The biomechanical signature of loss of consciousness: computational modelling of elite athlete head injuries.

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.

Longitudinal study of six seasons of match injuries in elite female rugby union.

ObjectiveTo establish match injury rates and patterns in elite female rugby union players in England. METHOD: We 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. RESULTS: Five-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). CONCLUSIONS: This 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.

When should an athlete retire or discontinue participating in contact or collision sports following sport-related concussion? A systematic review.

OBJECTIVE: To systematically review the scientific literature regarding factors to consider when providing advice or guidance to athletes about retirement from contact or collision sport following sport-related concussion (SRC), and to define contraindications to children/adolescent athletes entering or continuing with contact or collision sports after SRC. DATA SOURCES: Medline, Embase, SPORTSDiscus, APA PsycINFO, CINAHL and Cochrane Central Register of Controlled Trials were searched systematically. STUDY ELIGIBILITY CRITERIA: Studies were included if they were (1) original research, (2) reported on SRC as the primary source of injury, (3) evaluated the history, clinical assessment and/or investigation of findings that may preclude participation in sport and (4) evaluated mood disturbance and/or neurocognitive deficits, evidence of structural brain injury or risk factors for increased risk of subsequent SRC or prolonged recovery. RESULTS: Of 4355 articles identified, 93 met the inclusion criteria. None of the included articles directly examined retirement and/or discontinuation from contact or collision sport. Included studies examined factors associated with increased risk of recurrent SRC or prolonged recovery following SRC. In general, these were low-quality cohort studies with heterogeneous results and moderate risk of bias. Higher number and/or severity of symptoms at presentation, sleep disturbance and symptom reproduction with Vestibular Ocular Motor Screen testing were associated with prolonged recovery and history of previous concussion was associated with a risk of further SRC. CONCLUSION: No evidence was identified to support the inclusion of any patient-specific, injury-specific or other factors (eg, imaging findings) as absolute indications for retirement or discontinued participation in contact or collision sport following SRC. PROSPERO REGISTRATION NUMBER: CRD42022155121.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review.

OBJECTIVES: To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6). DATA SOURCES: Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation. ELIGIBILITY CRITERIA: (1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC. DATA EXTRACTION: Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool. RESULTS: Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children. CONCLUSION: Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes. PROSPERO REGISTRATION NUMBER: CRD42020154787.

Influence of playing surface on match injury risk in men's professional rugby union in England (2013-2019).

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.

Concussion and long-term cognitive function among rugby players-The BRAIN Study.

OBJECTIVE: The BRAIN Study was established to assess the associations between self-reported concussions and cognitive function among retired rugby players. METHODS: Former 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. RESULTS: A 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 (ß -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 (ß -1.04 [95% CI: -1.62, -0.47]). CONCLUSIONS: Overall there was no association between concussion and cognitive function; however, a significant interaction with age revealed an association in older participants.

Trends in match concussion incidence and return-to-play time in male professional Rugby Union: A 16-season prospective cohort study.

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 <6 days. After the introduction of the GRTP, this decreased to 7%, with no players returning in <6 days after 2014/15. Between 2002/03 and 2018/19, incidence of all other injuries remained stable. CONCLUSIONS: From 2009/10 onwards, the incidence of diagnosed concussions increased. Since the introduction of the GRTP, there has been a dramatic reduction in the number of players returning in <6 days.

Does reducing the height of the tackle through law change in elite men's rugby union (The Championship, England) reduce the incidence of concussion? A controlled study in 126 games.

OBJECTIVES: Most 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. METHODS: In 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. RESULTS: In 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). CONCLUSIONS: Legislating 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.

SARS-CoV-2 transmission during rugby league matches: do players become infected after participating with SARS-CoV-2 positive players?

OBJECTIVES: To 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. METHODS: Four 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. RESULTS: Out 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. CONCLUSION: Despite 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.

Trends in match injury risk in professional male rugby union: a 16-season review of 10 851 match injuries in the English Premiership (2002-2019): the Professional Rugby Injury Surveillance Project.

OBJECTIVES: The Professional Rugby Injury Surveillance Project is the largest and longest running rugby union injury surveillance project globally and focuses on the highest level of rugby in England. METHODS: We examined match injuries in professional men's rugby over the period 2002/2003 to 2018/2019 and described trends in injuries over this time. RESULTS: Over the period 2002/2003-2018/2019, 10 851 injuries occurred in 1 24 952 hours of match play, equating to a mean of 57 injuries per club per season and one injury per team per match. The mean incidence, severity (days absence) and burden (days absence/1000 hours) of injury were 87/1000 hours (95% CI 82 to 92), 25 days (95% CI 22 to 28) and 2178 days/1000 hours (95% CI 1872 to 2484), respectively. The tackle accounted for 43% injuries with running the second most common activity during injury (12%). The most common injury location was the head/face with an incidence of 11.3/1000 hours, while the location with the highest overall burden was the knee (11.1 days/1000 hours). Long-term trends demonstrated stable injury incidence and proportion of injured players, but an increase in the mean and median severity of injuries. Concussion incidence, severity and burden increased from the 2009/2010 season onwards and from 2011 to 2019 concussion was the most common injury. CONCLUSION: The rise in overall injury severity and concussion incidence are the most significant findings from this work and demonstrate the need for continued efforts to reduce concussion risk as well as a greater understanding of changes in injury severity over time.

The relationships between rugby union, and health and well-being: a scoping review.

OBJECTIVE: To scope the relationships between rugby union, and health and well-being. DESIGN: Scoping review. DATA SOURCES: Published and unpublished reports of any age, identified by searching electronic databases, platforms and reference lists. METHODS: A three-step search strategy identified relevant published primary, secondary studies and grey literature, which were screened using a priori inclusion criteria. Data were extracted using a standardised tool, to form (1) a numerical analysis and (2) a thematic summary. RESULTS AND DISCUSSION: 6658 records were identified, and 198 studies met the inclusion criteria. All forms of rugby union can provide health-enhancing physical activity (PA). 'Non-contact' and wheelchair rugby in particular provide a wide range of physical and mental health and well-being benefits. The evidence is either mixed or unclear in relation to 'contact' rugby union and its effects on a range of physical health domains. Injury and concussion incidence rates are high for contact rugby union relative to other sports. CONCLUSIONS: A wide range of stakeholders as well as existing and potential participants can use this information to make a more informed decision about participating in and promoting rugby union as a health-enhancing activity. Industry and policy-makers can use this review to inform policies and strategies that look to increase participation rates and use rugby union as a vehicle to contribute positively to population health. Further research understanding rugby union's contribution to PA as well as to muscle-strengthening and balance is indicated, as well as research examining more health and well-being outcomes across more diverse cohorts.

Unique diagnostic signatures of concussion in the saliva of male athletes: the Study of Concussion in Rugby Union through MicroRNAs (SCRUM).

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.

Measuring Psychological Load in Sport.

Monitoring the physical load undertaken by athletes and examining the subsequent relationship with performance and injury and illness risk is common practice in high performance sport. Less attention has been paid to the psychological factors contributing to the overall load experienced and the impact upon health status and performance. This paper discusses considerations for the conceptualization and measurement of psychological load in sport. First, we outline the importance of ensuring conceptual clarity is adopted in the measurement of psychological load. Next, we discuss the challenges to measuring psychological load in a comparable manner to which physical load is currently evaluated, including use of subjective assessment, adoption of specific and global approaches, and development of measurement instrumentation, techniques, and expertise. We then offer recommendations for practitioners when undertaking assessment of psychological load in sport. We conclude with future research directions to advance the study and measurement of the construct, including the interaction between psychological and physical load, the appraisal of the load faced, and personal and social resources available to successfully cope. We also highlight the need to consider groups of athletes (e. g., transitioning athlete, long-term injured) at greater risk from threats to mental and physical health from increased psychological load.

The Potential for Airborne Transmission of SARS-CoV-2 in Sport: A Cricket Case Study.

A review of risk factors affecting airborne transmission of SARS-CoV-2 was synthesised into an 'easy-to-apply' visual framework. Using this framework, video footage from two cricket matches were visually analysed, one pre-COVID-19 pandemic and one 'COVID-19 aware' game in early 2020. The number of opportunities for one participant to be exposed to biological secretions belonging to another participant was recorded as an exposure, as was the estimated severity of exposure as defined from literature. Events were rated based upon distance between subjects, relative orientation of the subjects, droplet generating activity performed (e. g., talking) and event duration. In analysis we reviewed each risk category independently and the compound effect of an exposure i. e., the product of the scores across all categories. With the application of generic, non-cricket specific, social distancing recommendations and general COVID-19 awareness, the number of exposures per 100 balls was reduced by 70%. More impressive was the decrease in the most severe compound ratings (those with two or more categories scored with the highest severity) which was 98% and the reduction in exposures with a proximity <1 m, 96%. Analysis of the factors effecting transmission risk indicated that cricket was likely to present a low risk, although this conclusion was somewhat arbitrary omitting a comparison with a non-cricketing activity.

Training Load and Injury Risk in Elite Rugby Union: The Largest Investigation to Date.

Training load monitoring has grown in recent years with the acute:chronic workload ratio (ACWR) widely used to aggregate data to inform decision-making on injury risk. Several methods have been described to calculate the ACWR and numerous methodological issues have been raised. Therefore, this study examined the relationship between the ACWR and injury in a sample of 696 players from 13 professional rugby clubs over two seasons for 1718 injuries of all types and a further analysis of 383 soft tissue injuries specifically. Of the 192 comparisons undertaken for both injury groups, 40% (all injury) and 31% (soft tissue injury) were significant. Furthermore, there appeared to be no calculation method that consistently demonstrated a relationship with injury. Some calculation methods supported previous work for a "sweet spot" in injury risk, while a substantial number of methods displayed no such relationship. This study is the largest to date to have investigated the relationship between the ACWR and injury risk and demonstrates that there appears to be no consistent association between the two. This suggests that alternative methods of training load aggregation may provide more useful information, but these should be considered in the wider context of other established risk factors.

Padded Headgear does not Reduce the Incidence of Match Concussions in Professional Men's Rugby Union: A Case-control Study of 417 Cases.

Concussion is the most common match injury in rugby union. Some players wear padded headgear, but whether this protects against concussion is unclear. In professional male rugby union players, we examined: (i) the association between the use of headgear and match concussion injury incidence, and (ii) whether wearing headgear influenced time to return to play following concussion. Using a nested case-control within a cohort study, four seasons (2013-2017) of injury data from 1117 players at the highest level of rugby union in England were included. Cases were physician-diagnosed concussion injuries. Controls were other contact injuries (excluding all head injuries). We determined headgear use by viewing video footage. Sixteen percent of cases and controls wore headgear. Headgear use had no significant effect on concussion injury incidence (adjusted odds ratio=1.05, 95% CI: 0.71-1.56). Median number of days absent for concussion whilst wearing headgear was 8 days, compared with 7 days without headgear. Having sustained a concussion in the current or previous season increased the odds of concussion more than four-fold (odds ratio=4.55, 95% CI: 3.77-5.49). Wearing headgear was not associated with lower odds of concussions or a reduced number of days' absence following a concussion.

Increased yield and CO2 sequestration potential with the C4 cereal Sorghum bicolor cultivated in basaltic rock dust-amended agricultural soil.

Land-based enhanced rock weathering (ERW) is a biogeochemical carbon dioxide removal (CDR) strategy aiming to accelerate natural geological processes of carbon sequestration through application of crushed silicate rocks, such as basalt, to croplands and forested landscapes. However, the efficacy of the approach when undertaken with basalt, and its potential co-benefits for agriculture, require experimental and field evaluation. Here we report that amending a UK clay-loam agricultural soil with a high loading (10 kg/m2 ) of relatively coarse-grained crushed basalt significantly increased the yield (21 ± 9.4%, SE) of the important C4 cereal Sorghum bicolor under controlled environmental conditions, without accumulation of potentially toxic trace elements in the seeds. Yield increases resulted from the basalt treatment after 120 days without P- and K-fertilizer addition. Shoot silicon concentrations also increased significantly (26 ± 5.4%, SE), with potential benefits for crop resistance to biotic and abiotic stress. Elemental budgets indicate substantial release of base cations important for inorganic carbon removal and their accumulation mainly in the soil exchangeable pools. Geochemical reactive transport modelling, constrained by elemental budgets, indicated CO2 sequestration rates of 2-4 t CO2 /ha, 1-5 years after a single application of basaltic rock dust, including via newly formed soil carbonate minerals whose long-term fate requires assessment through field trials. This represents an approximately fourfold increase in carbon capture compared to control plant-soil systems without basalt. Our results build support for ERW deployment as a CDR technique compatible with spreading basalt powder on acidic loamy soils common across millions of hectares of western European and North American agriculture.

Concussion and long-term cognitive impairment among professional or elite sport-persons: a systematic review.

INTRODUCTION: Understanding whether concussion in sport is associated with worsening cognitive function in later life will likely have immediate repercussion on sports concussion prevention and management policy and sporting rules and regulations. This systematic review aims to summarise the evidence on the association between concussion sustained by professional/elite athletes and long-term cognitive impairment. METHODS: Embase, PubMed and Web of Science were used to search for eligible studies. Studies including professional/elite athletes from any sport were considered. Three comparison groups were considered: internal comparison (concussed vs non-concussed athletes within the same sample); between-sport comparison (contact sport athletes vs non-contact sports ones); external comparison (athletes vs samples of the general population or population norms). RESULTS: 14 studies were included (rugby, American football, ice hockey players, boxers and marital art fighters). The general quality of the evidence was poor. The overall evidence, weighted for type of comparison and study quality, points towards an association between sustaining a sport-related concussion and poorer cognitive function later in life in rugby, American football and boxing, although it is unclear to what extent this is clinically relevant. Data on ice hockey and martial arts were too sparse to allow conclusions to be drawn. CONCLUSION: High-quality, appropriately designed and powered epidemiological studies are urgently needed to assess the association between sustaining a sport-related concussion and cognitive impairment later in life. Particular emphasis should be put on the clinical translational value of findings.

The epidemiology of kicking injuries in professional Rugby Union: A 15-season prospective study.

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.

Consensus on a video analysis framework of descriptors and definitions by the Rugby Union Video Analysis Consensus group.

Using an expert consensus-based approach, a rugby union Video Analysis Consensus (RUVAC) group was formed to develop a framework for video analysis research in rugby union. The aim of the framework is to improve the consistency of video analysis work in rugby union and help enhance the overall quality of future research in the sport. To reach consensus, a systematic review and Delphi method study design was used. After a systematic search of the literature, 17 articles were used to develop the final framework that described and defined key actions and events in rugby union (rugby). Thereafter, a group of researchers and practitioners with experience and expertise in rugby video analysis formed the RUVAC group. Each member of the group examined the framework of descriptors and definitions and rated their level of agreement on a 5-point agreement Likert scale (1: strongly disagree; 2: disagree; 3: neither agree or disagree; 4: agree; 5: strongly agree). The mean rating of agreement on the five-point scale (1: strongly disagree; 5: strongly agree) was 4.6 (4.3-4.9), 4.6 (4.4-4.9), 4.7 (4.5-4.9), 4.8 (4.6-5.0) and 4.8 (4.6-5.0) for the tackle, ruck, scrum, line-out and maul, respectively. The RUVAC group recommends using this consensus as the starting framework when conducting rugby video analysis research. Which variables to use (if not all) depends on the objectives of the study. Furthermore, the intention of this consensus is to help integrate video data with other data (eg, injury surveillance).