technology and practical recommendations

Quantifying measures of physical loading has been an essential part of performance monitoring within elite able-bodied sport, facilitated through advancing innovative technology. In wheelchair court sports (WCS) the inter-individual variability of physical impairments in the athletes increases the necessity for accurate load and performance measurements, while at the same time standard load monitoring methods (e.g. heart-rate) often fail in this group and dedicated WCS performance measurement methods are scarce. The objective of this review was to provide practitioners and researchers with an overview and recommendations to underpin the selection of suitable technologies for a variety of load and performance monitoring purposes specific to WCS. This review explored the different technologies that have been used for load and performance monitoring in WCS. During structured field testing, magnetic switch-based devices, optical encoders and laser systems have all been used to monitor linear aspects of performance. However, movement in WCS is multidirectional, hence accelerations, decelerations and rotational performance and their impact on physiological responses and determination of skill level, is also of interest. Subsequently both for structured field testing as well as match-play and training, inertial measurement units mounted on wheels and frame have emerged as an accurate and practical option for quantifying linear and non-linear movements. In conclusion, each method has its place in load and performance measurement, yet inertial sensors seem most versatile and accurate. However, to add context to load and performance metrics, position-based acquisition devices such as automated image-based processing or local positioning systems are required.Highlights Objective measures of wheelchair mobility performance are paramount in wheelchair court sport support, since they enable quantification of workload across athletes of all classifications and in structured field testing, training and match play settings.Given the variety of methods for load and performance monitoring in wheelchair court sports, this review: identified and examined the technology available; provides meaningful insights and decision guidelines; describes applicability for different goals; and proposes practical recommendations for researchers and sports professionals.Wheelchair mounted inertial sensors are most reliable and versatile for measuring wheelchair mobility performance and estimates of workload, yet a combination with local position measurement via indoor tracking or image-based processing could be useful to add context.For wheelchair athletes bound to a wheelchair for daily use, workload monitoring on a regular basis, both on- and off-court, is crucial to avoid overuse injuries. Alternatively, in athletes with lower severity impairments often lack frequent exposure to optimal and progressive loading, reducing the likelihood of positive physiological adaptations.

Validity of a Wheelchair Rugby Field Test to Simulate Physiological and Thermoregulatory Match Outcomes

The purpose of the study was to verify the criterion-validity (concurrent) of an existing and reliable, submaximal wheelchair Rugby (WCR) field test by examining the correlations of selected measures of physical performance between the field test and real games. Therefore, ten WCR athletes were observed during two WCR real games and during completing the field test two times. Total distance, mean and peak velocity, playing time, number of sprints, sprints per minute, mean and maximal heart rate, body core temperature (Tc), sweat rate, body weight loss, rate of perceived exertion and thermal sensation were measured. Values were correlated with the data observed by completing the field test two times separated by seven days. The results showed significant correlations between games and field tests for sweat rate (r = 0.740, p < 0.001), body weight loss (r = 0.732, p < 0.001) and the increase of Tc (r = 0.611, p = 0.009). All other correlations were not significant. For perceptual responses Bland−Altman analysis showed data within the limits of agreement. Descriptive statistics showed similarity for mean velocity and total distance between tests and games. In conclusion the study provides the first indications that the submaximal field test seems comparable with the game outcomes in terms of increase in Tc, covered distance, mean velocity and perceptual responses. Nevertheless, more research and additional validation are required.

Influence of Wheelchair Type on Kinematic Parameters in Wheelchair Rugby

Introduction

In wheelchair rugby, players use either an offensive or defensive wheelchair depending on their field position and level of impairment. Performance of wheelchair rugby players is related to several parameters, however it is currently unclear if differences in performance are related to wheelchair type or no: the effect of wheelchair type on performance variables has not been evaluated. The aim of this study was to compare offensive and defensive wheelchairs on performance variables during a straight-line sprint.

Methods

Thirteen able-bodied people performed two 20 m sprint trials: one with an offensive and one with a defensive wheelchair. Data were collected using inertial measurement units fixed on the wheelchair. Peak wheelchair velocities and left-right asymmetries in peak wheel velocities were measured during the acceleration and constant peak velocity phases. Sprint time, cycle frequency, and mean and maximum velocity were calculated over the entire sprint.

Results

The peak velocities of the first 2 pushes (acceleration phase) were significantly higher with the defensive than the offensive wheelchair (p &lt; 0.04 and p &lt; 0.02). Mean and maximum sprint velocity were significantly higher (p &lt; 0.03 and p &lt; 0.04, respectively) with the defensive wheelchair. Cycle frequency and asymmetry did not differ between wheelchairs.

Conclusion

Performance was higher with the defensive than the offensive wheelchair, suggesting that the frequent finding that the higher performance of offensive as compared to defensive players is not related to the use of an offensive wheelchair.

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.

Analysis of Physiological and Kinematic Demands of Wheelchair Basketball Games-A Review

Seron, BB, Oliveira de Carvalho, EM, and Greguol, M. Analysis of physiological and kinematic demands of wheelchair basketball games-A review. J Strength Cond Res 33(5): 1453-1462, 2019-In wheelchair basketball (WB), knowledge of the specificities of the game is essential for efficient planning of training strategies for high performance. This study aimed to review the literature concerning studies that have investigated physiological and kinematic measures during WB games. The literature search took place in 4 electronic databases: Scopus, MEDLINE-PubMed, SPORTDiscus, and CINAHL. The inclusion criteria for this review were as follows: (a) articles that evaluated the behavior of physiological and kinematic variables during WB games; (b) athletes aged at least 18 years; and (c) participants with a minimum of 1 year in the modality practice. The selected studies (n = 16) were divided into 2 groups: physiological analysis (n = 11) and kinematic analysis (n = 5). In analyzing the studies, it was observed that the WB game is very demanding in relation to cardiovascular requirements (∼65% of the time is spent in zones of high heart rate [HR] intensity and 70% of V[Combining Dot Above]O2peak). Edwards and Stagno methods seem to be adequate for the control of internal loads imposed on WB players, and moderate correlations were found between rating of perceived exertion measures and HR-based methods. Considering the methodological limitations, kinematic analysis in WB games is rather inconsistent (distance traveled between 2.6 and 5 km; average speed between 1.8 and 2.0 m·s; maximum speed = 4 m·s). Despite the gaps observed in this context, the execution of rotational movements seems to have great relevance for WB. We can conclude that different methods have been adequate for the internal load control in WB games. However, the results of the external demands are not enough to determine a profile nor to serve as parameters for the training prescription for athletes of the modality.

Understanding the Impact of Trunk and Arm Impairments on Wheelchair Rugby Performance During Competition

Purpose: To determine the effect of trunk and arm impairments on physical and technical performance during wheelchair rugby (WR) competition. Methods: Thirty-one highly trained WR players grouped according to their trunk (no trunk [NT]; some trunk [T] function) and arm impairments (poor, moderate, and good arm function) participated in 5 WR matches. Players’ physical (wheelchair mobility) and technical (ball handling) activities were analyzed using an indoor tracking system and video analysis, respectively. Results: Trunk impairment explained some of the variance in physical (10.6–23.5%) and technical (16.2–33.0%) performance. T covered more distance, had more possession, scored more goals, and received and made more passes yet spent less time at low speeds and performed fewer inbounds than NT (≤.05). Arm impairment explained some of the variance in all physical (16.7–47.0%) and the majority of technical (13.1–53.3%) performance measures. Moderate and good arm function covered more distance, reached higher peak speeds, spent more time in higher speed zones, scored more goals, had more possession, and received and made more passes, with a higher percentage of 1-handed and long passes, than poor arm function. Good arm function also received more passes and made a higher percentage of 1-handed passes and defensive blocks than moderate arm function (P ≤ .05). Conclusions: Arm impairment affects a greater number of physical and technical measures of performance specific to WR than trunk impairment during competition. Having active finger function (good arm function) yielded no further improvements in physical performance but positively influenced a small number of technical skills.

Evaluation of Dietary Supplement Use in Wheelchair Rugby Athletes

Wheelchair rugby is a rapidly growing Paralympic sport; however, research remains predominantly in the realms of physiology and biomechanics. Currently, there is little investigation into nutrition and dietary supplement use among wheelchair rugby athletes (WRA). The aim of this study was to assess the types of dietary supplements (DS) used, the prevalence of usage, and the reasons for use among WRA. The secondary aim was to report utilized and preferred sources of nutritional information among this population. A valid, reliable Dietary Supplement Questionnaire was used to report supplement use and reasons for use. Male (n = 33) and female (n = 9) WRA were recruited at a national tournament and through emailing coaches of various Canadian teams. Dietary supplement usage was prevalent as 90.9% of males and 77.8% of females reported usage within the past three months with the most regularly used supplements being vitamin D (26.2%), electrolytes (19.5%), and protein powder (19.5%). The most common reason for usage was performance. The top sources of nutrition information were dietitian/nutritionist and the internet. Further investigation into DS use is needed to help create nutritional guidelines that are accessible to WRA and athletes with disabilities in general.

Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques. Sports Biomech 2018;18:470-481. [PMID: 29578380 DOI: 10.1080/14763141.2018.1433871]

In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

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.

Altering the Speed Profiles of Wheelchair Rugby Players With Game-Simulation Drill Design

PURPOSE

To examine the speed profiles of elite wheelchair rugby (WCR) players during game-simulation training drills of differing player number and shot-clock regulations. A secondary aim was to determine whether the profiles were further influenced by player classification.

METHODS

Eight elite WCR players (low-point n = 3, high-point n = 5) were monitored using a radio-frequency-based indoor tracking system during training sessions over a 5-mo period. Speed profiles were collected for 3 modified game-simulation drills-3-versus-3 drills (n = 8 observations), 30-s shot clock (n = 24 observations), and 15-s shot clock (n = 16 observations)-and were compared with regular game-simulation drills (4 vs 4, 40-s shot clock; n = 16 observations). Measures included mean and peak speed; exercise-intensity ratios, defined as the ratio of time spent performing at high and low speeds; and the number of high-speed activities performed.

RESULTS

Compared with regular game-simulation drills, 3-versus-3 drills elicited a moderate increase in mean speed (6.3%; effect size [ES] = 0.7) and the number of high-speed activities performed (44.1%; ES = 1.1). Minimal changes in speed profiles were observed during the 30-s shot clock, although moderate to large increases in all measures were observed during the 15-s shot-clock drills. Classification-specific differences were further identified, with increased activity observed for high-point players during the 3-versus-3 drill and for low-point players during the 15-s shot clock.

CONCLUSION

By reducing the number of players on court and the shot clock to 15 s, coaches can significantly increase elite WCR players' speed profiles during game-simulation drills.

Neuromuscular Responses and Physiological Changes During Small-Sided Games in Wheelchair Basketball

The aim was to analyze the changes of physical performance and physiological responses during a high-intensity training task in wheelchair basketball (WB) players. Thirteen Spanish first division WB male players participated in this study. A test battery (change of direction ability, sprints, and sled towing) was performed to study neuromuscular responses before (pre) and after (post) the small-sided games (SSG). Furthermore, tympanic temperature and blood lactate concentration were measured before and immediately after players finished the SSG. The SSG tasks consisted in four players against four, 4 bouts of 4 min with 2 min of recovery periods. There was a 1.10% decline in performance in both 5- and 20-m sprints (p < .01; effect size [ES] ≤ 0.14), 1.82% decline in 5-m sled towing (p < .05; ES = 0.18), and 2.68% decline in 20-m sled towing (p < .01; ES = 0.27) between pre- and post-SSG. As in physical performance results, significant differences were observed between pre and post in physiological markers, with increasing tympanic temperature (36.21 ± 0.60 °C to 36.97 ± 0.59 °C; p < .001; ES = 1.27) and blood lactate concentrations (1.95 ± 1.30 mmol/L to 5.84 ± 2.04 mmol/L; p < .001; ES = 2.99) after SSG. The SSG produced a decrease in sprint and sled towing performance after 16 min of intense exercise. Moreover, the decrease in physical performance was accompanied with an increase in physiological responses. These neuromuscular responses could be similar in the real game; thus, coaching staff could benefit from this information when changing bench players.

Load Monitoring Variables in Training and Competition Situations: A Systematic Review Applied to Wheelchair Sports

The aim of this review was to identify the main variables for load monitoring in training and competition situations in wheelchair sports. Studies were identified from a systematic search of three databases (PubMed, Web of Science, and SportDiscuss), with search phrases constructed from MeSH terms, alone or in combination, limited to English-language literature, and published up to January 2016. Our main findings were that variables related to external load (distance, speed, and duration) are used to monitor load in competition. In training situations, researchers have used variables related to internal load (heart rate and VO₂); in both training and competition situations, researchers used internal load measurements (training impulse and ratings of perceived exertion). We conclude that the main variables for load monitoring in competitive situations were distance, speed, and duration, whereas the variables for training situations were heart rate, VO₂, training impulse, and ratings of perceived exertion.

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.

Effect of lower limb compression on blood flow and performance in elite wheelchair rugby athletes

OBJECTIVE

To investigate the effects of compression socks worn during exercise on performance and physiological responses in elite wheelchair rugby athletes.

DESIGN

In a non-blinded randomized crossover design, participants completed two exercise trials (4 × 8 min bouts of submaximal exercise, each finishing with a timed maximal sprint) separated by 24 hr, with or without compression socks.

SETTING

National Sports Training Centre, Queensland, Australia.

PARTICIPANTS

Ten national representative male wheelchair rugby athletes with cervical spinal cord injuries volunteered to participate.

INTERVENTIONS

Participants wore medical grade compression socks on both legs during the exercise task (COMP), and during the control trial no compression was worn (CON).

OUTCOME MEASURES

The efficacy of the compression socks was determined by assessments of limb blood flow, core body temperature, heart rate, and ratings of perceived exertion, perceived thermal strain, and physical performance.

RESULTS

While no significant differences between conditions were observed for maximal sprint time, average lap time was better maintained in COMP compared to CON (P<0.05). Lower limb blood flow increased from pre- to post-exercise by the same magnitude in both conditions (COMP: 2.51 ± 2.34; CON: 2.20 ± 1.85 ml.100 ml.(-1)min(-1)), whereas there was a greater increase in upper limb blood flow pre- to post-exercise in COMP (10.77 ± 8.24 ml.100 ml.(-1)min(-1)) compared to CON (6.21 ± 5.73 ml.100 ml.(-1)min(-1); P < 0.05).

CONCLUSION

These findings indicate that compression socks worn during exercise is an effective intervention for maintaining submaximal performance during wheelchair exercise, and this performance benefit may be associated with an augmentation of upper limb blood flow.

Individualized Internal and External Training Load Relationships in Elite Wheelchair Rugby Players

Aim: The quantification and longitudinal monitoring of athlete training load (TL) provides a scientific explanation for changes in performance and helps manage injury/illness risk. Therefore, accurate and reliable monitoring tools are essential for the optimization of athletic performance. The aim of the present study was to establish the relationship between measures of internal [heart rate (HR) and session RPE (sRPE)] and external TL specific to wheelchair rugby (WR).

Methods: Fourteen international WR athletes (age = 29 ± 7 years; body mass = 58.9 ± 10.9 kg) were monitored during 18 training sessions over a 3 month period during the competitive phase of the season. Activity profiles were collected during each training session using a radio-frequency based indoor tracking system (ITS). External TL was quantified by total distance (m) covered as well as time spent and distance covered in a range of classification-specific arbitrary speed zones. Banister's TRIMP, Edwards's summated HR zone (SHRZ), and Lucia's TRIMP methods were used to quantify physiological internal TL. sRPE was calculated as the product of session duration multiplied by perceived exertion using the Borg CR10 scale. Relationships between external and internal TL were examined using correlation coefficients and the 90% confidence intervals (90% CI).

Results: sRPE (r = 0.59) and all HR-based (r > 0.80) methods showed large and very large relationships with the total distance covered during training sessions, respectively. Large and very large correlations (r = 0.56 − 0.82) were also observed between all measures of internal TL and times spent and distances covered in low and moderate intensity speed zones. HR-based methods showed very large relationships with time (r = 0.71−0.75) and distance (r = 0.70−0.73) in the very high speed zone and a large relationship with the number of high intensity activities (HIA) performed (r = 0.56−0.62). Weaker relationships (r = 0.32−0.35) were observed between sRPE and all measures of high intensity activity. A large variation of individual correlation co-efficient was observed between sRPE and all external TL measures.

Conclusion: The current findings suggest that sRPE and HR-based internal TL measures provide a valid tool for quantifying volume of external TL during WR training but may underestimate HIA. It is recommended that both internal and external TL measures are employed for the monitoring of overall TL during court-based training in elite WR athletes.

Game Performance Evaluation in Male Goalball Players

Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg), body height (cm), the arm span (cm) and length of the body in the defensive position (cm). The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03) and the sum of good defense (p = 0.04). The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04), the sum of penalty defenses (p = 0.01), and fouls (p = 0.01). The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level.

Impact of Wheelchair Rugby on Body Composition of Subjects With Tetraplegia: A Pilot Study

OBJECTIVE

To investigate the longitudinal effects of wheelchair rugby (WR) training on body composition of subjects with tetraplegia.

DESIGN

Subjects were evaluated at baseline and after WR training.

SETTING

Faculty of physical education settings.

PARTICIPANTS

Individuals with tetraplegia (N=13; age, 26.6±6.0y).

INTERVENTIONS

Four sessions per week of WR training composed by aerobic and anaerobic activities and technical and tactical aspects of WR. The average time of intervention was 8.1±2.5 months.

MAIN OUTCOME MEASURES

Body composition assessed by dual-energy x-ray absorptiometry.

RESULTS

After training, fat mass was significantly reduced in the whole body (15,191±4603 vs 13,212±3318 g, P=.016), trunk (7058±2639 vs 5693±1498 g, P=.012), and legs (2847±817 vs 2534±742 g, P=.003). Conversely, increased bone mineral content (183±35 vs 195±32 g, P=.01) and fat-free mass (2991±549 vs 3332±602 g, P=.016) in the arms and reduced bone mineral content in the trunk (553±82 vs 521±86 g, P=.034) were observed after training. Furthermore, no significant correlation between the duration of training and changes in body composition was detected.

CONCLUSIONS

Regular WR training increased lean mass and bone mineral content in the arms and decreased total body fat mass. Conversely, WR training was associated with decreased bone mineral content in the trunk. These results suggest that regular WR training improves body composition in subjects with tetraplegia.

Cooling athletes with a spinal cord injury

Cooling strategies that help prevent a reduction in exercise capacity whilst exercising in the heat have received considerable research interest over the past 3 decades, especially in the lead up to a relatively hot Olympic and Paralympic Games. Progressing into the next Olympic/Paralympic cycle, the host, Rio de Janeiro, could again present an environmental challenge for competing athletes. Despite the interest and vast array of research into cooling strategies for the able-bodied athlete, less is known regarding the application of these cooling strategies in the thermoregulatory impaired spinal cord injured (SCI) athletic population. Individuals with a spinal cord injury (SCI) have a reduced afferent input to the thermoregulatory centre and a loss of both sweating capacity and vasomotor control below the level of the spinal cord lesion. The magnitude of this thermoregulatory impairment is proportional to the level of the lesion. For instance, individuals with high-level lesions (tetraplegia) are at a greater risk of heat illness than individuals with lower-level lesions (paraplegia) at a given exercise intensity. Therefore, cooling strategies may be highly beneficial in this population group, even in moderate ambient conditions (~21 °C). This review was undertaken to examine the scientific literature that addresses the application of cooling strategies in individuals with an SCI. Each method is discussed in regards to the practical issues associated with the method and the potential underlying mechanism. For instance, site-specific cooling would be more suitable for an athlete with an SCI than whole body water immersion, due to the practical difficulties of administering this method in this population group. From the studies reviewed, wearing an ice vest during intermittent sprint exercise has been shown to decrease thermal strain and improve performance. These garments have also been shown to be effective during exercise in the able-bodied. Drawing on additional findings from the able-bodied literature, the combination of methods used prior to and during exercise and/or during rest periods/half-time may increase the effectiveness of a strategy. However, due to the paucity of research involving athletes with an SCI, it is difficult to establish an optimal cooling strategy. Future studies are needed to ensure that research outcomes can be translated into meaningful performance enhancements by investigating cooling strategies under the constraints of actual competition. Cooling strategies that meet the demands of intermittent wheelchair sports need to be identified, with particular attention to the logistics of the sport.

Effect of team rank and player classification on activity profiles of elite wheelchair rugby players

The aim of the current study was to establish which indicators of mobility are associated with successful wheelchair rugby performance and determine whether these indicators differed across classification. Data were collected from 11 international teams during 30 matches (353 match observations) using a radio-frequency-based, indoor tracking system across two tournaments. Players (n = 111) were first grouped by team rank as determined by their International Wheelchair Rugby Federation (IWRF) world ranking (LOW, MID, HIGH) and then into one of four groups based on their IWRF classification: Group I (0.5), Group II (1.0-1.5), Group III (2.0-2.5) and Group IV (3.0-3.5). The volume of activity (relative distance and mean speed), peak speed and time spent within classification-specific arbitrary speed zones were calculated for each individual. Although no differences were identified in the volume of activity, playing time was significantly reduced in LOW (34:51 ± 8:35) compared to MID (48:54 ± 0:51) and HIGH (45:38 ± 9:53), which was further supported by the greater number of substitutions performed by LOW. HIGH achieved greater peak speeds (3.55 ± 0.40 m · s-(1)) than LOW (3.27 ± 0.42 m · s(-1)) and MID (3.45 ± 0.41 m · s(-1)). Peak speed was further shown to be classification-dependent (P ≤ 0.005), whereby HIGH Groups III and IV players achieved greater peak speeds than LOW and MID. The time spent performing high-intensity activities was also greater in HIGH compared to LOW and MID, whilst further influenced by classification (P ≤ 0.0005). To conclude, peak speed and the ability to perform a greater number of high-intensity activities were associated with successful performance in wheelchair rugby.

Activity profiles of elite wheelchair rugby players during competition

PURPOSE

To quantify the activity profiles of elite wheelchair rugby (WCR) players and establish classification-specific arbitrary speed zones. In addition, indicators of fatigue during full matches were explored.

METHODS

Seventy-five elite WCR players from 11 national teams were monitored using a radio-frequency-based, indoor tracking system across 2 international tournaments. Players who participated in complete quarters (n = 75) and full matches (n = 25) were included and grouped by their International Wheelchair Rugby Federation functional classification: groups I (0.5), II (1.0-1.5), III (2.0-2.5), and IV (3.0-3.5).

RESULTS

During a typical quarter, significant increases in total distance (m), relative distance (m/min), and mean speed (m/s) were associated with an increase in classification group (P < .001), with the exception of groups III and IV. However, group IV players achieved significantly higher peak speeds (3.82 ± 0.31 m/s) than groups I (2.99 ± 0.28 m/s), II (3.44 ± 0.26 m/s), and III (3.67 ± 0.32 m/s). Groups I and II differed significantly in match intensity during very-low/low-speed zones and the number of high-intensity activities in comparison with groups III and IV (P < .001). Full-match analysis revealed that activity profiles did not differ significantly between quarters.

CONCLUSIONS

Notable differences in the volume of activity were displayed across the functional classification groups. However, the specific on-court requirements of defensive (I and II) and offensive (III and IV) match roles appeared to influence the intensity of match activities, and consequently training prescription should be structured accordingly.

The validity and reliability of a novel indoor player tracking system for use within wheelchair court sports

The aim of the current study was to investigate the validity and reliability of a radio frequency-based system for accurately tracking athlete movement within wheelchair court sports. Four wheelchair-specific tests were devised to assess the system during (i) static measurements; (ii) incremental fixed speeds; (iii) peak speeds; and (iv) multidirectional movements. During each test, three sampling frequencies (4, 8 and 16 Hz) were compared to a criterion method for distance, mean and peak speeds. Absolute static error remained between 0.19 and 0.32 m across the session. Distance values (test (ii)) showed greatest relative error in 4 Hz tags (1.3%), with significantly lower errors seen in higher frequency tags (<1.0%). Relative peak speed errors of <2.0% (test (iii)) were revealed across all sampling frequencies in relation to the criterion (4.00 ± 0.09 m · s-(1)). Results showed 8 and 16 Hz sampling frequencies displayed the closest-to-criterion values, whilst intra-tag reliability never exceeded 2.0% coefficient of variation (% CV) during peak speed detection. Minimal relative distance errors (<0.2%) were also seen across sampling frequencies (test (iv)). To conclude, the indoor tracking system is deemed an acceptable tool for tracking wheelchair court match play using a tag frequency of 8 or 16 Hz.

Comparing the activity profiles of wheelchair rugby using a miniaturised data logger and radio-frequency tracking system

The current study assessed the validity and reliability of a miniaturised data logger (MDL) against a radio-frequency-based indoor tracking system (ITS) for quantifying key aspects of mobility performance during wheelchair rugby. Eleven international wheelchair rugby players were monitored by both devices during four wheelchair rugby matches. MDL data were averaged over both 1-second (MDL-1) and 5-second (MDL-5) intervals to calculate distance, mean, and peak speeds. The results revealed no significant differences between devices for the distance covered or mean speeds, although random errors of 10% and 12%, respectively, were identified in relation to the mean values. No significant differences in peak speed were revealed between ITS (3.91 ± 0.32 m·s⁻¹) and MDL-1 (3.85 ± 0.45 m·s⁻¹). Whereas peak speeds in MDL-5 (2.75 ± 0.29 m·s⁻¹) were significantly lower than ITS. Errors in peak speed led to large random errors in time and distance spent in speed zones relative to peak speed, especially in MDL-5. The current study revealed that MDL provide a reasonable representation of the distance and mean speed reported during wheelchair rugby. However, inaccuracy in the detection of peak speeds limits its use for monitoring performance and prescribing wheelchair rugby training programmes.

Validity and Reliability of an Inertial Sensor for Wheelchair Court Sports Performance

The purpose of the current study was to determine the validity and reliability of an inertial sensor for assessing speed specific to athletes competing in the wheelchair court sports (basketball, rugby, and tennis). A wireless inertial sensor was attached to the axle of a sports wheelchair. Over two separate sessions, the sensor was tested across a range of treadmill speeds reflective of the court sports (1.0 to 6.0 m/s). At each test speed, ten 10-second trials were recorded and were compared with the treadmill (criterion). A further session explored the dynamic validity and reliability of the sensor during a sprinting task on a wheelchair ergometer compared with high-speed video (criterion). During session one, the sensor marginally overestimated speed, whereas during session two these speeds were underestimated slightly. However, systematic bias and absolute random errors never exceeded 0.058 m/s and 0.086 m/s, respectively, across both sessions. The sensor was also shown to be a reliable device with coefficients of variation (% CV) never exceeding 0.9 at any speed. During maximal sprinting, the sensor also provided a valid representation of the peak speeds reached (1.6% CV). Slight random errors in timing led to larger random errors in the detection of deceleration values. The results of this investigation have demonstrated that an inertial sensor developed for sports wheelchair applications provided a valid and reliable assessment of the speeds typically experienced by wheelchair athletes. As such, this device will be a valuable monitoring tool for assessing aspects of linear wheelchair performance.

Performance analysis of elite men's and women's wheelchair basketball teams

The purpose of the present study was to identify which game-related statistics discriminate winning and losing teams in men's and women's elite wheelchair basketball. The sample comprised all the games played during the Beijing Paralympics 2008 and the World Wheelchair Basketball Championship 2010. The game-related statistics from the official box scores were gathered and data were analysed in 2 groups: balanced games (final score differences ≤ 12 points) and unbalanced games (final score differences >13 points). Discriminant analysis allowed identifying the successful 2-point field-goals and free-throws, the unsuccessful 3-point field-goals and free-throws, the assists and fouls received as discriminant statistics between winning and losing teams in men's balanced games. In women's games, the teams were discriminated only by the successful 2-point field-goals. Linear regression analysis showed that the quality of opposition had great effects in final point differential. The field-goals percentage and free-throws rate were the most important factors in men's games, and field-goals percentage and offensive rebounding percentage in women's games. The identified trends allow improving game understanding and helping wheelchair basketball coaches to plan accurate practice sessions and, ultimately, deciding better in competition.

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.

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.

Paralympic sport: an emerging area for research and consultancy in sports biomechanics

The Paralympic Games are the pinnacle of sport for many athletes with a disability. The overall purpose of this paper is to highlight the role that the field of sports biomechanics specifically (and sports science in general) may play in improving performance in various summer Paralympic sports through research and consultancy. To achieve this broad aim, this review provides some history and background on the Summer Paralympic Games, discusses the eligibility and classification rules, describes the potential for the constraints-led approach of dynamical systems theory to inform practice and research in this area, and reviews selected studies examining the biomechanics of the primary forms of Paralympic locomotion. Some recommendations on how sports biomechanics can help facilitate improvements in Paralympic athletic performance through applied research and consultancy are provided, along with commentary on what may be some of the most important issues addressing Paralympic sport.