A global perspective on collision and non-collision match characteristics in male rugby union: Comparisons by age and playing standard.

This study quantified and compared the collision and non-collision match characteristics across age categories (i.e. U12, U14, U16, U18, Senior) for both amateur and elite playing standards from Tier 1 rugby union nations (i.e. England, South Africa, New Zealand). Two-hundred and one male matches (5911 min ball-in-play) were coded using computerised notational analysis, including 193,708 match characteristics (e.g. 83,688 collisions, 33,052 tackles, 13,299 rucks, 1006 mauls, 2681 scrums, 2923 lineouts, 44,879 passes, 5568 kicks). Generalised linear mixed models with post-hoc comparisons and cluster analysis compared the match characteristics by age category and playing standard. Overall significant differences (p < 0.001) between age category and playing standard were found for the frequency of match characteristics, and tackle and ruck activity. The frequency of characteristics increased with age category and playing standard except for scrums and tries that were the lowest at the senior level. For the tackle, the percentage of successful tackles, frequency of active shoulder, sequential and simultaneous tackles increased with age and playing standard. For ruck activity, the number of attackers and defenders were lower in U18 and senior than younger age categories. Cluster analysis demonstrated clear differences in all and collision match characteristics and activity by age category and playing standard. These findings provide the most comprehensive quantification and comparison of collision and non-collision activity in rugby union demonstrating increased frequency and type of collision activity with increasing age and playing standard. These findings have implications for policy to ensure the safe development of rugby union players throughout the world.

The safety of rugby union, especially the tackle, has previously been questioned but limited data are available to understand the collision and non-collision match characteristics between different age categories and playing standards.The frequency of collision and non-collision match characteristics increase with age and playing standard except for the frequency of scrums and tries which are lowest at the Senior Elite level. The activity of the tackle and ruck are also different between age categories and playing standards.Hierarchical cluster analysis demonstrated clear differences in all and collision match characteristics between junior (i.e. U12, U14, U16), and amateur (i.e. U18 and senior) and elite (i.e. U18 and senior) playing levels.Governing bodies and practitioners should be aware of the differences in collision and non-collision match characteristics by age and playing standard, when reviewing future versions of rugby union.

Video-based technical feedback and instruction improves tackling technique of community rugby union players.

The aims of this study were to test the change and retention of player's overall tackling technique and technical components following a player-specific video-based technical feedback and instruction intervention on both their dominant and non-dominant shoulders. Twenty-four (n = 24) rugby union players participated in a non-randomized control-intervention, which consisted of a video-based technical feedback and instruction group (video-based technical feedback) and a no video-based technical feedback and instruction group (control). During 3 sessions (baseline, intervention, retention) separated by one week, participants in each group performed six tackles (3 tackles on each shoulder) on a tackle simulator. In total, 432 tackles (video-based technical feedback = 216, control = 216) were analysed. Each tackle was analysed using a standardized list of technical criteria (arbitrary units, AU). For the dominant shoulder, tackling technique scores significantly improved from baseline to intervention for both groups. For the non-dominant shoulder, only the video-based technical feedback group improved their tackling technique from baseline to intervention (baseline 6.89 [6.33-7.45] AU vs. intervention 7.72 [7.35-8.10] AU p = .001, ES = 0.60 moderate). For the retention session, the video-based technical feedback group scored significantly higher than the control group, for dominant (video-based technical feedback 8.00 [7.60-8.40] AU vs. control 7.22 [6.83-7.62] AU p = .014, ES = 0.66 moderate) and non-dominant (video-based technical feedback 8.11 [7.81-8.41] AU vs. control 7.22 [6.90-7.55] p = .004, ES = 0.96 moderate) tackles. This study demonstrates the efficacy of video-based technical feedback as a method to optimize tackle training for player safety and performance.HIGHLIGHTSVideo-based technical feedback can improve tackling technique in both dominant and non-dominant shoulders.Video-based technical feedback group continued to improve following a retention interval of one week.The video-based technical feedback group showed a significant (with a moderate effect size) improvement from baseline for two techniques - namely, "body position - upright to low" and "drive through contact with legs and shoulders".Video-based technical feedback can be used as a method to optimize tackle training for injury prevention and performance.

Tackle Technique and Changes in Playerload™ During a Simulated Tackle: An Exploratory Study.

In collision sports, the tackle has the highest injury incidence, and is key to a successful performance. Although the contact load of players has been measured using microtechnology, this has not been related to tackle technique. The aim of this study was to explore how PlayerLoad™ changes between different levels of tackling technique during a simulated tackle. Nineteen rugby union players performed twelve tackles on a tackle contact simulator (n = 228 tackles). Each tackle was recorded with a video-camera and each player wore a Catapult OptimEyeS5. Tackles were analysed using tackler proficiency criteria and split into three categories: Low scoring(≤5 Arbitrary units (AU), medium scoring(6 and 7AU) and high scoring tackles(≥8AU). High scoring tackles recorded a higher PlayerLoad™ at tackle completion. The PlayerLoad™ trace was also less variable in the high scoring tackles. The variability in the PlayerLoad™ trace may be a consequence of players not shortening their steps before contact. This reduced their ability to control their movement during the contact and post-contact phase of the tackle and increased the variability. Using the PlayerLoad™ trace in conjunction with subjective technique assessments offers coaches and practitioners insight into the physical-technical relationship of each tackle to optimise tackle skill training and match preparation.

A Masterclass on developing clinical tools in sport and exercise medicine using principles of clinimetrics.

Musculoskeletal assessment and skill screening tests are regularly used in sports and exercise science to determine performance levels or injury risk in athletes. Many of these tests are used without having undergone clinimetric evaluation. The steps to develop these screening tests and assessment tools should include a structured process according to the clinimetric principles (conceptual and measurement model, reliability, validity, responsiveness, interpretability, burden, alternative forms, and cultural and language adaptation). This systematic process ensures the test measures what it intends to measure and also quantifies the error around the measurement. In this Masterclass we discuss the systematic development and clinimetric evaluation of clinical and performance tests used in sports and exercise science. We use the sport of mountain biking to provide a contextual example of how these principles may be practically applied.

Quantifying Collision Frequency and Intensity in Rugby Union and Rugby Sevens: A Systematic Review.

BACKGROUND: Collisions in rugby union and sevens have a high injury incidence and burden, and are also associated with player and team performance. Understanding the frequency and intensity of these collisions is therefore important for coaches and practitioners to adequately prepare players for competition. The aim of this review is to synthesise the current literature to provide a summary of the collision frequencies and intensities for rugby union and rugby sevens based on video-based analysis and microtechnology. METHODS: A systematic search using key words was done on four different databases from 1 January 1990 to 1 September 2021 (PubMed, Scopus, SPORTDiscus and Web of Science). RESULTS: Seventy-three studies were included in the final review, with fifty-eight studies focusing on rugby union, while fifteen studies explored rugby sevens. Of the included studies, four focused on training-three in rugby union and one in sevens, two focused on both training and match-play in rugby union and one in rugby sevens, while the remaining sixty-six studies explored collisions from match-play. The studies included, provincial, national, international, professional, experienced, novice and collegiate players. Most of the studies used video-based analysis (n = 37) to quantify collisions. In rugby union, on average a total of 22.0 (19.0-25.0) scrums, 116.2 (62.7-169.7) rucks, and 156.1 (121.2-191.0) tackles occur per match. In sevens, on average 1.8 (1.7-2.0) scrums, 4.8 (0-11.8) rucks and 14.1 (0-32.8) tackles occur per match. CONCLUSIONS: This review showed more studies quantified collisions in matches compared to training. To ensure athletes are adequately prepared for match collision loads, training should be prescribed to meet the match demands. Per minute, rugby sevens players perform more tackles and ball carries into contact than rugby union players and forwards experienced more impacts and tackles than backs. Forwards also perform more very heavy impacts and severe impacts than backs in rugby union. To improve the relationship between matches and training, integrating both video-based analysis and microtechnology is recommended. The frequency and intensity of collisions in training and matches may lead to adaptations for a "collision-fit" player and lend itself to general training principles such as periodisation for optimum collision adaptation. Trial Registration PROSPERO registration number: CRD42020191112.

Accessing healthcare as a person with a rugby-related spinal cord injury in South Africa: the injured player's perspective.

BACKGROUND: Rugby carries a risk for serious injuries, including acute spinal cord injuries. The lifetime health consequences of these injuries may be far-reaching. PURPOSE: In this study, we aimed to describe barriers and facilitators to healthcare and rehabilitation, in individuals with rugby-related spinal cord injuries in South Africa. METHODS: This study adopted a pragmatic qualitative approach. Stratified purposive sampling was used to select interviews from players from a variety of socio-economic status and geographical areas for inclusion in this study. The final sample consisted of thirty-one (n = 31) participants. Thematic analysis was used to analyze the data. RESULTS: Participants described long-term, accessible, affordable, quality healthcare and rehabilitation as important contributors to their quality of life. Even though public healthcare is accessible from a cost point of view, quality of care, availability of rehabilitation services and factors such as affordability and availability of adequate transport remain a barrier for lower socio-economic groups. CONCLUSION: This population was unique, as the support from a dedicated organization enabled participants to overcome some barriers, highlighting the challenges of the healthcare system in maintaining the health of people with spinal cord injuries. Every effort should be made to create equitable access to healthcare and rehabilitation for persons with spinal cord injuries in South Africa.

A descriptive prospective study of sports medicine practices for athletes in Uganda.

BACKGROUND: Many international sporting organizations have recommended practices to reduce the risk of injury. These practices include screening for injury, having appropriate emergency medical care, and protocols for managing injury before return-to-play. The extent of the uptake of these practices in a developing country such as Uganda, is unknown. METHODOLOGY: Using a descriptive case study approach, this investigation focused on a sample of injured athletes (n = 75) in Uganda from four main sports associations (football, athletics, basketball and rugby). The data were collected through observations and interviews after the injury. Using a best medical practice framework the phases of emergency, intermediate, rehabilitative, and return-to-sports participation were described. RESULT: Nine conditions/types of injury were included. The results revealed a lack of specific pre-season screening or return-to-play readiness for all the injured athletes. Further, there was a lack of application of best practice principles for most of the injury types. For athletes who received medical care, the results show inconsistencies and inadequacies from the acute stage of the injury to return-to-sports participation. CONCLUSION: This study identified barriers such as up-to-date knowledge among the sports resource providers; the gaps for appropriate and adequate specific facilities for managing injured athletes, and policies to mandate care of injured athletes. These barriers detract from applying best medical practices.

Incidence of Injuries, Illness and Related Risk Factors in Cross-Country Marathon Mountain Biking Events: A Systematic Search and Review.

BACKGROUND: Cycling is a popular global sport and method of transportation and a significant contributor to admissions to hospital emergency units following an injury. Mountain biking events present additional challenges with remote venues and isolated courses, for which on-site medical care is often provided, for both injury and illness occurring during races. National health data may not represent these unique events, and specific data on incidence of injury and illness in mountain biking events are essential. Therefore, the aim of this study was to review the available injury and illness literature, reporting methods and risk factors in cross-country mountain biking. METHODS: Search engines PubMed, Scopus, CINAHL (EBSCOhost), Scopus, PEDro and the Cochrane Library were systematically searched, and a grey literature search was performed. Narrative analyses of the types, severity and area of injuries and illness type and severity were performed as pooling of data was impossible due to insufficient high-quality studies with the same injury and illness definitions. RESULTS: Seven studies comprising 28,021 participants were included for analysis. Four to 71% of participants sustained an injury in a cross-country mountain bike event. Injuries to the skin were the most common, followed by bony injuries and concussion. Five to 47% of cyclists reported the onset of gastrointestinal symptoms post-event. The prevalence of illness during events ranged from 0.5 to 23.0%. CONCLUSION: The injury and illness definitions were varied and prevented clear comparisons between studies. Injury and illness present a concern in cross-country marathon mountain biking and should be investigated further to provide the true burden of these during race events. Registration: This protocol has been registered with PROSPERO International prospective register of systematic reviews (No: CRD42019134586).

Tackle technique knowledge alone does not translate to proper tackle technique execution in training.

OBJECTIVES: Effective tackle technique is associated with reduced injury risks and improved performance in contact. Injury prevention programmes aim to provide players with knowledge of effective technique. However, little is known of the impact of this knowledge on a player's technique in the tackle. This study aimed to determine the association between knowledge of proper tackle technique and tackle technique proficiency in training. METHODS: Fifty-three rugby union players participated in a tackle contact drill and, thereafter, completed a questionnaire. The drill was filmed, and the players' tackle and ball-carry technique were assessed using standardised technical proficiency. In the questionnaire, the players were asked to rate the importance of each tackle and ball-carry technique on a 5-point Likert scale, for both injury prevention and performance tackle outcomes. Linear regression was performed to assess the relationship between the knowledge of the importance of proper tackle technique and tackle technique proficiency during the drill. RESULTS: No association was found between players' knowledge of the importance of proper technique and tackle contact technique in training for both injury prevention and performance. CONCLUSION: The lack of association between players' knowledge and actual tackle contact technique reveals the gap between the knowledge of safe and effective techniques and the knowledge of how to execute the said techniques.

Lay of the land: narrative synthesis of tackle research in rugby union and rugby sevens.

OBJECTIVES: The purpose of this review was to synthesise both injury prevention and performance tackle-related research to provide rugby stakeholders with information on tackle injury epidemiology, including tackle injury risk factors and performance determinants, and to discuss potential preventative measures. DESIGN: Systematic review and narrative synthesis. DATA SOURCES: PubMed, Scopus and Web of Science. ELIGIBILITY CRITERIA: Limited to peer-reviewed English-only publications between January 1995 and October 2018. RESULTS: A total of 317 studies were identified, with 177 in rugby union and 13 were in rugby sevens. The tackle accounted for more than 50% of all injuries in rugby union and rugby sevens, both at the professional level and at the lower levels, with the rate of tackle injuries higher at the professional level (mean 32/1000 player-hours) compared with the lower levels (mean 17/1000 player-hours). A player's tackle actions and technical ability were identified as major risk factors for injury and a key determinant of performance. SUMMARY/CONCLUSION: Evidence-based education, progressive tackle technique training with a high potential to transfer and law changes have been proposed as key modifiers of player tackle actions and technical ability. Conceivably, all three modifiers working in unison (as opposed to separately) will have a higher potential at reducing tackle injury risk while enhancing performance. With the guidance of tackle injury and performance studies, as well as stakeholder engagement, experiential and explorative tackle research has the potential to inspire innovative injury prevention and performance strategies.

Ankle osteoarthritis and its association with severe ankle injuries, ankle surgeries and health-related quality of life in recently retired professional male football and rugby players: a cross-sectional observational study.

OBJECTIVES: To determine (1) the prevalence of ankle osteoarthritis (OA) among former professional football and rugby players, (2) assess the association between ankle injuries or ankle surgeries with ankle OA, and (3) compare the mental and physical quality of life (QoL) between former professional football and rugby players with and without OA. METHODS: We conducted a questionnaire-based observational study with a cross-sectional design. Former professional football and rugby players were recruited by the Football Players Worldwide and the International Rugby Players. Information concerning ankle OA, sustained ankle injuries and ankle surgeries was gathered (medical record or most recent medical professional). Health-related QoL was assessed using the Patient-Reported Outcomes Measurement Information System (PROMIS) physical and mental health scores. RESULTS: Overall, 553 former professional football (n=401) and rugby (n=152) players were enrolled in the study (response rate of 56%). Ankle OA prevalence among former professional football and rugby players was 9.2% and 4.6%, respectively. Football players were more likely to suffer from ankle OA following every ankle injury and/or surgery. Football and rugby players with ankle OA had similar PROMIS physical and mental health scores to the norm for the general population. CONCLUSION: Former professional football and rugby players had higher ankle OA prevalence than the general population (3.4%). Football players are more likely to suffer from ankle OA following every ankle injury and/or surgery. No clinically relevant difference was seen for physical or mental health-related QoL among football and rugby players. Preventive measures for ankle injuries are recommended.

The effect of physical fatigue on tackling technique in Rugby Union.

OBJECTIVES: To measure the change in tackling technique of rugby union players following an acute bout of physically fatiguing exercise. DESIGN: Randomised cross-over study design with a physical fatigue condition and no-physical fatigue condition (control). METHODS: Nineteen male amateur club rugby union players (n=19) and a total of 887 tackles were analysed. During each condition, each player performed four sets of six tackles (three dominant and three non-dominant shoulder) on a contact simulator. Between each set of tackles in the physical fatigue condition, players performed the prolonged high-intensity intermittent running ability test. Using video, player's tackling proficiency for each tackle was measured by awarding either one point or zero points depending on whether a particular technique was performed or not. The sum of these points represents player's tackling proficiency (score out of 9, measured in arbitrary units). RESULTS: In the non-dominant shoulder, a difference between fatigue and control was found at set two (Fatigue 7.3 [7.1-7.6] AU vs. Control 7.6 [7.4-7.9] AU, p=0.06, ES=0.3 small) and set three (Fatigue 7.3 [7.0-7.5] AU vs. Control 7.7 [7.5-7.9] AU, p=0.006, ES=0.5 small). During the control condition, tackling proficiency scores improved from baseline for non-dominant tackles (Baseline 7.4 [7.2-7.6] AU, vs Set two 7.6 [7.4-7.9] AU, p=0.08 ES=0.3 small; vs Set three 7.7 [7.5-7.9] AU, p=0.05, ES=0.4 small). CONCLUSIONS: In conclusion, this study shows that physical fatigue can potentially affect rugby union players' tackling technique. Therefore, players should develop technical capacity to resist the effects of physical fatigue during the tackle.

Knowledge-guided analysis of "omics" data using the KnowEnG cloud platform.

We present Knowledge Engine for Genomics (KnowEnG), a free-to-use computational system for analysis of genomics data sets, designed to accelerate biomedical discovery. It includes tools for popular bioinformatics tasks such as gene prioritization, sample clustering, gene set analysis, and expression signature analysis. The system specializes in "knowledge-guided" data mining and machine learning algorithms, in which user-provided data are analyzed in light of prior information about genes, aggregated from numerous knowledge bases and encoded in a massive "Knowledge Network." KnowEnG adheres to "FAIR" principles (findable, accessible, interoperable, and reuseable): its tools are easily portable to diverse computing environments, run on the cloud for scalable and cost-effective execution, and are interoperable with other computing platforms. The analysis tools are made available through multiple access modes, including a web portal with specialized visualization modules. We demonstrate the KnowEnG system's potential value in democratization of advanced tools for the modern genomics era through several case studies that use its tools to recreate and expand upon the published analysis of cancer data sets.

Pacing characteristics of whole and part-game players in professional rugby union.

Contemporary theories on players' intensity distribution in team sports suggest that they regulate their outputs using pacing strategies. There is currently limited information on how movement patterns and pacing strategies of rugby union players in different position groups (forwards and backs) vary when exposed to different bout types (whole game, starter or finisher). Global positioning system (GPS) and accelerometer data were collected from 100 professional match participations to determine temporal effects on movement patterns. For forwards, finishers (players who entered the game as substitutes) demonstrated significantly greater high-speed running distance (% difference, ± 90%CI; magnitude-based inference and effect size) (↑ 55, ±17%; very likely large) and acceleration frequency (↑ 78, ±59%; very likely large) than whole game players. For backs, starters (players who started the game and were later substituted) displayed greater high-speed running distance than whole game players (↑ 27, ±21%; ES = likely medium) but this difference did not achieve statistical significance (p = .07). Forwards displayed "slow-positive" pacing strategies regardless of bout type, while backs displayed "flat" pacing strategies. Forwards and backs adopt different pacing strategies regardless of bout type, with forwards demonstrating progressively greater performance decrements over the course of the match. These findings reflect differing physical demands, notably contact and running loads, of players in different positions.

Technical determinants of tackle and ruck performance in International Rugby Sevens.

Abstract Rugby Sevens ('Sevens') is one of the fastest growing sports in the world. This growth was marked by the inclusion of the sport in the Olympic Games in 2016. The most frequently occurring contact events in Sevens are the tackle and ruck. Performing specific techniques during these contact events can reduce the risk of injury and increase the likelihood of success. Therefore, the purpose of this study was to identify the technical determinants associated with tackle and ruck performance outcomes in Sevens. A total of 4799 tackles and 1405 rucks from the 2014/2015 HSBC Sevens World Series were coded for contact, post-contact, ruck, match contextual variables and outcomes. Relative risk ratio (RR), the ratio of the probability of an outcome occurring when a variable was observed, was determined using multinomial logistic regression. A moderate ball-carrier leg drive reduced the probability of losing possession by 25% (RR 0.75, 95% CI, 0.58-0.97, p < .05). Conversely, ball-carriers had a 53% higher likelihood of losing possession when the tackler executed a moderate leg drive (RR 1.53, 95% CI, 1.09-2.14, p ≤ .05). Maintaining possession at the ruck was more likely to occur when committing one attacker compared to two (RR 0.31, 95% CI, 0.19-0.49, p < .001). Active ball-carrier placement also increased the likelihood of maintaining possession at the ruck (RR 14.67, 95% CI, 9.55-22.56, p < .001). Sevens coaches and trainers can now positively design evidence-based technical training programmes and emphasise specific tackle techniques in training using data from Sevens video analysis. Also, given that this is the first study to relate tackle technical determinants to an outcome (i.e. the first 'how' study) in Sevens, this work provides the foundation for similar Sevens video analysis studies in the future.