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Objectives: To examine the propensity of tackle height and the number of tacklers that result in head acceleration events (HAEs) in elite-level male and female rugby tackles. Methods: Instrumented mouthguard data were collected from women (n=67) and men (n=72) elite-level rugby players from five elite and three international teams. Peak linear acceleration and peak angular acceleration were extracted from HAEs. Propensities for HAEs at a range of thresholds were calculated as the proportion of tackles/carries that resulted in an HAE exceeding a given magnitude for coded tackle height (low, medium, high) and number of tacklers. Propensity ratios with 95% CIs were calculated for tackle heights and number of tacklers. Results: High tackles had a 32.7 (95% CI=6.89 to 155.02) and 41.2 (95% CI=9.22 to 184.58) propensity ratio to cause ball carrier HAEs>30 g compared with medium tackles for men and women, respectively. Low tackles had a 2.6 (95% CI=1.91 to 3.42) and 5.3 (95% CI=3.28 to 8.53) propensity ratio to cause tackler HAEs>30 g compared with medium tackles for men and women, respectively. In men, multiple tacklers had a higher propensity ratio (6.1; 95% CI=3.71 to 9.93) than singular tacklers to cause ball carrier HAEs>30 g but a lower propensity ratio (0.4; 95% CI=0.29 to 0.56) to cause tackler HAEs>30 g. No significant differences were observed in female tacklers or carriers for singular or multiple tacklers. Conclusion: To limit HAE exposure, rule changes and coaching interventions that promote tacklers aiming for the torso (medium tackle) could be explored, along with changes to multiple tackler events in the male game.
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Player movement in rugby league is complex, being spatiotemporal and multifaceted. Modeling this complexity to provide robust measures of player activity and load has proved difficult, with important aspects of player movement yet to be considered. These include the influence of time-varying covariates on player activity and the combination of different dimensions of player movement. Few studies have simultaneously categorized player activity into different activity states and investigated factors influencing the transition between states, or compared player activity and load profiles between matches and training. This study applied hidden Markov models (HMMs)-a data-driven, multivariate approach-to rugby league training and match GPS data to i) demonstrate how HMMs can combine multiple variables in a data-driven way to effectively categorize player movement states, ii) investigate the influence of two time-varying covariates, score difference and elapsed match time on player activity states, and iii) compare player activity and load profiles within and between training and match modalities. HMMs were fitted to player GPS, accelerometer and heart rate data of one English Super League team across 60 training sessions and 35 matches. Distinct activity states were detected for both matches and training, with transitions between states in matches influenced by score difference and elapsed time and clear differences in activity and load profiles between training and matches. HMMs can model the complexity of player movement to effectively profile player activity and load in rugby league and have the potential to facilitate new research across several sports.
We successfully derived player activity and load profiles in both training and match contexts in a data-driven and multivariate way using hidden Markov models.HMMs can be used to investigate the probability of changing between activity states as a function of time-varying covariates, augmenting current activity profiling practice.We discovered key differences between the activity and load profiles between training and matches in rugby league. In particular, a very directed high-speed running state in training that is seldom accessed by players in matches.We demonstrated how visualizing the output of HMMs can provide decision support by facilitating comparisons of activity and load profiles within and between players in matches and training.We posit that the methodology detailed in this paper can become a standardized approach to player activity and load profiling based on player movement data across multiple sports because it is flexible, data-driven, multivariate and statistically robust.
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Catastrophic cervical spine injuries in rugby often occur during tackling. The underlying mechanisms leading to these injuries remain unclear, with neck hyperflexion and buckling both proposed as the causative factor in the injury prevention literature. The aim of this study was to evaluate the effect of pre-impact head-neck posture on intervertebral neck loads and motions during a head-first rugby tackle. Using a validated, subject-specific musculoskeletal model of a rugby player, and computer simulations driven by in vivo and in vitro data, we examined the dynamic response of the cervical spine under such impact conditions. The simulations demonstrated that the initial head-neck sagittal-plane posture affected intervertebral loads and kinematics, with an extended neck resulting in buckling and supraphysiologic intervertebral shear and flexion loads and motions, typical of bilateral facet dislocation injuries. In contrast, an initially flexed neck increased axial compression forces and flexion angles without exceeding intervertebral physiological limits. These findings provide objective evidence that can inform injury prevention strategies or rugby law changes to improve the safety of the game of rugby.
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Introduction: This article examines athletes preparing for, transitioning into, or going through the developmental stages of a professional sports career, referred to as the emerging athlete career transition. This transition includes events such as selections, Junior-to-Senior promotions, contracting, migration, and early exits. The article presents the collective findings of a multi-case study in three professional sports: rugby league, basketball, and boxing. Method: Consistent with pragmatic qualitative research methodology, a stratified data set was collected and analysed, incorporating researcher-practitioner fieldwork, interviews, documents and artefacts for these cases. This article explores unique events and the demographic and cultural implications of navigating emergent transitions along professional sporting pathways in New Zealand. Findings: These findings highlight the importance of building self-efficacy as a pre-condition for coping through preparation and experience. Recommendations: Recommendations include fostering collaborative cultures and authentic support relationships to facilitate better coping alongside athletic and personal development in these high-pressured environments. Furthermore, understanding existential perspectives of meaning, choice, and responsibility provides insights for developing the resources that allow emerging athletes to thrive in life beyond sport.
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Rugby athletes consume large amounts of animal protein in accordance with conventional dietary guidance to increase muscle mass and strength. This misaligns with national dietary guidelines, which suggest limiting meat consumption for chronic disease prevention. The ability of completely plant-based diets to satisfy the nutritional needs of rugby players has not been explored. This study scaled nutrient data from a large population consuming completely plant-based diets with limited supplemental protein to meet the calorie requirements of adult male rugby athletes to assess whether protein and leucine recommendations for muscular development and athletic performance would be achieved. Calorie requirements were estimated from research that employed the doubly labeled water method, and dietary data from the Adventist Health Study-2 were scaled to this level. The modeled protein level was 1.68 g/kg/day, which meets recommendations for maximal gains in muscle mass, strength, and athletic performance. The modeled leucine level was 2.9 g/meal for four daily meals, which exceeds the threshold proposed to maximally stimulate muscle protein synthesis in young men. These results indicate that consuming large portions of completely plant-based meals can satisfy protein and leucine requirements for maximal muscular development and athletic performance in adult male rugby athletes while aligning with public health recommendations.
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The tackle contest is the most common and most injurious match contact event in rugby and is an indicator of performance. Tackle Ready is World Rugby's tackle technique education program. Limited research has characterized the tackle contest in women's rugby. The purpose of this study is to: (1) identify the match situational characteristics, ball-carrier and tackler technical actions demonstrated in elite women's Rugby Union and (2) to determine the extent to which Tackle Ready recommended tackle techniques were exhibited. Technical characteristics for 1500 tackle events in the 2022-2023 Women's Six Nations Championship were visually assessed according to a predefined coding framework and the Tackle Ready program. Tackles lacked full completion (0.2%) of the 22 coded Tackle Ready techniques with 47% of the recommended techniques demonstrated in each tackle on average (range 15%-98%). A high proportion of tackles involved two defenders (48%), approaching ball-carriers from the side (38%) or oblique angles (39%), in an upright position (30%), and with initial contact made with the arm (51%). Incorrect pre-contact head positioning and head placement upon contact accounted for 50% and 15% of tackles, respectively, and there was a mean of 14 (95% CI 11-18) head and neck contacts to a tackler and 18 (95% CI 14-22) head and neck contacts to a ball-carrier per game. Targeted interventions to encourage adoption of recommended techniques are needed to reduce tackle-related injury risk in women's rugby. This study provides valuable context for future discussion across law enforcement, coach education and gender-specific tackle coaching in the women's game.
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Futebol Americano , Gravação em Vídeo , Humanos , Feminino , Estudos Transversais , Desempenho Atlético/fisiologia , Comportamento CompetitivoRESUMO
Objectives: Tackles making contact above the sternum increase concussion and head injury assessment (HIA) risk in Rugby Union. The sport has introduced harsher sanctions to change tackler behaviours to reduce this risk. This increased high tackle sanction numbers, though it is unknown whether sanction severity is associated with injury risk. Methods: The sanction decision made by match officials for tackles resulting in 157 HIA1 removals, of which 91 were confirmed concussions, was evaluated. The propensity of sanction types, ranging from no foul play to red card, was compared after calculating concussion and HIA1 numbers per 1000 tackles of each sanction, using total tackle number of each sanction type from one season of two elite professional competitions. Results: HIA1 removal and concussion risk increased as sanction severity increased. Red-carded tackles were 271.5 (95% CI 143.8 to 512.6) times more likely to result in concussions than legal tackles. Tacklers and ball carriers were more likely to experience concussions from sanctioned high tackles, with tackler risk 28.5 (95% CI 13.5 to 59.9) times higher for sanctioned high tackles compared with legal tackles, and ball carrier risk elevated 133.7-fold (95% CI 65.5 to 272.8) after sanctioned high tackles. Conclusion: Sanctioned high tackles significantly increase concussion and HIA1 risk to both tacklers and ball carriers. Current decision-making frameworks that guide sanction decisions do identify tackle behaviours that elevate clinical risk. Both tacklers and ball carriers would be less likely to experience concussions and head injuries if the frequency of illegal high tackles is decreased.
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Background: Head-down tackling has been associated with higher rates of head and neck injuries and less successful tackles compared with head-up tackling in American football. In rugby, head and neck injuries have been associated with tackling, with the tackler's head positioned in front of the ball carrier. Purpose: To assess the success and risks of tackling techniques used in the English Rugby Premiership matches. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Three reviewers analyzed 1000 consecutive solo defensive tackling attempts during the 2022 to 2023 season in 6 English Rugby Premiership matches. Slow-motion replays were used to analyze the success of the tackling attempt in terms of head angulation (head up vs head down), head position relative to the offensive player's waist at point of contact, and tackling method (inside shoulder, arm, head across the bow, and head-to-head). The chi-square test or Fisher exact test was used to analyze categorical data, and the 2-tailed Student t test or the Mann-Whitney U test was used to analyze continuous data. Results: The mean interrater reliabilities for analyzing the tackles were good across all groups (κ = 0.715). Head-up and head-down tackling occurred in 848 tackle attempts (84.8%) and 152 tackle attempts (15.2%), respectively. Head-up tackles were successful in 80.7% of the tackle attempts compared with 71.1% of the head-down tackle attempts (P = .0072). Tackles made at or above the waist were successful in 80.7% of the tackle attempts compared with 73.1% of tackles below the waist (P = .0193). The inside-shoulder technique had the highest successful tackle rate at 90.8%, compared with 44.2% with the arm technique (P < .0001) and 72.4% with the head-across-the-bow technique (P < .0001). The inside-shoulder technique resulted in head-up tackling in 84.8% of players compared with 59.8% with the head-across-the-bow technique (P < .0001) and 94.9% with arm tackling (P = .0001). There were 4 recorded injuries to the tackler: 2 neck injuries, 1 shoulder injury, and 1 wrist/hand injury. Conclusion: Head-up tackling, tackles made at or above the level of the offensive player's waist, and inside-shoulder tackling were found to be more efficient in producing successful tackles. The head-down, tackling below the waist, and head-across-the-bow techniques were associated with poor tackling and lower success rates.
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Background: While several clinical factors have independently been linked to anterior cruciate ligament (ACL) injury risk factors, their collective impact on knee loading during the sidestep maneuver is unknown. To better understand these factors, we assessed the relationship between strength, balance, and sprint kinetics and external knee abduction moments during sidestepping on each leg. Methods: Sixteen male academy-level rugby union athletes (age, 20 ± 3 years; body-height, 186 ± 9 cm; body-mass, 99 ± 14 kg) were bilaterally assessed in single-leg: isokinetic concentric and eccentric knee and concentric hip strength, balance at 2 difficulty levels, vertical and horizontal force production during maximal sprinting, and 3-dimensional motion capture while sidestepping on the preferred and non-preferred leg. A hierarchical multiple regression analysis based on this theoretical approach of the mechanics of ACL injury risk was performed. Results: When sidestepping on the preferred leg, larger abduction moments were explained by less concentric hip extension strength and vertical force production during maximal sprinting (R 2 = 41%; ES = 0.64); when sidestepping on the non-preferred leg, larger abduction moments were explained by more concentric hip flexion strength (R 2 = 8%; ES = 0.29). Larger symmetry scores between the legs (representing greater abduction moments) were explained by more horizontal force production during maximal sprinting and less eccentric knee flexion strength (R 2 = 32%; ES = 0.56). Conclusions: Independently, the preferred and non-preferred legs contribute to increased knee abduction moments via unique distributions of strength and/or sprint kinetics. The allocations of strength and sprint kinetics appear interrelated through weaker posterior muscular strength and may be modifiable through a targeted strength training approach.
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BACKGROUND: White matter signal abnormalities have been associated with traumatic brain injury (TBI) and repetitive head impacts (RHI) in contact sports (e.g. American football, rugby). However, previous studies of mixed martial arts (MMA) fighters from the Professional Fighters Brain Health Study have not found greater white matter signal abnormalities in fighters versus controls. OBJECTIVE: This study aims to explore the varying white matter effects of football/rugby and MMA by analyzing how football/rugby history in mixed martial arts fighters may relate to white matter signal abnormalities, helping to further our understanding of sport-specific brain health risks. METHODS: Baseline visits for 90 active, professional, male mixed martial arts fighters and 27 unexposed male controls were cross-sectionally analyzed. Wilcoxon and Kruskal-Wallis tests compared demographics and white matter signal abnormalities, and multivariable regression models examined the associations between football/rugby history and white matter signal abnormality burden in fighters, adjusting for age, education, race, fights, MRI scanner, and supratentorial volume. RESULTS: 37/90 fighters had football/rugby history (mean: 4 years; range: 1-12 years). White matter signal abnormalities were significantly greater in fighters with football/rugby history compared to fighters without football/rugby history (Wilcoxon, p = 0.0190). Football/rugby history was significantly associated with white matter signal abnormality burden >75th percentile (OR: 12, CI: 3.3-61, p < 0.001) and >50th percentile (OR: 3.2, CI: 1.2-9.4, p = 0.024) in fighters. Years of football/rugby were also significantly associated with white matter signal abnormalities. CONCLUSION: Our findings expand on previous literature by demonstrating a significant relationship between white matter signal abnormalities (WMSAs) and football/rugby history but not MMA. Furthermore, our study suggests an added risk for WMSAs in MMA fighters with a history of football/rugby. Future research should further evaluate WMSAs in contact sports, helping to inform athletes, regulatory bodies, and healthcare providers of the potential brain health risks of contact sports.
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Until recently, research examining the application of Rational Emotive Behavior Therapy (REBT) in sports settings was virtually absent in South Africa. Despite the growing evidence of REBT's potential as a psychological intervention in Western nations, its use within the multicultural and sports-fervent context of South Africa remains unexplored. Moreover, limited research has addressed the impact of REBT on rugby players, with only a few case studies being reported. The current experiment employs a cluster randomized trial (CRT) to compare the effects of a 7-week preferential REBT program with a 7-week Mindfulness-Acceptance-Commitment (MAC) program on irrational beliefs, competitive anxiety and subjective performance, among adolescent South African rugby players. We also include a wait-list control group who received neither REBT nor MAC. Results indicate that athletes receiving REBT reported greater improvements in irrational beliefs, anxiety, and subjective performance, while that athletes receiving MAC also reported some improvements in anxiety. This study highlights the potential of REBT as a valuable psychological intervention in the context of South African adolescent rugby players.
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Despite the importance of strength and power in rugby skills and match outcomes, there exists a noticeable gap in the measurement consistency and estimation of a true change of typical assessments designed to assess these qualities. To address this gap, we investigated the between-session reliability, interrelationships, and minimal detectable changes (MDC) of commonly used strength and power measures in team sports. Sixteen national-level rugby 7 s players were tested on two occasions, one week apart. Both the best and average (of 2-3 trials) peak force, peak power, height, distance, and/or strength indices during countermovement jump (CMJ), drop jump (DJ), isometric mid-thigh pull (IMTP), plyometric push-up (PPU), and standing long jump (SLJ) were obtained. Furthermore, one-repetition maximum (1RM) strength for bench press and back squat, reactive strength index, and dynamic strength index were also determined. Reliability was assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV), and used for MDC calculations, and interrelationships between variables were determined using correlation coefficients. Reliability was excellent for bench press, back squat, and SLJ (ICCs > 0.91); high to excellent for IMTP peak force, all CMJ, and DJ (except best DJ height and contact time), and PPU peak force parameters (ICCs > 0.78), with < 10% CVs (except PPU peak power). MDCs were generally smaller for average than best values. Large to very large relationships (r = 0.60 to 0.85) were observed between bench press, back squat, and IMTP with selected parameters of CMJ and PPU (p < 0.05), but not in DJ and SLJ. In conclusion, selected measures of strength and power displayed high to excellent reproducibility, with average values (rather than best) offering more stable assessments, and "smaller" MDCs. Based upon the relationships, it can be inferred that maximising strength would likely contribute to enhanced explosive performance.
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OBJECTIVES: Report two-years of training injury data in senior and academy professional rugby league. DESIGN: Prospective cohort study. METHODS: Match and training time-loss injuries and exposure data were recorded from two-seasons of the European Super League competition. Eleven/12 (2021) and 12/12 (2022) senior and 8/12 (2021) and 12/12 (2022) academy teams participated. Training injuries are described in detail and overall match injuries referred to for comparison only. RESULTS: 224,000 training exposure hours were recorded with 293 injuries at the senior (mean [95â¯% confidence interval]; 3 [2-3] per 1000â¯h) and 268 academy level (2 [2-3] per 1000â¯h), accounting for 31â¯% and 40â¯% of all injuries (i.e., matches and training). The severity of training injuries (senior: 35 [30-39], academy: 36 [30-42] days-lost) was similar to match injuries. Lower-limb injuries had the greatest injury incidence at both levels (senior: 1.85 [1.61-2.12], academy: 1.28 [1.08-1.51] per 1000â¯h). Head injuries at the academy level had greater severity (35 [25-45] vs. 18 [12-14] days-lost; pâ¯<â¯0.01) and burden (17 [16-18] vs. 4 [4-5] days-lost per 1000â¯h; pâ¯=â¯0.02) than senior level. At the senior level, the incidence of contact injuries was lower than non-contact injuries (risk ratio: 0.29 [0.09-0.88], pâ¯=â¯0.02). CONCLUSIONS: Training injuries accounted for about a third of injuries, with similar injury severity to match-play. Within training there is a higher rate of non-contact vs. contact injuries. Whilst current injury prevention interventions target matches, these data highlight the importance of collecting high quality training injury data to develop and evaluate injury prevention strategies in training.
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OBJECTIVES: Explore if implementing an individualised Sub-Symptom Heart Rate Threshold (SSHeRT) rehabilitation program within 48â¯hours versus physical rest for 14â¯days affects recovery following SRC in university-aged student-athletes. DESIGN: Prospective, observational cohort study. METHODS: Two UK university-aged student-athlete rugby union cohorts were compared (Physical Rest Group (PRG), nâ¯=â¯140, July 2019-March 2020 and Controlled Early-Exercise Group (CEG), nâ¯=â¯167, July 2021-April 2023). Both groups completed the test battery (Post-Concussion Symptom Scale (PCSS), Immediate Post-Concussion and Cognitive Test (ImPACT), Vestibular-Ocular Motor Screening Tool (VOMS)) during pre-season to provide a baseline and within 48â¯hours, at 4, 8, 14-days post-SRC and at Return to Play (RTP). The PRG (nâ¯=â¯42) physically rested for 14â¯days as per the nationwide community guidelines. The CEG (nâ¯=â¯52) followed the SSHeRT rehabilitation program. Individual change to baseline was used in all analyses. RESULTS: The CEG performed better on ImPACT's verbal memory at 4 (PRG; -5.5 (-10.8-0.0), CEG; 1.0 (-2.0-10.5), pâ¯=â¯0.05) and 14â¯days (PRG; -2.0 (-10.0-3.0), CEG; 4.0 (-1.0-11.0), pâ¯=â¯0.05) and on the VOMS at 4 (PRG; 3.0 (0.0-12.0), CEG; 0.0 (0.0-5.0), pâ¯=â¯0.03, OR; 2.910) and 14-days post-SRC (PRG; 0.0 (0.0-1.0), CEG; 0.0 (0.0-0.0), OR; 5.914). Near point convergence was better at all time points for the CEG. The CEG was 26.7â¯% more likely to have RTP within 30â¯days, and 6.7 and 5.1 times more likely to have resumed non-contact and contact academic activities by 4â¯days. CONCLUSIONS: SSHeRT is safe, can be used within 48â¯hours of a SRC and may hasten university-aged student-athletes recovery following an SRC.
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Traumatismos em Atletas , Concussão Encefálica , Volta ao Esporte , Humanos , Estudos Prospectivos , Concussão Encefálica/reabilitação , Masculino , Adulto Jovem , Traumatismos em Atletas/reabilitação , Reino Unido , Terapia por Exercício/métodos , Estudantes , Futebol Americano/lesões , Atletas , Fatores de Tempo , Adolescente , Feminino , Frequência Cardíaca , Recuperação de Função FisiológicaRESUMO
Background: The jackling position within rugby has not been previously described as a mechanism for proximal hamstring injuries. Hypothesis: Acute surgical repair of proximal hamstring avulsion injuries sustained from the jackling contact position enables a return to a previous level of sporting activity with low risk of recurrence. Study Design: Case series; Level of evidence, 4. Methods: This study included 54 professional rugby players (mean age, 26 ± 4.8 years) who underwent acute primary surgical repair of complete, proximal hamstring avulsion injuries. The mean follow-up time was 17 months (range, 12-24 months). Mean isometric hamstring strength and function testing was performed at 3 months and 1 year after repair. Results: Of the 54 players, 51 (94.4%) returned to their preinjury level of sporting activity. The mean time from surgical repair to full sporting activity was 7 months (range, 4-12 months). No patients had recurrence of the primary injury. At 1 year postoperatively, patients had significantly restored mean isometric hamstring muscle strength when compared with the uninjured leg at 0° (98.4% ± 2.8%), 15° (95.9% ± 2.9%), and 45° (92.9% ± 4.1%); improved Lower Extremity Functional Score (78.0 ± 2.0); and improved Marx activity rating score (14.3 ± 1.5) (P < .001 for all). Conclusion: Acute surgical repair of proximal hamstring avulsion injuries caused by the contact jackling position produced a high return to preinjury level of sporting activity, increased muscle strength, and improved functional outcome scores, with a low risk of recurrence at short-term follow-up.
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BACKGROUND: Recurrent instability remains a major source of morbidity following arthroscopic Bankart repair. Many risk factors and predictive tools have been described, but there remains a lack of consensus surrounding individual risk factors and their contribution to outcomes. PURPOSE: To systematically review the literature to identify and quantify risk factors for recurrence following arthroscopic Bankart repair. METHODS: A literature search was performed using the PubMed/Medline databases based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Studies were included if they evaluated risk factors for recurrent instability following arthroscopic Bankart repair. RESULTS: Overall, 111 studies were included in the analysis, including a total of 19,307 patients and 2,750 episodes of recurrent instability with 45 risk factors described. Age at operation was reported by 60 studies, with 35 finding increased risk at younger ages. Meta-analysis showed a two-fold recurrence rate of 27.0% (171/634) for patients under 20 years old compared to 13.3% (197/1485) for older patients (p<0.001). Seventeen studies completed multivariable analysis, 13 of which were significant (Odds Ratio 1.3-14.0). Glenoid bone loss was evaluated by 39 studies, with 20 finding an increased risk. Multivariable analysis in 9 studies found OR ranging from 0.7-35.1; 6 were significant. Off-track Hill-Sachs lesions were evaluated in 21 studies (13 significant), with 3 of 4 studies that conducted multivariable analysis finding a significant association with odds ratio of 2.9-8.9 of recurrence. The number of anchors used in repair was reported by 25 studies, with 4 finding increased risk with fewer anchors. Pooled analysis demonstrated a 25.0% (29/156) risk of recurrence with 2 anchors compared to 18.1% (89/491) with 3 or more anchors (p=0.06). Other frequently described risk factors included glenohumeral joint hyperlaxity (46% of studies reporting a significant association), number of preoperative dislocations (31%), contact sport participation (20%), competitive sport participation (46%), patient sex (7%), and concomitant SLAP tear (0%). CONCLUSION: Younger age, glenoid bone loss, and off-track Hill-Sachs lesions, are established risk factors for recurrence following arthroscopic Bankart repair. Other commonly reported risk factors included contact and competitive sports participation, number of fixation devices, and patient sex.
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Researchers have identified kinematic differences between deceptive and non-deceptive rugby reorientation actions. However, the honest and deceptive signals corresponded to 'deception detection' (accuracy increasing) rather than signals that caused deception (accuracy decreasing). In this study, statistical parametric mapping and multilevel modelling were applied to examine the kinematic differences between sidestep and non-deceptive actions during the time window of deception. The analysis compared three-dimensional motion capture data from 144 deceptive actions and 144 genuine actions performed by six high-skilled rugby players. Results indicated that the kinematics of deceptive actions were characterized by a combination of exaggerated head roll, outside foot and centre-of-mass displacement, and attenuated thorax roll and yaw relative to genuine actions. These are candidate sources for the cause of deception, either individually or in combination with other sources. Furthermore, the results indicate that previously identified 'honest' signals may not be reliable sources of information earlier in the action sequence.
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Enganação , Futebol Americano , Humanos , Fenômenos Biomecânicos , Masculino , Adulto Jovem , Futebol Americano/fisiologia , Intenção , Movimento/fisiologia , AdultoRESUMO
Introduction: Initially developed by New Zealand Rugby in 2014, the Blue Card initiative in rugby enables match officials to remove athletes from play if they are suspected to have sustained a concussion. Considerable attention has been paid by sport and health advocates to the possibilities and limitations of this initiative in safeguarding athlete health. However, little if any attention has been paid to the well-being of those responsible for administering the Blue Card (i.e., match officials). The aim of this paper was to examine match officials' experiences with and perspectives on implementing the Blue Card initiative in Ontario, Canada, with focused attention on the tensions around their ability to manage games and participants (e.g., athletes, coaches) while attempting to safeguard athlete well-being. Methods: Using Relational Coordination Theory (RCT) as a guiding framework and qualitative research method, we highlight the rich accounts of 19 match officials' perspectives and experiences regarding sport-related concussion (SRC) management and the Blue Card protocol. Results: Four themes were derived from the data, reflecting latent assumptions embedded within the concussion management process, which include: assumptions of trust, respect, and cooperation; assumptions of shared responsibility; assumptions of shared understanding; and assumptions of harassment-free sport. Discussion: Our findings emphasize the need to attend to social relations in concussion management and provide insight into match officials' fraught experiences on the frontlines of concussion management. We identify factors affecting match official well-being and provide considerations for concussion management initiatives designed to improve athlete safety, such as the Blue Card.
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BACKGROUND: Concussions in Rugby Union are common with an increased risk to adolescent players. Coaches are key to injury prevention and a greater understanding of their knowledge and sentiments may guide future initiatives. There is a lack of data on rugby coaches, especially in South Africa. This study aimed to investigate the knowledge and opinions of high school rugby coaches regarding concussion management. METHODS: This cross-sectional study of 37 high school rugby coaches in South Africa, was conducted via a self-reported questionnaire. Concussion knowledge was scored for correct answers only with closed-question scaling methods to measure the importance of items of concussion management using a graphical rating scale. An attitude scale (Likert) was used to assess self-reported opinions and behaviours. Associations were calculated for participant characteristics and overall concussion injury knowledge. RESULTS: More participants showed good overall knowledge of ≥ 75% (n = 22, 59% vs. n = 15, 40%), especially those with greater coaching experience (p = 0.021). Player welfare was perceived more important than player performance (185 vs. 164), with concussion prevention most important (184 of 185). Appealing characteristics of an injury prevention programme were the improvement of player skill (173, SD ± 0.75, mean 4.68), being adaptable (171, ± 0.86, 4.62), and being completed in the warm-up (167, ± 0.93, 4.51). The biggest perceived barriers were duration (138, ± 1.59, mean 3.73), effort (130, ± 1.56, 3.51), compliance and lack of knowledge (both 127, ± 1.68, 3.43). CONCLUSION: These results support the implementation of ongoing concussion education for rugby coaches and identify areas for promoting awareness and knowledge of concussion injury prevention, identification, and specific management of younger athletes. Appealing characteristics and barriers are highlighted and may allow for improved implementation and adherence to concussion prevention programmes.
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In contact sports such as rugby, players are at risk of sustaining traumatic brain injuries (TBI) due to high-intensity head impacts that generate high linear and rotational accelerations of the head. Previous studies have established a clear link between high-intensity head impacts and brain strains that result in concussions. This study presents a novel approach to investigating the effect of a range of laboratory controlled drop test parameters on regional peak and mean maximum principal strain (MPS) predictions within the brain using a trained convolutional neural network (CNN). The CNN is publicly available at https://github.com/Jilab-biomechanics/CNN-brain-strains . The results of this study corroborate previous findings that impacts to the side of the head result in significantly higher regional MPS than forehead impacts. Forehead impacts tend to result in the lowest region-averaged MPS values for impacts where the surface angle was at 0° and 45°, while side impacts tend to result in higher regional peak and mean MPS. The absence of a neck in drop tests resulted in lower regional peak and mean MPS values. The results indicated that the relationship between drop test parameters and resulting regional peak and mean MPS predictions is complex. The study's findings offer valuable insights into how deep learning models can be used to provide more detailed insights into how drop test conditions impact regional MPS. The novel approach used in this paper to predict brain strains can be applied in the development of better methods to reduce the brain strain resulting from head accelerations such as protective sports headgear.