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To investigate the influence of previous season match exposure on injury incidence and burden in elite men's rugby union.A three-season (2016-17 to 2018-19) retrospective cohort design was used to collect and analyse injury and exposure data across English Premiership rugby union teams.Generalised linear mixed-effects models were used to model the influence of match exposure (all match involvements, match involvements of ≥20 mins, and full-game equivalents) upon match and training injury incidence and burden in the following season.Involvement in ≥31 matches within a season was associated with substantially increased match and training injury burden in the following season. Match exposure was not clearly associated with injury incidence in the following season. The increased match injury burden associated with higher match involvements appeared to be driven by an increased risk for older (26 y) Forwards, whilst the increased training injury burden associated with higher match involvements appeared to be driven by an increased risk for older (26 y) Backs.The present study demonstrates that all match involvements, regardless of duration, should be considered when exploring associations between match exposure and injury risk. High match involvements (≥ 31 matches) are associated with elevated injury burden, in both matches and training, in the following season. The physical and psychological load of players with high previous-season match exposure should be carefully managed.

ObjectiveTo establish match injury rates and patterns in elite female rugby union players in England.MethodWe conducted a six-season (2011/2012–2013/2014 and 2017/2018–2019/2020) prospective cohort study of time-loss match injuries in elite-level female players in the English Premiership competition. A 24-hour time-loss definition was used.ResultsFive-hundred and thirty-four time-loss injuries were recorded during 13 680 hours of match exposure. Injury incidence was 39 injuries per 1000 hours (95% CIs 36 to 42) with a mean severity of 48 days (95% CIs 42 to 54) and median severity of 20 days (IQR: 7–57). Concussion was the most common specific injury diagnosis (five concussions per 1000 hours, 95% CIs 4 to 6). The tackle event was associated with the greatest burden of injury (615 days absence per 1000 hours 95% CIs 340 to 1112), with ‘being tackled’ specifically causing the most injuries (28% of all injuries) and concussions (22% of all concussions).ConclusionsThis is the first multiple-season study of match injuries in elite women’s rugby union players. Match injury incidence was similar to that previously reported within international women’s rugby union. Injury prevention strategies centred on the tackle would focus on high-burden injuries, which are associated with substantial player time-loss and financial costs to teams as well as the high-priority area of concussions.

The use of artificial playing surfaces in professional rugby union is growing, but their effect on the injury risk profile remains unclear. The aim of this study was to examine the effect of playing surface on match injury risk in men's professional rugby in England. Six seasons of injury data (2013/14–2018/19) were collected from 15 professional English, men's rugby teams participating in domestic and European competition. The incidence, severity, and burden of match injuries were compared across playing surfaces. The dataset included 3351 injuries from a combined European and domestic data set (separated in to 2 categories; artificial and natural/hybrid surfaces) and 2675 injuries from a domestic only dataset (separated into 3 categories; artificial, hybrid, and natural surfaces). There were no differences in incidence rates between surface types on combined European and domestic match data, but injury burden was significantly greater on artificial (3082 days/1000 h, 95% CI 2847-3337) in comparison with natural/hybrid surfaces (2364 days/1000 h, 95% CI 2277–2454, p < 0.001). These differences were primarily driven by a significantly greater mean severity of hip/groin, and foot/toe injuries on artificial surfaces. This is the largest study to date to examine the relationship between surface type and injury risk in rugby union. The average severity and burden of injuries sustained on artificial surfaces was significantly greater compared with those sustained on hybrid/natural grass surfaces. This study can inform those involved in selection of surface for elite sport, weighing up the positive and negative elements of the varying surface types.

The COVID19-induced suspension of the 2019-20 professional England rugby union season resulted in players being exposed to an extended restricted training period, coupled with a congested match schedule once competition resumed. We assessed the impact of these changes on match and training injuries in the final 20-weeks of the season following competition resumption.Epidemiological study.The 2019-20 season was compared to the previous three seasons (2016-19).There was no significant difference in the mean incidence, severity and burden of training and match injuries in 2019-20 compared to 2016-19 period mean. The 2019-20 post-suspension mean match injury rate [77/1000 h (95%CIs [confidence intervals]: 67-89)] was comparable to the 2019-20 pre-suspension [93/1000 h (95%CIs: 85-101)] and significantly lower than the 2016-19 equivalent post-suspension period [97/1000 h (95CIs: 90-104) IRR [incidence rate ratio] 0.8 p=0.002]. In the 2019-20 season, there was a significantly higher rate of training injury post-suspension in comparison to pre-suspension [3.8/1000 h (95CIs: 3.3-4.4) vs 2.7/1000 h (95% CIs: 2.5-3.1) IRR 1.4 p=0.005]. There was no significant difference in the overall incidence, severity or burden of injuries sustained in fixtures with shorter (6 days) turnarounds but there was a significantly higher burden of soft tissue injuries.This is the first study to assess the effect of restricted training on injury risk in collision sports. Players were at an increased risk of training injury when returning from the suspension, but 10-weeks of preparatory training meant the incidence of match injury was not higher when competition resumed.

A multi-institutional team of undergraduate students conducted an independent study in which they designed, fabricated, and tested a small Hall effect thruster. The study was motivated by student desire to engage in a hands-on, multidisciplinary project in the field of space propulsion. This paper represents the outcome of this educational experiment. It describes the educational framework followed; the fundamental physics behind Hall thruster operation (at an early undergraduate level); the design process followed to develop and construct the thruster including a novel additively-manufactured propellant diffuser; and testing results. The thruster did not successfully ignite during testing. The cathode/plasma source was identified as the likely point of failure; rather than design flaws in the thruster itself, thereby introducing next steps for a future study following a similar framework. The educational program presented serves as a case study for a small-team undergraduate space propulsion project with limited resources and prior knowledge as well as a technical reference and knowledge base for future teams attempting a project of similar scope.

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.

Sports related head injuries can cause transient neurological events including loss of consciousness and dystonic posturing. However, it is unknown why head impacts that appear similar produce distinct neurological effects. The biomechanical effect of impacts can be estimated using computational models of strain within the brain. Here, we investigate the strain and strain rates produced by professional American football impacts that led to loss of consciousness, posturing or no neurological signs. We reviewed 1280 National Football League American football games and selected cases where the team’s medical personnel made a diagnosis of concussion. Videos were then analysed for signs of neurological events. We identified 20 head impacts that showed clear video signs of loss of consciousness and 21 showing clear abnormal posturing. Forty-one control impacts were selected where there was no observable evidence of neurological signs, resulting in 82 videos of impacts for analysis. Video analysis was used to guide physical reconstructions of these impacts, allowing us to estimate the impact kinematics. These were then used as input to a detailed 3D high-fidelity finite element model of brain injury biomechanics to estimate strain and strain rate within the brain. We tested the hypotheses that impacts producing loss of consciousness would be associated with the highest biomechanical forces, that loss of consciousness would be associated with high forces in brainstem nuclei involved in arousal and that dystonic posturing would be associated with high forces in motor regions. Impacts leading to loss of consciousness compared to controls produced higher head acceleration (linear acceleration; 81.5 g ± 39.8 versus 47.9 ± 21.4; P = 0.004, rotational acceleration; 5.9 krad/s2 ± 2.4 versus 3.5 ± 1.6; P < 0.001) and in voxel-wise analysis produced larger brain deformation in many brain regions, including parts of the brainstem and cerebellum. Dystonic posturing was also associated with higher deformation compared to controls, with brain deformation observed in cortical regions that included the motor cortex. Loss of consciousness was specifically associated with higher strain rates in brainstem regions implicated in maintenance of consciousness, including following correction for the overall severity of impact. These included brainstem nuclei including the locus coeruleus, dorsal raphé and parabrachial complex. The results show that in head impacts producing loss of consciousness, brain deformation is disproportionately seen in brainstem regions containing nuclei involved in arousal, suggesting that head impacts produce loss of consciousness through a biomechanical effect on key brainstem nuclei involved in the maintenance of consciousness.

AIM To describe trends in the incidence of match concussions and time to return-to-play in professional rugby union. METHODS Match concussion incidence (injuries per 1000 player-match-hours) and time to return-to-play (mean and median days absence) were recorded in 3006 male professional rugby union players over 16 seasons (2002/03 - 2018/19). RESULTS From 2002/03 to 2009/10, incidence of concussions was stable at 4.3/1000 player-match-hours. From 2009/10 to 2018/19, there was an increase in concussion incidence, with the highest incidence in 2016/17 at 20.9/1000 player-match-hours (95% CI: 17.9-24.3). Annual prevalence of concussion also increased, suggesting more players were concussed rather than the same players sustaining more concussions. Before the introduction of standardized graduated return-to-play (GRTP) guidelines in 2011, 27% of players returned to play in

This study evaluated the validity and utility of antigen-detection rapid diagnostic tests (Ag-RDTs) for SARS-CoV-2 in elite sports. The data on utility, ease of use and application for Ag-RDTs as a new testing format were positive from players and staff. This evaluation was limited by the low prevalence of SARS-CoV-2 circulating within the three squads. This study highlights the need for continued service evaluations for SARS-CoV-2 Ag-RDTs in elite sport settings.

Personal Carbon Budgets (PCBs) are a radical policy innovation that seek to reduce an individual’s carbon consumption. This review identifies three archetypes of PCBs in the current literature; Personal Carbon Trading, Carbon Tax and Carbon Labelling. We theorised that carbon trading could affect equity and allow quality of life and consumption to be driven by income rather than needs. We, therefore, developed a new model (Personal Carbon Allowance with no trading) to compare to existing archetypes. A PESTLE (Political, Economic, Social, Technological, Legal, Environmental) framework was applied to each archetype to analyse and compare their costs and benefits and to critically evaluate and identify which model may be the most appropriate to reduce emissions severely but equitably. We conclude that the only model that can achieve this is our proposed Personal Carbon Allowance (PCA) model with no trading. PCA has a hard cap on emissions allowing for controllable severe cuts to emissions, and the lack of trading would prohibit those with wealth from continuing high-consumption lifestyles at the expense of those with lower incomes.

ObjectiveThe BRAIN Study was established to assess the associations between self-reported concussions and cognitive function among retired rugby players.MethodsFormer elite-level male rugby union players (50+ years) in England were recruited. Exposure to rugby-related concussion was collected using the BRAIN-Q tool. The primary outcome measure was the Preclinical Alzheimer Cognitive Composite (PACC). Linear regressions were conducted for the association between concussion and PACC score, adjusting for confounders.ResultsA total of 146 participants were recruited. The mean (standard deviation) length of playing career was 15.8 (5.4) years. A total of 79.5% reported rugby-related concussion(s). No association was found between concussion and PACC (β –0.03 [95% confidence interval (CI): –1.31, 0.26]). However, participants aged 80+ years reporting 3+ concussions had worse cognitive function than those without concussion (β –1.04 [95% CI: –1.62, –0.47]).ConclusionsOverall there was no association between concussion and cognitive function; however, a significant interaction with age revealed an association in older participants.

Funder: Medical Research Council; FundRef: http://dx.doi.org/10.13039/501100000265, Funder: National Institute for Health Research; FundRef: http://dx.doi.org/10.13039/501100000272, Funder: Marker Diagnostics, Funder: Rugby Football Union, Funder: Midland Neuroscience Teaching and Research Fund, Objective: To investigate the role of salivary small non-coding RNAs (sncRNAs) in the diagnosis of sport-related concussion. Methods: Saliva was obtained from male professional players in the top two tiers of England’s elite rugby union competition across two seasons (2017–2019). Samples were collected preseason from 1028 players, and during standardised head injury assessments (HIAs) at three time points (in-game, post-game, and 36–48 hours post-game) from 156 of these. Samples were also collected from controls (102 uninjured players and 66 players sustaining a musculoskeletal injury). Diagnostic sncRNAs were identified with next generation sequencing and validated using quantitative PCR in 702 samples. A predictive logistic regression model was built on 2017–2018 data (training dataset) and prospectively validated the following season (test dataset). Results: The HIA process confirmed concussion in 106 players (HIA+) and excluded this in 50 (HIA−). 32 sncRNAs were significantly differentially expressed across these two groups, with let-7f-5p showing the highest area under the curve (AUC) at 36–48 hours. Additionally, a combined panel of 14 sncRNAs (let-7a-5p, miR-143-3p, miR-103a-3p, miR-34b-3p, RNU6-7, RNU6-45, Snora57, snoU13.120, tRNA18Arg-CCT, U6-168, U6-428, U6-1249, Uco22cjg1,YRNA_255) could differentiate concussed subjects from all other groups, including players who were HIA− and controls, immediately after the game (AUC 0.91, 95% CI 0.81 to 1) and 36–48 hours later (AUC 0.94, 95% CI 0.86 to 1). When prospectively tested, the panel confirmed high predictive accuracy (AUC 0.96, 95% CI 0.92 to 1 post-game and AUC 0.93, 95% CI 0.86 to 1 at 36–48 hours). Conclusions: SCRUM, a large prospective observational study of non-invasive concussion biomarkers, has identified unique signatures of concussion in saliva of male athletes diagnosed with concussion.

ObjectivesTo examine the interactions between SARS-CoV-2 positive players and other players during rugby league matches and determine within-match SARS-CoV-2 transmission risk.MethodsFour Super League matches in which SARS-CoV-2 positive players were subsequently found to have participated were analysed. Players were identified as increased-risk contacts, and player interactions and proximities were analysed by video footage and global positioning system (GPS) data. The primary outcome was new positive cases of SARS-CoV-2 within 14 days of the match in increased-risk contacts and other players participating in the matches.ResultsOut of 136 total players, there were 8 SARS-CoV-2 positive players, 28 players identified as increased-risk contacts and 100 other players in the matches. Increased-risk contacts and other players were involved in 11.4±9.0 (maximum 32) and 4.0±5.2 (maximum 23) tackles, respectively. From GPS data, increased-risk contacts and other players were within 2 m of SARS-CoV-2 positive players on 10.4±18.0 (maximum 88) and 12.5±20.7 (maximum 121) occasions, totalling 65.7±137.7 (maximum 689) and 89.5±169.4 (maximum 1003) s, respectively. Within 14 days of the match, one increased-risk contact and five players returned positive SARS-CoV-2 reverse transcriptase PCR (RT-PCR) tests, and 27 increased-risk contacts and 95 other participants returned negative SARS-CoV-2 RT-PCR tests. Positive cases were most likely traced to social interactions, car sharing and wider community transmission and not linked to in-match transmission.ConclusionDespite tackle involvements and close proximity interactions with SARS-CoV-2 positive players, in-match SARS-CoV-2 transmission was not confirmed. While larger datasets are needed, these findings suggest rugby presents a lower risk of viral transmission than previously predicted.

People’s placement of numbers on number lines sometimes shows linear and sometimes compressive scaling. We investigated whether people’s placement of numbers was affected by their range and distribution, as indicated by Parducci’s (Psychological Review, 72, 407–418, 1965) range-frequency theory. Experiment 1 found large compressive effects when the endpoints were 1 and 1016. Experiment 2 showed compression when 14 logarithmically distributed numbers were placed on a line marked 1–1,000 and close to linear scaling when the numbers were linearly distributed. Thus, we found both range and frequency effects on compression. Where compression arose, it was not as pronounced as that predicted by logarithmic scaling, but analyses of the results from Experiments 1 and 2 indicate this was not explained by participants switching between linear and logarithmic scaling.

Laryngeal trauma is a life‐threatening injury in contact sports. Due to its potentially devastating consequences, the prevention, diagnosis, and management of neck trauma both pitch side and at the hospital are essential for athletes.

In this work we use a mix of statistical analysis and process-based modeling with the decision support system for agrotechnology transfer (DSSAT) crop modelling platform to investigate the two issues of great concern for sustaining agricultural productivity in warming Canada. These are the changing crop response to environmental stresses as crop technology develops and the crop responses to changing weather in the current growth environment and at higher latitudes. The research has shown increased sensitivity of new oats, barley and spring wheat cultivars in Saskatchewan to mostly unchanged daytime temperatures, between 1961 and 2000. Increasing nighttime temperatures impacted oats, barley and spring wheat yields negatively between 1981 and 2000. In another aspect of the research, we selected cultivar and soil combinations to project yields into the climate changed future with DSSAT, without changing technology. Selection was based on the smallest root mean squared error (RMSE) in simulated yields compared with measurement, 1987 to 2016, provided that their correlations were significant at the 5% level. Planted areas prioritised the influence of county yields in the aggregations to representative subregional values for northern and southern Southwestern Ontario. The representative maize ecotypes and/or cultivars identified for various Southwestern Ontario counties were Pio-3563, GL482, 2600-2650-GDD, Dekalb-485, Pio-3192, Pio-3147 and Mokwa-87TZPB-SR, while for soybean these were M-Group-000, M-Group-00, Altona (00), and M-Group-0. Data from 4 regional climate models (RCM) were used in DSSAT runs to project soybean and maize yields into the climate changed future, to year 2069, under the RCP8.5 scenario. We found that soybean can withstand most of the high temperatures expected under RCP8.5, while maize cannot and hence maize is likely to have decreasing yields in Southwestern Ontario from the late 2030s. Nevertheless, in this enhanced warming scenario, soybean and maize planted in Cochrane District, Northern Ontario, in the mid 2020s and 2030s respectively, can yield at least 80% of their maximums attainable by the mid-to-late 2040s. Decreasing precipitation would be of greatest concern in relation to changes in soybean yield, while increasing temperatures would be of greatest concern in relation to changes in maize yield. Ontario Ministry of Agriculture, Food and Rural Affairs

Interpreting the physical qualities of youth athletes is complex due to the effects of growth, maturation and development. This study aimed to evaluate the effect of position, chronological age, relative age and maturation on the physical qualities of elite male academy rugby union players. 1,424 participants (n=2,381 observations) from nine Rugby Football Union Regional Academies prospectively completed a physical testing battery at three time points, across three playing seasons. Anthropometrics, body composition, muscular power, muscular strength, speed, aerobic capacity and running momentum were assessed. Positional differences were identified for all physical qualities. The largest effect sizes were observed for the associations between chronological age (d=0.65 to 0.73) and maturation (d=-0.77 to -0.69) and body mass related variables (i.e. body mass and running momentum). Relative strength, maximum velocity and aerobic capacity were the only models to include two fixed effects with all other models including at least three fixed effects (i.e. position and a combination of chronological age, relative age and maturation). These findings suggest a multidimensional approach considering position, chronological age, relative age and maturation is required to effectively assess the physical qualities of male age grade rugby union players. Therefore practitioners should use regression equations rather than traditional descriptive statistic tables to provide individualised normative comparisons thus enhancing the application of testing results for talent identification and player development.

Nostalgia as a concept historically underwent semantic transformations from a maladaptive disease to a possibly positive universal phenomenon. Concepts are often accompanied by cultural and historical connotations. This paper describes two studies that examined cultural differences in nostalgic experience (Study 1) and differences in understanding nostalgia and attitudes towards one’s personal past and the historical past of one’s culture (Study 2). The nostalgic experience was found to differ between New Zealanders and Indians, where the latter had more negative, intense and longer experiences. These differences were not a result of differences in life satisfaction or appraisal of the past; however, they might have been due to differences in conceptualisation of nostalgia and type of nostalgic events recalled. The findings suggest that cultural understanding and conceptualisation of nostalgia, independent of wellbeing metrics that apply to the individual, contribute to differences in nostalgic experiences.

Background: The use of artificial turf on rugby pitches is increasingly commonplace but there is limited evidence around its effects on injury, recovery, and performance. It is unclear whether this uncertainty influences player management strategies in professional clubs. Objectives: To understand how professional rugby union clubs in England approach player management for artificial turf, to explore how the beliefs of medical and strength/conditioning staff influence these decisions, and to determine whether differences exist between clubs with different levels of exposure to artificial surfaces. Methods: The study was a cross-sectional mixed methods study. Twenty-three medical and strength/conditioning staff members from 12 English Premiership Rugby Union clubs completed two bespoke questionnaires and participated in a semi-structured interview. Results: Two-thirds of the participants described formal club-level approaches to artificial turf. All participants from low- exposure clubs (

Purpose While kicking in Rugby Union can be influential to match outcome, the epidemiology of kicking injuries remains unknown. This study therefore aimed to investigate the epidemiology of injuries attributed to kicking in professional rugby, including playing position-specific effects and differences in kicking volumes and kick types. Methods Fifteen seasons of injury surveillance data and two seasons of match kicking characteristics from professional rugby players were analyzed. Incidence, propensity, and severity of kicking-related injuries were calculated together with the locations and types of these injuries. Position-related differences in match kicking types and volumes were also established. Results Seventy-seven match and 55 training acute-onset kicking injuries were identified. The match kicking injury incidence for backs was 1.4/1000 player-match-hours. Across all playing positions, the propensity for match kicking injury was 0.57 injuries/1000 kicks. Fly-halves sustained the greatest proportion of match kicking injuries (47%) and performed the greatest proportion of match kicks (46%); an average propensity for match kicking injury (0.58/1000 kicks). Scrum-halves executed 27% of match-related kicks but had a very low propensity for match kicking injury (0.17/1000 kicks). All other positional groups executed a small proportion of match-related kicks but a high propensity for match kicking injury. Ninety-two percent of match kicking injuries occurred in the pelvis or lower limb, with the majority sustained by the kicking limb. 21% of all match kicking injuries were associated with the rectus femoris muscle. Conclusion Match kicking profiles and kicking injuries sustained are position-dependent, which provides valuable insight for developing player-specific conditioning and rehabilitation protocols.

The COVID-19 pandemic in 2020 has resulted in widespread training disruption in many sports. Some athletes have access to facilities and equipment, while others have limited or no access, severely limiting their training practices. A primary concern is that the maintenance of key physical qualities (e. g. strength, power, high-speed running ability, acceleration, deceleration and change of direction), game-specific contact skills (e. g. tackling) and decision-making ability, are challenged, impacting performance and injury risk on resumption of training and competition. In extended periods of reduced training, without targeted intervention, changes in body composition and function can be profound. However, there are strategies that can dramatically mitigate potential losses, including resistance training to failure with lighter loads, plyometric training, exposure to high-speed running to ensure appropriate hamstring conditioning, and nutritional intervention. Athletes may require psychological support given the challenges associated with isolation and a change in regular training routine. While training restrictions may result in a decrease in some physical and psychological qualities, athletes can return in a positive state following an enforced period of rest and recovery. On return to training, the focus should be on progression of all aspects of training, taking into account the status of individual athletes.

Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport-specific or setting-specific consensus statements on sports injury (and, eventually, illness) epidemiology to date. Our objective was to further strengthen consistency in data collection, injury definitions and research reporting through an updated set of recommendations for sports injury and illness studies, including a new Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist extension. The IOC invited a working group of international experts to review relevant literature and provide recommendations. The procedure included an open online survey, several stages of text drafting and consultation by working groups and a 3-day consensus meeting in October 2019. This statement includes recommendations for data collection and research reporting covering key components: defining and classifying health problems; severity of health problems; capturing and reporting athlete exposure; expressing risk; burden of health problems; study population characteristics and data collection methods. Based on these, we also developed a new reporting guideline as a STROBE Extension-the STROBE Sports Injury and Illness Surveillance (STROBE-SIIS). The IOC encourages ongoing in- and out-of-competition surveillance programmes and studies to describe injury and illness trends and patterns, understand their causes and develop measures to protect the health of the athlete. Implementation of the methods outlined in this statement will advance consistency in data collection and research reporting. Funding Agencies|International Olympic Committee

We experimentally investigate whether framing an individual-choice decision in a market setting results in a different outcome than when the decision is described in a context-free frame. We further explore whether the context effect is triggered solely by the frame or whether a richer descriptive content is required to establish familiarity with the decision-making environment. Understanding what constitutes context is central to formulating practical recommendations aiming to improve the quality of individual decisions. Our results show that framing a sequential search problem as selling houses leads to better decisions than a context-free frame. Manipulating whether or not the framed decision-making scenario includes a description of the house, which would be naturally available in a real estate market, does not impact the length of search or the value of accepted offers.

Nostalgia is a complex affective state with a strong cognitive component focussed on past autobiographical memories. This complex nature of nostalgia is discussed in the literature but there are scarce empirical observations of state nostalgic processes. In this study, the operational process of nostalgia is explored by the use of two types of stimuli—indirect (instructions) and direct (music)—with a sample of 285 participants (18–35 years old) in a mixed-method experimental design. Nostalgia was observed in terms of its operational process (reaction time, duration, intensity and variation), the characteristics of the recalled event (event type and contents), and the nature of the nostalgic experience (its phenomenology, affect and motivation). The studied parameters of all three nostalgic components were found to vary with the stimulus that triggered it. The study shows that nostalgia is not a constant phenomenon but depends on the conditions that give rise to it.

Background: One strategy to prevent and manage concussion is to reduce head impacts, both those resulting in concussion and those that do not. Because objective data on the frequency and intensity of head impacts in rugby union (rugby) are sparse, stakeholders resort to individual perceptions to guide contact training. It is unknown whether there is a level of contact training that is protective in preparing elite players for contact during matches. Objectives: This study aimed to describe how contact training is managed in elite male rugby, and how staff and players perceive contact training load and head impact load. Methods: This was a sequential explanatory mixed-methods study. Forty-four directors of rugby, defence coaches, medical and strength/conditioning staff and 23 players across all 13 English Premiership Rugby Union clubs and the National senior team participated in semi-structured focus groups and completed two bespoke questionnaires. Results: The study identified the varied understanding of what constitutes head impact exposure across all stakeholder groups, resulting in different interpretations and a range of management strategies. The findings suggest that elite clubsconduct low levels of contact training; however, participants believe that some exposure is required to prepare players andthat efforts to reduce head impact exposure must allow for individualised contact training prescription. Conclusion: There is a need for objective data, possibly from instrumented mouthguards to identify activities with a high risk for head impact and possible unintended consequences of reduced exposure to these activities. As data on head impact exposure develop, this must be accompanied with knowledge exchange within the rugby community.

ObjectivesMost concussions in rugby union occur during tackles. We investigated whether legislation to lower maximum tackle height would change tackle behaviour, and reduce concussion incidence rate.MethodsIn an observational evaluation using a prospective cohort design, 12 elite men’s teams played in two competitions during the 2018/2019 season. The Championship (90 games) retained standard Laws of Rugby for the tackle; the Championship Cup (36 games) used revised laws—the maximum tackle height was lowered from the line of the shoulders on the ball carrier to the line of the armpits. Videos of tackles were analysed for ball carrier and tackler behaviour. Injury data were collected using standardised methods.ResultsIn the lowered tackle height setting, there was a significantly lower proportion of tackles; (1) in which ball carriers (rate ratio (RR) 0.83, 95% CI 0.79 to 0.86) and tacklers (RR 0.80, 95% CI 0.76 to 0.84) were upright, (2) in which the tackler’s initial contact was to the ball carrier’s head or neck (RR 0.70, 95% CI 0.58 to 0.84) and (3) in which initial contact was above the line of the ball carrier’s armpit (RR 0.84, 95% CI 0.80 to 0.88). Concussion incidence rate did not differ between conditions (RR 1.31, 95% CI 0.85 to 2.01). Unexpectedly, compared with the standard tackle height setting, tacklers in the lowered tackle height setting were themselves concussed at a higher rate as measured by; (1) incidence (RR 1.90, 95% CI 1.05 to 3.45) and (2) concussions per 1000 tackles (2.09, 95% CI 1.15 to 3.80).ConclusionsLegislating to lower the height of the tackle meant that tacklers made contact with the ball carrier’s head and neck 30% less often. This did not influence concussion incidence rates. Tacklers in the lowered tackle height setting suffered more concussions than did tacklers in the standard tackle height setting.