Synergistic patterns during steady-state wheelchair propulsion in male wheelchair rugby players with cervical spinal cord injury: influence of functional classification and competitive level.

The classification systems used in wheelchair sport are based primarily upon sensory and motor ability. We asked whether the classification systems are also related to respiratory function at baseline and during exercise. Purpose: To investigate the relationship between functional class and respiratory function in GB Paralympic wheelchair basketball and rugby players. Methods: 11 wheelchair basketball and 15 wheelchair rugby players were classified using the IWBF (2004) and IWRF (2006) systems, respectively. Pulmonary function (spirometry) and respiratory muscle strength (mouth pressures) were assessed at rest. Additionally, for 11 wheelchair rugby players, ventilation and pulmonary gas exchange were assessed during maximal incremental arm-cranking exercise. Results: For wheelchair basketball, there were significant (P < 0.01) correlations for functional class vs. pulmonary function (% predicted FEV1, r = 0.76; % predicted FVC, r = 0.78). For wheelchair rugby, there were also significant (P < 0.05) correlations for functional class vs. pulmonary function (% predicted FEV1, r = 0.63; % predicted FVC, r = 0.64). For the wheelchair rugby players assessed during exercise, there were significant (P < 0.05) correlations for functional class vs. peak exercise responses (VO2/kg, r = 0.66; VE, r = 0.62; VT, r = 0.75). Conclusion: Based on selected measures of respiratory function, IWBF and IWRF classification systems group athletes into the appropriate functional class.

Manual wheelchair (MWC) propulsion relies on upper limb power, coordination, and endurance. Propulsion asymmetry can reduce efficiency, yet the impact of fatigability on upper limb asymmetry remains underexplored. This study aimed to compare propulsion performance and asymmetry between wheelchair basketball (WB) and wheelchair rugby (WR) players and assess the effect of fatigability on asymmetry during repeated sprints. 13 WB and 10 WR players from French national teams performed 6 × 20 m sprints with 20-second recovery intervals. Inertial measurement units (IMUs) were placed on wheel spokes and the trunk captured wheel velocity and trunk motion. The Instantaneous Symmetry Index (ISI) quantified propulsion asymmetry. Both groups showed performance decline across sprints, with WB players experiencing a drop in maximal power output and WR players showing reduced average sprint velocity. Asymmetry was highest at sprint initiation, with WB players exhibiting greater ISI values than WR players. Interestingly, WR players demonstrated reduced asymmetry at sprint onset, possibly due to sport-specific anthropometric adaptations. Trunk motion remained stable over sprints but was more pronounced in WB players. The results highlight distinct fatigue-related adaptations in propulsion asymmetry between WB and WR players. The study's findings underscore the need for further exploration into the nuanced dynamics of propulsion and asymmetry in parasport performance.

Wheelchair rugby is a contact sport in which falls are common and injury rates are high, yet the characteristics of the falls are still under-reported. We investigated the fall characteristics of men's wheelchair rugby players by functional classification, using all 36 official match videos from the Rio 2016 and Tokyo 2020 summer Paralympic Games. The videos were analyzed to evaluate the number of falls, playing time when the fall occurred, playing phase (offense or defense), contact with other players, foul judgement, direction of the fall, and the body part first in contact with the floor. All 182 men's wheelchair rugby players (Rio 2016, 94; Tokyo 2020, 88) were classified as low-point players or high-point players depending on their functional classification. A total of 200 falls were detected, 27 (13.5%) for low-point players and 173 (86.5%) for high-point players. Significant differences were noted between low-point players and high-point players in the direction of the fall and body part first in contact with the floor. High-point players had more falls in the forward and left-right directions, whereas low-point players were characterized by a higher percentage of falls in the left-right and backward directions. Additionally, high-point players landed on the floor with their hands with high frequency, whereas low-point players landed with their elbows and shoulders more often. Our findings suggest the significance of devising measures to prevent falls during men's wheelchair rugby games according to their functional classification.

To compare the effects of typical competition versus high-intensity intermittent warm-up (WU) on thermoregulatory responses and repeated sprint performance during wheelchair rugby game play. An intermittent sprint protocol (ISP) simulating the demands of wheelchair rugby was performed by male wheelchair rugby players (7 with cervical spinal cord injury [SCI] and 8 without SCI) following 2 WU protocols. These included a typical competition WU (control) and a WU consisting of high-intensity efforts (INT). Core temperature (Tcore), thermal sensation, and thermal comfort were recorded. Wheelchair performance variables associated to power, speed, and fatigue were also calculated. During the WU, Tcore was similar between conditions for both groups. During the ISP, a higher Tcore was found for SCI compared to NON-SCI (38.1 [0.3] vs 37.7 [0.3] °C: P = .036, d = 0.75), and the SCI group experienced a higher peak Tcore for INT compared with control (39.0 [0.4] vs 38.6 [0.6] °C; P = .004). Peak Tcore occurred later in the ISP for players with SCI (96 [5.8] vs 48 [2.7]min; P < .001). All players reported a higher thermal sensation and thermal comfort following INT (P < .001), with no differences between conditions throughout the ISP. No significant differences were found in wheelchair performance variables during the ISP between conditions (P ≥ .143). The high-INT WU increased thermal strain in the SCI group during the ISP, potentially due to increased metabolic heat production and impaired thermoregulation, while not impacting on repeated sprint performance. It may be advisable to limit high-INT bouts during a WU in players with SCI to mitigate issues related to hyperthermia in subsequent performance.

Quality of life (QOL) of persons with disabilities has recently become focus of studies in various academic disciplines There is 250-500 thousands new cases of spinal cord injury annually, with majority being caused by accidents. Spinal cord injury (SCI) makes significant impact on person's lives as only one third of persons with SCI are able to return to jobs they did prior to acquiring SCI and majority of them cannot return to the hobbies or sports. The purpose of this study was to show the effect of sport participation in wheelchair rugby on QOL of persons with spinal cord injury. Twenty male wheelchair rugby players - athletes with tetraplegia, who are engages in regular organized physical activity - wheelchair rugby training and competition (mean age = 32.50, SD = 8.46). Sixteen persons with tetraplegia (all males) who were not actively engaging in sports - not participating in an organized physical activity (mean age = 39.44, SD = 7.44). While results of wheelchair rugby players were higher in all four domains of QOL, the only significant difference was found in domain one focusing on perceived physical health.

A cross-sectional study with comparison group. To evaluate the effects of long-term wheelchair rugby (WR) training on lipid profile, blood antioxidant status and the brain-derived neurotrophic factor (BDNF) level. Academy of Physical Education, Katowice, Poland. Thirty-two males with chronic cervical spinal cord injury (SCI) assigned into the physically active 'low-point' (LP, n=15) or 'high-point' (HP, n=8) WR players groups and the sedentary manual wheelchair users (SED, n=9) participated in this study. Fasting blood samples were collected at rest for assessment of activities of antioxidant enzymes, concentrations of reduced glutathione, uric acid, malondialdehyde (MDA), lipid profile measures and BDNF. No significant differences were found in anthropometric measures and serum lipid profile indices, although a slight tendency toward higher high-density lipoprotein cholesterol level was evidenced in WR players. Significantly lower serum malondialdehyde (MDA) and significantly higher levels of the overall enzymatic antioxidant potential index (EAP) in WR players, compared with SED, may reflect some WR training-induced increase in the blood's antioxidant capacity. There was also a slight tendency toward higher serum BDNF level in WR players compared with the SED group and a significant positive association between years of WR training and the BDNF level. A voluntary participation in a long-term WR training program has several health promoting outcomes for individuals with chronic SCI. Among the most important are enhancement of the blood antioxidant defense capacity evidenced by lower MDA and higher EAP levels, as well as WR training-induced activation of BDNF signaling.

Prediction of propulsion kinematics and performance in wheelchair sports has the potential to improve capabilities of individual wheelchair prescription while minimizing testing requirements. While propulsion predictions have been developed for daily propulsion, these have not been extended for maximal effort in wheelchair sports. A two step-approach to predicting the effects of changing set-up in wheelchair rugby was developed, consisting of: (One) predicting propulsion kinematics during a 5 m sprint by adapting an existing linkage model; and (Two) applying partial least-squares regression to wheelchair set-up, propulsion kinematics, and performance. Eight elite wheelchair rugby players completed 5 m sprints in nine wheelchair set-ups while varying seat height, seat depth, seat angle, and tire pressure. Propulsion kinematics (contact and release angles) and performance (sprint time) were measured during each sprint and used for training and assessment for both models. Results were assessed through comparison of predicted and experimental propulsion kinematics (degree differences) for Step One and performance times (seconds differences) for Step Two. Kinematic measures, in particular contact angles, were identified with mean prediction errors less than 5 degrees for 43 of 48 predictions. Performance predictions were found to reflect on-court trends for some players, while others showed weaker prediction accuracy. More detailed modeling approaches that can account for individual athlete activity limitations would likely result in improved accuracy in propulsion and performance predictions across a range of wheelchair sports. Although this would come at an increased cost, developments would provide opportunities for more suitable set-ups earlier in an athlete's career, increasing performance and reducing injury risk.

Mechanisms of improved exercise capacity following respiratory muscle training in athletes with cervical spinal cord injury.

Perceived exertion responses to wheelchair propulsion differ between novice able-bodied and trained wheelchair sportspeople

Blood sodium concentration of tetraplegics during exercise has not been investigated. This study aimed to measure blood sodium changes in relation to fluid intakes and thermal comfort in tetraplegics during wheelchair rugby training. Twelve international male wheelchair rugby players volunteered, and measures were taken during 2 training sessions. Body mass, blood sodium concentration, and subjective thermal comfort using a 10-point scale were recorded before and after both training sessions. Fluid intake and the distance covered were measured during both sessions. The mean (SD) percentage changes in body mass during the morning and afternoon training sessions were +0.4%1 (0.65%) and +0.69% (1.24%), respectively. There was a tendency for fluid intake rate to be correlated with the percentage change in blood sodium concentration (p = .072, r2 = .642) during the morning training session; this correlation reached significance during the afternoon session (p = .004, r2 = .717). Fluid intake was significantly correlated to change in thermal comfort in the morning session (p = .018, r2 = .533), with this correlation showing a tendency in the afternoon session (p = .066, r2 = .151). This is the first study to investigate blood sodium concentrations in a group of tetraplegics. Over the day, blood sodium concentrations significantly declined; 2 players recorded blood sodium concentrations of 135 mmol/L, and 5 recorded blood sodium concentrations of 136 mmol/L. Excessive fluid intake as a means of attenuating thermal discomfort seems to be the primary cause of low blood sodium concentrations in tetraplegic athletes. Findings from this study could aid in the design of fluid-intake strategies for tetraplegics.

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.

Objective: CSCI-related dysfunction frequently determines and generates other deficits and disorders. The aim of this study was to assess the accuracy of BAI, when compared to BMI in wheelchair rugby players after cervical spinal cord injury. Methods: The study group consisted of 14 Caucasian males competing in wheelchair rugby players, aged 25-40 years (32.6 ± 5.1 years), who had sustained CSCI. All subjects were measured for body height, waist and hip circumference in centimeters, while body mass was expressed in kilograms. Body fat content was measured with the use of Viscan Tanita AB-140 utilize BIA. The existence of significant bivariate correlations among variables such as BAI, BMI, height, weight, hip circumference and % visceral fat and trunk fat determined by BIA was ascertained by means of determining Pearson correlation coefficients. Results: BMI calculated according to the standards of the general population indicated that 80% of participants fell within the norm (BMI 25 kg/m 2 and BAI >21%, significant relationships were observed between BAI and the following indicators WC (r=0.9), % TF (r=0.9), % VF (r=0.8), WHR (r=0.8). Such a trend was not observed for BMI. Conclusions: The BAI can be considered a good tool for evaluating adiposity in patients with spinal cord injury. BAI is very specific and sensitive.

Background: The positive effects of caffeine supplementation on strength-power and endurance performance in healthy athletes have been demonstrated in many studies. A possible mechanism for its ergogenic effect relates to its influence on the central nervous system. Post-traumatic complications in cervical spinal cord injury affect almost all body systems including the nervous system. For this reason, we expect that caffeine will have a different effect of performance in the group of athletes with spinal cord injuries. Objective: To examine the effects of caffeine supplementation on maximal aerobic power in elite wheelchair rugby players. Methods: Seven elite male wheelchair rugby players with complete cervical-level SCI (C4-Th1) were recruited (mean age: 28 ± 5.42 years; mean body mass index: 26 ± 2.84 kg/m2). The effect of caffeine was assessed by an incremental arm ergometer test until volitional exhaustion. The maximal oxygen uptake (VO2max/kg), maximum power (W max/kg), peak heart rate (HR peak), and intensity of perceived exertion (RPE) were measured. Participants performed the test twice with a two-week washout period. One hour before each exercise test subjects ingested a capsule of placebo or caffeine (3 mg per kg of body weight). The tests were applied in a double-blind, randomized, repeated-measures, and cross-over design. Wheelchair rugby players were chosen because of the expected high homogeneity of participants - in terms of the type and degree of disability, gender, and age of the players. Results: The monitored parameters were not significantly influenced by caffeine intervention as compared to placebo: VO2max/kg (p = .40), W max/kg (p = .34), HR peak (p = .50) and RPE (p = .50). Conclusions: The current findings suggest that a caffeine dose of 3 mg/kg body mass does not improve oxygen uptake and maximal power in elite wheelchair rugby players.

Introduction: Wheelchair sports, such as wheelchair rugby (WR), are intermittent in nature, combining high- and low-intensity actions. Although some data exists on the effects of caffeine intake in WR players, further research using specific physical tests related to the demands of WR gameplay is necessary. Aims: The aim of this study was to analyze the acute effect of caffeine supplementation on neuromuscular performance and repeated-sprint ability (RSA) in WR players. Methodology: A total of four WR players participated in this study. Participants ingested 4 mg/kg of anhydrous caffeine dissolved with saccharin in 200 mL of water (CAF) and 200 mL of plain water with saccharin (PLA) 45 minutes before warming up. The following tests were performed: rotator cuff maximum voluntary isometric contraction (MVIC) test, initial maximum push-rim propulsion (IMPRP) test, 10-m sprint test and RSA test (12 x 5 m). Results: CAF resulted in increased strength and power values in the MVIC and IMPRP tests (≈14.0–18.0%). Also, the CAF group reported a shorter sprint time at 3 (≈5.0%), 5 (≈3.0%), and 10 meters (≈2.0%). Discussion: Improvements in distance in the IMPRP as well as in a 20m sprint test have previously been reported in WR players after ingesting 4 mg/kg caffeine. Conclusions: The intake of 4 mg/kg of caffeine 45 minutes before warming up could be slightly enhance performance, especially in neuromuscular actions, in WR players.

Bilateral scapular kinematics, asymmetries and shoulder pain in wheelchair athletes