Match workload and international travel associated with (ACL) injuries in professional women's football.

Women's football has grown in popularity, competitiveness and professionalism, increasing the demands placed on players and their injury risk. This study aimed to identify differences in the match workload and international travel between injured and non-injured professional women's footballers. The study was conducted as an observational, retrospective, case-control study over two football seasons (2021/2022 and 2022/2023) in four top-tier European women's football leagues. Fifty-eight professional women football players (81 injuries) formed the injury group and were matched with 81 elite women football players (162 non-injuries), from the same league, to form the control group. For each injury, cumulative match workload (minutes played, appearances, days between matches, rest) and international travel (distances, time, time zones crossed) were calculated over a 28-day period preceding the injury, for both the injured players and matched controls. The injured group had a higher number of instances of less than 5 days between matches compared to the controls (p = 0.03, effect size = 0.3, small). The anterior cruciate ligament injury group made more appearances (p = 0.09, effect size = 0.8, moderate), had more instances of less than 5 days between matches (p = 0.09, effect size = 0.8, moderate) and had less rest time (p = 0.12, effect size = 0.8, moderate) than the control group. No meaningful differences were observed between the hamstring injury group and the control group. These findings underscore the importance of careful consideration when developing match fixture schedules in elite women's football, particularly concerning the number of matches scheduled in a short period. Strategies to increase rest and recovery are recommended to safeguard players against injuries.

[Characterization of injuries among elite football players during a sports season in Burkina Faso: the 2019-2020 sports season]. / Caractérisation des blessures sur une saison sportive chez des footballeurs d'élite au Burkina Faso: cas de la saison 2019-2020.

Introduction: injuries are a major undesirable event in sportsmen's career and prevention depends on their characteristics. The aim of this study was to determine the characteristics of injuries suffered by elite footballers in Burkina Faso during the 2019-2020 sports season. Methods: we conducted a cross-sectional study among 160 players who were administered a questionnaire. Proportion and χ2 tests were used to calculate frequencies and determine associated factors, respectively. Results: a total of 157 injuries were recorded in 143 players (89.4%). Muscle injuries (45.85%) and sprains (30.6%) were common. The majority of injuries (52%) were of medium severity. The thigh (30%), ankle (26.5%) and knee (18%) were the most affected areas. The frequency of injuries was higher after physical contact than without physical contact with another player (69.5% versus 30.5; p = 0.009), during matches than during training (82% versus 28%; p = 0.003) and during the return leg than the first leg of the championship (58.5% versus 41.5%; p = 0.02). Conclusion: the frequency of injuries suffered by footballers during the 2019-2020 season was high. These injuries were mostly muscular and tendinous, and the lower limbs were mostly affected. They were associated with physical contact, matches and the return phase of the championship. To be effective, preventive measures should take these characteristics into account.

Risk and prevalence of Relative Energy Deficiency in Sport (REDs) among professional female football players.

A high prevalence of low energy availability (LEA) has been reported in female football players. This is of concern as problematic LEA may evolve into a syndromic pattern known as relative energy deficiency in sport (REDs). Given the difficulties in accurately assessing LEA, our study shifts emphasis to measurable indicators of REDs, serving as proxies for health detriments caused by LEA. The present cross-sectional study aimed to quantify the risk of REDs and to assess the prevalence of indicators indicative of the syndrome. 60 players (tiers 3 and 4) from three Norwegian football teams were analyzed as a single cohort but also stratified based on player position and menstrual status. The proportion of players at risk for REDs was 22%, that is, 17% with mild, 3% with moderate to high, and 2% with very high/extreme risk, respectively. The majority of the cohort (71%) presented with no primary indicators, while 20%, 7%, and 2% presented with one, two, and three primary indicators, respectively. Regarding secondary indicators, 57% had none, 33% had one, and 10% had two indicators. For associated indicators, 30% had none, 42% had one, 18% had two, 8% had three, and 2% had four indicators. Player position did not affect the prevalence of REDs indicators. Among noncontraceptive users (n = 27), secondary amenorrhea (AME) was reported by 30%. These findings indicate that health and performance teams should prioritize universal health promoting strategies rather than selective or indicative strategies. Particularly, focus on nutritional periodization to secure sufficient energy availability, mitigating the risk of problematic LEA and REDs should be addressed.

Antisocial behavior in football matches: Do changes in alcohol sales policy increase violent acts?

BACKGROUND: The violent behavior of football fans is constantly associated with their drinking habits. Aiming to reduce its impact, policy makers often ban the sales and consumption of alcohol beverages during matches. Nonetheless, there are few papers that empirically analyzed such relationship, and our paper aims to shed light on this question. METHODS: Out dataset comprises 4,560 matches from the first and second tiers of the Brazilian League, where 245 exhibited at least one antisocial behavior from fans. Ordered logistic regressions are used as method. RESULTS: Our empirical findings evidence that the sales of alcoholic drinks do increase the likelihood of severe antisocial behavior. We also observed a higher likelihood of violent cases when the home club loses its match as well as during crowded matches. CONCLUSIONS: We conclude that the change in the alcohol police in Brazil did show a significant association with the likelihood of antisocial behavior among football fans. However, since the magnitude of such effect is small, further research is needed to examine the potential benefits of this policy change.

Incidence and characteristics of COVID-19 in French professional football players during the 2020-2021 season.

OBJECTIVES: To describe the epidemiology of COVID-19 in French professional football players, and to compare the infection incidence with the general population across the first three waves. METHODS: During the 2020-2021 season, all professional football players (n = 1217) in the two primary French leagues underwent weekly testing for SARS-CoV-2 infection by nasopharyngeal PCR, in combination with rigorous infection control measures. RESULTS: Among all players, 572 (47%) tested positive at least once, with no COVID-19-related death or hospital admission. Monthly incidence estimates in players ranged from 1486 to 6731 per 100,000 individuals, i.e. 2-17 times higher than incidence estimates in the general population in France during the study period. CONCLUSION: Almost 50% of professional football players developed SARS-CoV-2 infection during the 2020-2021 season in France, with no severe complication.

Sport-related concussion return-to-play practices of medical team staff in elite football in the United Kingdom.

INTRODUCTION: This study explored sport-related concussion (SRC) return-to-play (RTP) behaviours and attitudes of medical team staff working in elite football in the United Kingdom. Usage and awareness of The Football Association (FA) guidelines, concussion education rates of players and coaching staff, and collection of baseline concussion assessments. Additionally, confidence in managing RTP post-SRC, perceived player under-reporting of symptoms, use of enhanced RTP pathways, and coaching pressure on RTP were investigated. METHODS: A cross-sectional questionnaire study was distributed online by organisations including or representing medical staff working in elite football in the United Kingdom. RESULTS: A total of 112 responses were gathered. High awareness rates of the FA guidelines were found (96%) with variable rates of player and coaching staff concussion education. Baseline concussion assessments were collected by 80% of respondents with 93% feeling very confident or confident in managing the RTP of a player with a SRC. 60% rarely or never experienced coaching pressure around player RTP, and 24% felt players always or very often under-reported symptoms to expedite their return. 90% had a moderate to high confidence in the Sport Concussion Assessment Tool-5 (SCAT-5) as a RTP decision tool, and 66% always or very often used an enhanced RTP pathway. CONCLUSION: Confidence in managing player RTP post SRC and use of enhanced RTP pathways were high, as was confidence in the SCAT-5 as a RTP decision tool. Respondents raised concerns around player under-reporting of symptoms to accelerate RTP post-SRC, and perceived coaching pressure around decision making.

A retrospective analysis of all-cause and cause-specific mortality rates in French male professional footballers.

This study retrospectively compared all-cause and cause-specific mortality in French male professional football players with data from France's national population. Altogether, 6114 individuals born in Metropolitan France or in one of its overseas territories who played at least one competitive match in France's professional football championships between January 1, 1968 and December 31, 2015, were identified and followed up for vital status obtained from a national reference database until December 31, 2015. Data on all-cause and cause-specific mortality were subsequently compared to the expected number of deaths for the national population after standardization for the year, age, and sex. Ratios between observed and expected deaths provided standardized mortality ratios (SMR) along with 95% confidence intervals (95% CI). Linear trends were investigated using the Poisson trend test. Altogether, 662 player deaths were observed. All-cause mortality overall was lower than that of the national population (SMR: 0.69, 95% CI 0.64-0.75). An excess of deaths from dementia was observed in the players (SMR: 3.38, 95% CI: 2.49-4.50) whereas mortality from diseases of the nervous (SMR: 0.64, 95% CI: 0.35-1.08) and cardiovascular systems (SMR: 0.82, 95% CI: 0.70-0.96), and cancer (SMR: 0.67, 95% CI: 0.58-0.76) was lower. Lower overall mortality and that owing to common cardiovascular and cancer-related diseases were reported in French professional football players compared to France's national population. In line with previous studies, however, excess mortality from dementia was observed in the players. Career length was not associated with all-cause or cause-specific mortality. Prospective matched-cohort studies are necessary to identify the neurologic impact of participation in professional football.

Soccer in the time of COVID-19: 1 year report from an Italian top league club, March 2020-February 2021.

We report the events of an Italian top league soccer club that took place in 1 year (from March 2020 to February 2021) at the time of coronavirus disease 2019 (COVID-19) pandemic. In early March 2020, just before sport competitions were called off due to the national lockdown in Italy, the team, which included 27 players and 26 staff at the time, faced a COVID-19 outbreak, with 16 confirmed and seven probable cases, including three staff members who had to be hospitalised. In May 2020, at the resumption of the training sessions, a high prevalence of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G positivity (35/53, 66%) was detected among the members of the group. In the following months, sport activities were organised behind closed doors with stringent risk mitigation procedures in place. As of February 2021, only two new cases of SARS-CoV-2 infection were detected within the group, against more than 3500 nasopharyngeal swabs and 1000 serological tests.

Simple and reliable protocol for identifying talented junior players in team sports using small-sided games.

We designed and tested a protocol for measuring the performance of individuals in small-sided soccer games. We tested our protocol on three different groups of youth players from elite Brazilian football academies. Players in each group played a series of 3v3 games, in which individuals were randomly assigned into new teams and against new opponents for each game. We calculated each individual's average individual goals scored, goals scored by teammates, goals conceded, and net team goals per game. Our protocol was consistent across days and repeatable across groups, with intraclass correlation coefficients (ICCs) of 0.57-0.69 for average net goals per game across testing days. Players could achieve high success by scoring goals or ensuring their team concede few goals. We also calculated the first and second dimension of a principal component analysis based on each player's number of goals scored, goals scored by teammates, and number of goals conceded per game. Players that were overall high performers had higher PC1 scores, while PC2 scores represented the type of contribution made by a player to overall performance. Positive PC2 values were indicative of high number of individual goals while negative values were associated with more goals from teammates and fewer conceded goals. Our design allows coaches and scouts to easily collect a robust metric of individual performance using randomly designed, small-sided games. We also provide simulations that allow one to apply our methodology for individual talent identification to other small-sided games in any team sport.

Effectiveness of the FIFA 11+ Referees Injury Prevention Program in reducing injury rates in male amateur soccer referees.

OBJECTIVE: The Fédération International de Football Association (FIFA) 11+ Referees Injury Prevention Program (FIFA 11+ Referees Program) is a structured warm-up program specially designed to prevent injuries in soccer referees. However, its effectiveness has yet to be fully documented in the literature. Therefore, the purpose of this study was to investigate the effectiveness of the FIFA 11+ Referees Program in reducing injury rates among soccer referees. METHODS: A randomized controlled trial was conducted. Two hundred male amateur soccer referees (mean ± SD age, 31.6 ± 4.1 years) participated in this study. Participants were randomly allocated to the experimental and control groups. The experimental group performed the FIFA 11+ Referees Program as a warm-up during training sessions at least twice a week, and the control group performed their usual warm-ups. The participants were followed up for one season. The outcome measures were the incidence of overall injury, initial injury, recurrent injury, injury mechanism, and injury severity (primary), and the rate of adherence to the intervention program (secondary). RESULTS: A total of 24 injuries were reported among 100 referees in the control group in 16 606 h of exposure (1.45 injuries/1000 exposure h), and a total of nine injuries were reported across 100 referees within the experimental group in 17 834 exposure h (0.50 injuries/1000 exposure h). The Injury Risk Ratio (IRR) was 0.35 (95% CI 0.26-0.45). CONCLUSION: The results indicated that the FIFA 11+ Referees Program effectively reduced injuries in the experimental group by 65% compared to the control group.

Motor performance is not related to injury risk in growing elite-level male youth football players. A causal inference approach to injury risk assessment.

OBJECTIVE: To identify the causal relation between growth velocity and injury in elite-level youth football players, and to assess the mediating effects of motor performance in this causal pathway. DESIGN: Prospective cohort study. METHODS: We measured the body height of 378 male elite-level football players of the U13 to U15 age categories three to four months before and at the start of the competitive season. At the start of the season, players also performed a motor performance test battery, including motor coordination (Körperkoordinationstest für Kinder), muscular performance (standing broad jump, counter movement jump), flexibility (sit and reach), and endurance measures (YoYo intermittent recovery test). Injuries were continuously registered by the academies' medical staff during the first two months of the season. Based on the causal directed acyclic graph (DAG) that identified our assumptions about causal relations between growth velocity (standardized to cm/y), injuries, and motor performance, the causal effect of growth velocity on injury was obtained by conditioning on maturity offset. We determined the natural indirect effects of growth velocity on injury mediated through motor performance. RESULTS: In total, 105 players sustained an injury. Odds ratios (OR) showed a 15% increase in injury risk per centimetre/year of growth velocity (1.15, 95%CI: 1.05-1.26). There was no causal effect of growth on injury through the motor performance mediated pathways (all ORs were close to 1.0 with narrow 95%CIs). CONCLUSIONS: Growth velocity is causally related to injury risk in elite-level youth football players, but motor performance does not mediate this relation.

Injuries in youth football and the relationship to player maturation: An analysis of time-loss injuries during four seasons in an English elite male football academy.

A better insight into injuries in elite-youth football may inform prevention strategies. The purpose of this prospective cohort study was to investigate the frequency, incidence, and pattern of time-loss injuries in an elite male football academy, exploring injuries in relation to age and maturation status. Across four consecutive playing seasons, playing exposure and injuries to all academy players (U'9 to U'21) were recorded by club medical staff. Maturation status at the time of injury was also calculated for players competing in U'13 to U'16 aged squads. Time-loss injury occurrence and maturation status at time of injury were the main outcome measures. A total of 603 time-loss injuries were recorded, from 190 different players. Playing exposure was 229 317 hours resulting in an overall injury rate of 2.4 p/1000 h, ranging from 0.7 p/1000 h (U'11) to 4.8 p/1000 h (U'21). Most injuries were traumatic in mechanism (73%). The most common injury location was the thigh (23%), and the most common injury type was muscle injury (29%) combining to provide the most common injury diagnosis; thigh muscle injury (17%). In U'13-U'16 players, a higher number of injuries to early-maturing players were observed in U'13-U'14 players, while more injuries to U'15-U'16 players occurred when classed as "on-time" in maturity status. Maturation status did not statistically relate to injury pattern; however, knee bone (not-fracture) injuries peaked in U'13 players while hip/groin muscle injuries peaked in U'15 players.

Resuming professional football (soccer) during the COVID-19 pandemic in a country with high infection rates: a prospective cohort study.

OBJECTIVES: The risk of viral transmission associated with contact sports such as football (soccer) during the COVID-19 pandemic is unknown. The aim of this study was to describe the infective and immune status of professional football players, team staff and league officials over a truncated football season resumed at the height of the COVID-19 pandemic in a country with high infection rates and to investigate the clinical symptoms related to COVID-19 infection in professional football players. METHODS: Prospective cohort study of 1337 football players, staff and officials during a truncated football season (9 weeks) with a tailored infection control programme based on preventive measures and regular SARS-CoV-2 PCR swab testing (every 3-5 days) combined with serology testing for immunity (every 4 weeks). Clinical symptoms in positive participants were recorded using a 26-item, Likert-Scale-based scoring system. RESULTS: During the study period, 85 subjects returned positive (cycle threshold (cT) ≤30) or reactive (30

Mortality of Spanish Former Elite Soccer Players and Coaches.

We analyzed whether male Spanish elite soccer players live longer than the general population. Secondly, we compared their mortality with a cohort of soccer players who continued working as soccer elite coaches after retirement. Using age and calendar-date adjusted life tables, we analyzed the mortality hazard ratio of 1333 Spanish male players born before 1950, and who played in elite leagues from 1939, compared with the Spanish population. Using Cox proportional hazards model we compared their mortality with a cohort of 413 players who continued as coaches. Players showed significantly lower mortality than the general population, but this advantage decreased with advanced age, disappearing after 80 years. Coaches showed a similar pattern. Comparing players versus coaches, date of birth and years as professional were associated with survival, but debut age and player position were not. Unadjusted median survival time was 79.81 years (IQR 72.37-85.19) for players and 81.8 years (IQR 74.55-86.73) for coaches. Kaplan-Meier estimator adjusted for covariables showed no difference between cohorts (p=0.254). In conclusion, former Spanish male players showed lower mortality than the general population, but this effect disappeared after 80 years of age. Continuing their career as coaches after retirement from playing did not confer major benefits.

Is impaired coordination related to match physical load in footballers with cerebral palsy of different sport classes?

Impaired coordination is a characteristic feature in cerebral palsy (CP) football players. This study aimed to determine the relationships of three coordination tests with match physical load during competition of para-footballers from different sport classes. Records from 259 para-footballers from 25 national teams were obtained in four international competitions held in 2018 and 2019. The three coordination tests were conducted prior to competition (i.e., rapid heel-toe, side-stepping, and split jumps), and physical match load was recorded by GPS devices during the real game: i.e., maximum/mean, total distance, distance covered at different speed zones, number of accelerations/decelerations at different intensities, and player load. FT1 and FT3 players have the lowest and highest performance in all the coordination tests, respectively, but inconclusive between-groups differences were obtained (p=0.022‒0.238). Split jumps and side-stepping tests are associated with the performance of moderate and high accelerations during competition (r = -0.20‒0.71; p<0.01). Significant correlations (r = 0.36‒0.71; p<0.01) were obtained between all the coordination measures. Coordination tests better discriminate those with more severe impairments and some evidence for the validity of the new CP football sport classes is provided. Further research is necessary to identify the portion of the variance in sports performance that coordination explains.

Playing Non-Professional Football in COVID-19 Time: A Narrative Review of Recommendations, Considerations, and Best Practices.

The coronavirus disease (COVID-19) pandemic in 2020 resulted in widespread interruption of team sports training and competitions. Our aim was to review the recommendations and best practices in return to play in non-professional football after activity lockdown. The authors searched two electronic databases (PubMed, Web of Science) to extract studies published before September 15 2020. Twenty studies explained recommendations, considerations, or best practices in return to play in football, and all of them were clustered into three groups: (1) training load management (n = 10), (2) medical recommendations (n = 9), and (3) recovery related issues (n = 5). The way to establish a progression in training process should be based on training load management and managing the number of stimuli per time. Following the studies, this training process should be divided into three phases: phase 1-physical distancing should be maintained; phases 2 and 3-group training should start. Medical considerations were clustered into different groups: general, pre- and post- training, during training, education, planning to return to competition, and suggestions for post confinement weeks. In particular, social issues, strict hygiene questions, and continuous PCR testing should be considered in return to play over football season. Finally, since a correlation has been found between high-intensive training loads and immunoglobulin A, nutritional and lifestyle recovery strategies should be performed. Moreover, since immunosuppression has been related to congested schedules (<72 h between matches), football federations should avoid this situation.

The incidence and characteristics of purposeful heading in male and female youth football (soccer) within Australia.

OBJECTIVES: To quantify the incidence and characteristics of purposeful headers and unintentional head impacts during male and female youth football (soccer) games in Australia. DESIGN: Cross-sectional observational study. METHODS: Ten match-videos (total n=110) per playing age (under 13-20 males; under 13-17 females) from the 2019 National Premier League season were coded for purposeful headers and unintentional head impacts. Total headers and head impacts as well as incidence rate (IR) per 1000 match-hours for different match characteristics were calculated. RESULTS: Purposeful headers accounted for 99% (n=4615, IR:1618) of total head impacts. The IR of purposeful headers per 1000 match-hours was highest for under-15 males (IR:2117) and under-17 females (IR:2090) followed by under-20 males (IR:1761). Midfielders completed the most headers in all female age groups (mean IR:713) and under 13-14 males (mean IR:891), with defenders completing the most headers in under 15-20 males (mean IR:760). Heading duels accounted for 16% of total headers with most headers performed during free play (68%), throw-ins (15%), free kicks (12%) and corner kicks (5%). Only 57 head impacts (IR:20) were coded as unintentional head impacts resulting from being struck by the ball or opponent body part with 4 (IR:1.4) requiring medical attention. CONCLUSIONS: Heading is a complex skill. Given the propensity of youth players of all ages to purposefully head the ball, consideration should be given to coaching heading technique based on specific game scenarios for their playing position and age group. The findings of this study can be used to inform heading guidelines.

Injury prevention knowledge, beliefs and strategies in elite female footballers at the FIFA Women's World Cup France 2019.

OBJECTIVES: This study assessed knowledge, beliefs and practices of elite female footballers regarding injury prevention. METHODS: A survey was sent to players participating in the FIFA Women's World Cup France 2019. Questions covered three injury prevention domains: (1) knowledge; (2) attitudes and beliefs; (3) prevention practices in domestic clubs. Additionally, ACL injury history was assessed. RESULTS: Out of 552 players, 196 women responded (35.5%). More than 80% of these considered injury risk to be moderate or high. Players listed knee, ankle, thigh, head and groin as the most important injuries in women's football. The most important risk factors identified were low muscle strength, followed by poor pitch quality, playing on artificial turf, too much training, reduced recovery and hard tackles. In these elite players, 15% did not have any permanent medical staff in their domestic clubs, yet more than 75% had received injury prevention advice and more than 80% performed injury prevention exercises in their clubs. Players identified the two most important implementation barriers as player motivation and coach attitude. Two-thirds of players used the FIFA 11+ programme in their clubs. CONCLUSIONS: This diverse group of elite players demonstrated good knowledge of risk level and injury types in women's football. Of the risk factors emphasised by players, there was only one intrinsic risk factor (strength), but several factors out of their control (pitch quality and type, training volume and hard tackles). Still players had positive attitudes and beliefs regarding injury prevention exercises and indicated a high level of implementation, despite a lack of medical support.

Mechanisms explaining the birthplace effect for male elite football players.

Earlier research shows that wide regional variations exist in the success of athletes' talent development but is divided with respect to the role of urbanity: both low and high urbanity have been identified as settings that contribute to the presence of talent hotspots. In this article, we intend to provide more insight into the role of urbanity in talent development in Dutch football. We used public data on the regional background of male elite players (N = 825) and combined this with public data on municipal characteristics from Statistics Netherlands and other sources: urbanity, football participation, instructional resources and population composition effects (migration background and income of inhabitants). Linear regression analysis showed that football participation, the proportion of non-western migrants and median income predict "talent yield", i.e., the proportion of young people that reach an elite level in a municipality. Urbanity does not have an independent influence when the proportion of non-western migrants in the municipality is taken into account. The presence of instructional resources does not have an independent influence. The results suggest that characteristics of the built environment, such as indoor and outdoor play opportunities, may be less influential in talent development than previously assumed.

Long-term influence of technical, physical performance indicators and situational variables on match outcome in male professional Chinese soccer.

This study aimed to determine whether the role of technical, physical performance indicators and situational variables in determining match outcome has varied from a long-term analysis (seasons 2012 to 2017) of the Chinese Soccer Super League (CSL). The sample included 1,429 matches where 17 technical performance-related indicators, 11 physical performance-related indicators and two situational variables (match location and quality of opposition) were analysed. Three binary logistic regression models (inclusion of different variables) were used to measure the level of association between factors and match outcome over the six seasons studied. Results of models 1 and 2 revealed that shots on target, possession, total distance in ball possession, total distance out of ball possession, and match location exerted a decreased influence on winning the matches from 2012 to 2014 seasons. However, these indicators play a more important role in winning matches from 2014 to 2017 seasons. Additionally, the quality of opposition has a continuously increased negative effect on the match outcome. In model 3, more variables, such as high-speed distance, high-speed out of ball possession, had a meaningful influence on winning the match. These results provide valuable information about performance indicators and situational variables on winning the matches from a long-term approach.