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Due to its competitive nature, youth sports may provide an environment that invites the display of negative parenting behavior and exposes children to adults outside of their own household. This study aimed to quantify the frequency of negative parent and spectator behavior at youth sporting events and compare incidences across different sports and age ranges. Investigators attended baseball, basketball, soccer, and football events in Central Oʻahu, Hawaiʻi for children ages 6 to 10 years. Recorded spectator behaviors included alcohol use, smoking, swearing, and negative language (such as threats and violent language). Negative behaviors were reported at a majority (68%) of events. The 95% confidence intervals of the means (95% CIM) for all negative behaviors observed were overlapping, and we were not able to demonstrate statistically significant differences between the 4 sports. The lack of significance between sports may be due to the younger-player-age group, small sample size, and time of events. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the weekly accumulative external load according to their participation in the previous match and the following match in three teams of different categories belonging to a football club. Sixty football players participated, belonging to the under-23 (U23, n: 20), U21 (n: 22) and U19 (n: 18) teams. Players were monitored by global positioning system devices during all training sessions and official matches. For the accumulative weekly load (from Monday to Sunday), the following external load variables were used: total distance covered (TD, m), distance covered at different speed thresholds (>14.0, >18.0, >21.0 and >24.0 km·h−1), the number of moderate-high intensity accelerations (ACC: >2 m·s−2, n) and decelerations (DEC: <−2 m·s−2, n), the player load (PL, arbitrary units, au) and the acceleration load (Aload, au). Players were grouped according to their participation in the previous and next matches: starter and starter (SS, when the player was a starter in both the previous and the following matches), starter and non-starter (SN), non-starter and starter (NS), and non-starter and non-starter (NN). This study revealed that NS and SS groups had a higher absolute and relative accumulative weekly load for the global indicators (Aload, PL and TD) in the three teams than NN and SN (range of ES: 0.1–3.4). This information would allow coaches to refine the required stimulation regarding players' role in the team based on the player's participation in the previous and next match. [ABSTRACT FROM AUTHOR]

This article presents the findings of a season-long investigation of video-based coaching (VBC) practices in an English youth soccer academy. During the period of fieldwork, the lead author immersed themselves within the academy setting, in which they observed 22 VBC sessions and also day-to-day interactions between coaching staff relating to these activities. In addition, 18 interviews were conducted with 5 coaching staff, totalling 8 h of in-depth interview data. The fieldnotes and interview transcripts were iteratively analysed, utilising Goffman's dramaturgical writings and Groom et al.'s grounded theory of VBC. Our analysis produced two overarching themes. These were (a) how the coaching staff concealed that VBC sessions were principally designed to develop 'high priority' players and (b) how the coaching staff purposefully withheld critical thoughts and feelings about their player's performances, preferring instead to strategically focus on the provision of positive messages during VBC sessions. These findings contribute to the limited investigation of this aspect of coaching and demonstrate the importance of educating coaches to acknowledge how VBC can be influenced by and used to respond to workplace demands and expectations. [ABSTRACT FROM AUTHOR]

Female soccer players report that the menstrual cycle (MC) can negatively impact sporting performance, with barriers identified in communicating their MC experiences to coaches and support staff. Whilst research is growing, there are few studies exploring the coaching staff perspective in soccer, and none from those at the youth level. The aim was to explore soccer coaches' awareness, perceptions and experiences of the MC and the perceived impact on performance. Thirteen coaches (female n = 4; male n = 9, aged 33 ± 9 years) from Scottish elite adult and youth soccer participated in individual semi-structured interviews (average interview time 39 ± 11 min). Interviews were audio recorded and transcribed verbatim, with reflexive thematic analysis (RTA) performed. RTA generated three key themes from 232 meaning units: environment and culture, coach–athlete dynamic, and coach support and education. Coaches perceived a societal culture of the MC being hidden, or taboo, with similar barriers noted within the club environment. Coaches were often embarrassed to discuss the MC with players and believed players were embarrassed. Communication differed depending on the coach–athlete relationship, with trust and familiarity cited as improving comfort in communication. Coach awareness and understanding of the MC both generally and within a sporting context influenced their perceived ability to communicate and support players. Findings highlight the need to support coaches by providing MC education, and practical guidance on how to support players' health and wellbeing. Improved confidence in communication should allow players to feel supported and normalise conversations about the MC. [ABSTRACT FROM AUTHOR]

The nurturing of young players in youth academies is seen as an important step on the way to becoming a full professional in the sport of soccer. This longitudinal multi-study investigation, spanning 2009 to 2021, analysed the career paths of Spanish academy soccer players. It consisted of three studies investigating players' transition from academy to professional status and the identification of technical skills and psychological traits which could distinguish future professionals from amateurs. The sample involved 198 male academy soccer players (aged 13.5–17.9) from two Madrid-based professional clubs. Study 1 assessed the outcomes of these players a decade after their academy-level evaluations. Studies 2 and 3 focused on the subgroup of 85 players whose playing status could be verified a decade later. Results showed that 12 players (6.1%) progressed to full-time professional soccer. Of these 12, just 7 reached Spain's highest professional league within 10 years of their final academy tests. Significant differences favouring professional players were observed in the trait of 'self-confidence', 'ball reception', 'dribbling forward with the ball' and coaches' global technical assessments. In conclusion, the chances of academy soccer players achieving professional status are low. Accordingly, providing more developmental opportunities before deselection is crucial to maximise player potential. Coaches could prioritise players' self-confidence and ball control to increase the conversion rate of academy players to professional status. Furthermore, recruitment of players who are already strong in these attributes could also improve the productivity of talent development pipelines. [ABSTRACT FROM AUTHOR]

This study aimed to describe and analyse the disciplinary sanctions received by grassroots soccer coaches in the Valencian Community (Spain) over five seasons. Specific objectives included determining the influence of format (8-a-side or 11-a-side), age (U7, U9, U11, U13, U15, and U18), sex category (male or female), and sanction severity (mild [one to four matches] or serious [five matches to a full season]). A study was conducted based on referees' records from 275,844 games played in 1401 league competitions during five subsequent seasons between 2014 and 2019 in Valencia (Spain). A total of 3563 sanctions were recorded by matchday referees, with the majority being minor offences (92.93%) and most being imposed on 11-a-side soccer coaches (87%). The most frequent reasons for sanctions pertained to protests to referees (28%); dismissal due to double reprimands (26.40%); contemptuous and inconsiderate attitudes towards referees, including insults and threats (19.53%); and direct sending-offs (8.84%). Significantly more mild sanctions were found than serious ones, with more sanctions emerging in the 11-a-side soccer than in the 8-a-side soccer and the men's category compared to the women's category. Finally, we found significantly more sanctions in the U18 men's category compared to all other younger age categories and in the U15 men's category compared to the U7, U9 and U9-U11 female categories (p <.05). [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of game formats on the running and technical–tactical performance of young soccer players, as well as on players' dynamics of spatial occupation during competitions. Eleven players of a U-11 team (11.10 ± 0.39 years old) participated in three competitions specifically designed to analyze the impact of different game formats: 5vs5 (F-5), 7vs7 (F-7) and 11vs11 (F-11). Players' running performance and dynamics of spatial occupation were analyzed using the GPSs devices from WIMU PRO™ devices (10 Hz). Players' and team's technical–tactical performance was also analyzed using the Team Sports Assessment Procedure (TSAP) and the Offensive Sequence Characterization System (SCSO), respectively. It was observed that the teams tended to adopt a less direct style in the F-11 (LpW : F7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = 0.002), with a lower rate of spatial exploration (F-7 vs. F-11 p = 0.001 and &&F-5 vs. F-11 p = 0.001) and lower running demand (Sprint : F-7 vs. F-11 p = 0.001 and F-5 vs. F-11 p = 0.014; HSR : F-7 vs. F-11 p = 0.001 and F-5 vs. F-11 p =.001). In addition, the F-11 allowed the players to have less involvement during the match (F-7 vs. F-11 p = 0.003; F-5 vs. F-11 p = 0.001), as well as a lower technical–tactical performance (F-7 vs. F-11 p =.003 and F-5 vs. F-11 p =.005). Our results highlight the importance of adjusting the game formats used in youth competitive environments to players' intrinsic dynamics. [ABSTRACT FROM AUTHOR]

Objective: Variation in training load is consistently demonstrated within weekly microcycles in soccer, yet less is known of load variations between the same weekday sessions across different microcycles. Our study aim was to examine between-microcycle variability in key measures of external training load. Methods: Thirty-seven professional soccer players participated in this observational study which took place across the clubs' initial 8-week in-season mesocycle of the 2022/23 season. During this mesocycle, each 1-week microcycle consisted of four distinct classifications of training session (Matchday (MD)-4, MD-3, MD-2, and MD-1, and one match (Saturday). External load data (total distance, high-intensity (>5.5 m.s) distance, high-intensity accelerations (>3 m/s2), and percentage (%) of maximal speed attained) were collected across 564 training sessions (MD-4 = 123, MD-3 = 148, MD-2 = 130, MD-1 = 163). Data were analysed with mixed linear modelling. Results: When compared to the first microcycle, substantial week-to-week variation was evident for each of the four training session classifications, ranging from 1244 m to 2248 m for total distance, 80 m to 197 m for high-intensity distance, 11 to 25 for high-intensity accelerations, and 10.2 percentage points to 15.4 percentage points for % maximal speed. Conclusion: Our data show that despite training sessions having a consistency of planned training stimulus across an 8-week mesocycle, external load varied between microcycles. Nevertheless, within-player variability on the same day relative to matchday indicated a more consistent stimulus for key training variables relevant to specific training days. [ABSTRACT FROM AUTHOR]

This study identified which key performance indicators that predict the probability of winning are similar and specific for the top CONMEBOL and UEFA leagues. The analysis covered 12,289 games from the 2017/2018 to 2021/2022 seasons, excluding draws to focus on decisive results. Performance metrics were extracted using the InStat Scout® web platform, evaluating 55 offensive and defensive performance variables from the CONMEBOL and UEFA leagues. For data analysis, binary logistic regression was performed with the Forward Stepwise method. 14 similar predictive variables were identified between the CONMEBOL and UEFA leagues. We also identified 6 win-predictor variables specific to CONMEBOL, 2 win-predictor variables specific to UEFA, and 1 contextual variable that was predictive of victory for the CONMEBOL and UEFA leagues. The KPIs that are associated with an increased likelihood of winning games were identified. These include offensive actions, such as creating scoring chances, entering the final third of the opponent's field, shooting on goal, and being effective in counterattacks, converting penalties, and direct free kicks and making important passes and passes. For defensive actions, it was found that fouls, recoveries, possession interceptions, and low block defensive pressures are also associated with an increased likelihood of winning in the five main CONMEBOL and UEFA leagues. Particularly, for CONMEBOL leagues, counter-attacking actions, ball possession (%), free-kicks and efficiency for high pressing can also be associated with increased probability of winning. Specific to UEFA leagues, advancing actions down the left flanks and efficiency for team pressing are associated with increased probability of winning. [ABSTRACT FROM AUTHOR]

The purpose of this study was to characterize critical speed (CS) models for summarizing high-resolution speed-duration profiles from GPS tracking data obtained from soccer players. GPS data from 15 male NCAA Division I soccer players were collected during practices and games over a 6-week period. Moving averages of the speed data were computed for each file for duration windows spanning 0.1 to 600 seconds at 0.1-second resolution. Speed-duration profiles for each session and for the entire sampling period ("global") were generated for each player by selecting the maximal mean speeds for each duration. Four models were fit to the profiles: the two-parameter CS (CS2) model, the three-parameter CS (CS3) model, the omni-domain speed-duration (OmSD) model, and the five-parameter logistic (5PL) model. The 5PL, CS3, and OmSD models exhibited similar goodness of fits, and all outperformed the CS2 model. Similar CS estimates were obtained for each model, whereas maximum speed (S max) estimates were lower for OmSD compared to the 5PL. Players exhibited a range of parameter values for CS, D ′, and S max. S max and CS estimated from session-specific speed-duration profiles were on average higher for games compared to practices. We conclude that CS models are useful for empirically describing speed-duration profiles and for assessing peak running demands for soccer practices and games. The proposed approach could help coaches design practice activities to better mimic game demands. [ABSTRACT FROM AUTHOR]

The purpose of this study was threefold: (1) to compare the engagement in various types and amounts of soccer activities during childhood and adolescence between Brazilian and Spanish elite youth soccer players; (2) to test what talent development pathway characterizes youth development in elite soccer in Brazil and Spain and (3) to compare the practice structure between elite youth soccer in Brazil and Spain. Participants were 131 U-18 elite male soccer players from Brazil (n = 68) and Spain (n = 63) competing in the national league. The Participant History Questionnaire was used to measure the soccer activities undertaken by players. Developmental activities were analyzed for two age periods: childhood (6–12 y/o) and early adolescence (13–15 y/o). In Spain, players started their involvement in practice and competition in soccer earlier compared to Brazilian players (p <.05). Brazilian players were more involved in structured activities, such as practice in soccer and futsal, and participated in a greater number of sports in childhood and early adolescence (p <.05). We found a very similar percentual practice structure (individual, pair, drills, group tactics and collective tactics activities) between Spain and Brazil, although Brazilian players accumulated a greater practice volume. It is concluded that Spanish and Brazilian U-18 elite youth male soccer players were differentiated by their milestones in soccer and their engagement in practice activities during childhood and early adolescence. Talent development pathway of male soccer players in Spain was characterized by the early engagement pathway, while the Brazilian system was characterized by the specialized sampling model. [ABSTRACT FROM AUTHOR]

Background: Monitoring of training tasks allows coaches to have a better knowledge of the loads applied to their players. Objectives: The aim of this study was to analyze the variations in external load in small-sided games (SSGs) with young players U-12, U-15, and U-23 and compare the external load between age categories in each of the SSGs. Methods: A group of 24 male soccer players performed five consecutive different formats of four vs. four SSGs composed of 3 minutes of play/rest. GPS devices were used during the tasks (WIMU PRO™). The data were analyzed using IBM SPSS Statistics 28.0, using descriptive statistics, graphical statistics, and ANOVA to compare the results between SSGs and between age groups. Results: The increase in field areas promotes the increase of distance (DIST) covered and the high metabolic load distance (HMLd), with and without a goalkeeper (GK). The SSGs with GK recorded fewer PL values compared to SSGs without GK. In the U-12 and U-15 age groups, GK use promotes more acceleration (AC) and deceleration (DEC) of high intensity (>3 m/s2). The results also show that the larger areas are promoters of high-speed running (HSR). Age influences some external load variables (DIST, AC, DEC, HMLd) in the game formats studied. Conclusions: The SSG formats analyzed using GK are promoters of high-intensity neuromuscular activity. Larger areas promote more high-speed displacement. Age is an influence on the external load in different SSGs. [ABSTRACT FROM AUTHOR]

This study aimed to compare the perceptions of boys and girls regarding their gender-specific talent development environments (TDEs) in state-level youth soccer. Seventy-one players (girls, n = 35; boys, n = 36) aged 11–18 years completed the Talent Development Environment Questionnaire (TDEQ-5), Sports Motivation Scale (SMS-6), Coach-Athlete Relationship Questionnaire (CART-Q), and Self-Efficacy and Outcome Expectancies (SEOE) of strength training questionnaire. Mann–Whitney U tests and Hedges's g effect sizes were used to identify group differences. Boys scored higher for TDEQ-5 subdimensions: long-term development focus, alignment of expectations, and holistic quality preparation. For the CART-Q, boys perceived greater coach commitment, whilst girls perceived greater coach complementarity. The SMS-6 results suggested higher amotivation among girls and higher external regulation and introjected regulation among boys. Finally, boys reported greater self-efficacy and outcome expectancies related to strength training. Overall, the findings reveal significant disparities in boys' and girls' perceptions of their TDEs. Whilst these findings provide a more nuanced understanding of youth soccer TDEs, further research is necessary to identify the critical factors for effective athlete development regardless of gender, or with more informed considerations of gender. Stakeholders should consider the unique constraints and resources specific to their TDE to determine which strategies may best impact their functionality. [ABSTRACT FROM AUTHOR]

Forced migration is one of the most pressing crises of our lifetime. Of the millions forced to migrate, many come to know the brutality of state-managed migration that habitually denies asylum seekers and places substantive restrictions on refugees who have been resettled. Sociologists of sport and leisure have examined the sporting experiences of refugees through an intersectional lens, foregrounding how displacement and resettlement are differently lived and negotiated across overlapping power structures and markers of gender, sexuality, ethnicity, religion, and legal status. Through a participatory and collective photovoice project, this article explores the experiences of an all-Afghan soccer team that played in a social, co-ed soccer league in the spring of 2022, just after they arrived in Edmonton, Alberta, Canada. In photovoice narratives and subsequent interviews, team members underlined many of the barriers they faced as they navigated the formal and informal rules and dominant norms of this seemingly inclusive sports landscape. In doing so, they revealed some of the limits of official discourses of Canadian multiculturism, which rarely accommodate more significant forms of difference, and which reproduce racial and ethnic hierarchies that powerfully discipline newcomers who are encouraged to embrace their precarious status as model minorities. [ABSTRACT FROM AUTHOR]

This paper draws on original research from a larger study of racism and Islamophobia online around football, particularly a set of interviews with staff at English football clubs whose responsibility is to manage social media. We use that information alongside our reflections on "platformed racism" to appraise how expressions of racism on social media differ from those in and around the grounds, and how clubs and others in football contest them. This involves a consideration of three themes commonly identified by those speaking on behalf of the clubs: The triggers that ignite racist posts; the partnerships necessary to counter them; and their proposed solutions. Hence this is not just a cue for a collective wringing of hands, but an effort to point the way forward. [ABSTRACT FROM AUTHOR]

The quantitative relationship between kicking motion and ball behaviour can be easily explained by detecting the impact point and foot posture. In previous studies, the impact point of a kicking foot was difficult to capture using visual tracking. Thus, a virtual surface modelling technique was applied in this study to clarify the differences in the three-dimensional foot speed, impact point and foot posture between straight, curve, and knuckle kicks in soccer, as well as the relationship between the kick motion and ball rotation. An optical three-dimensional motion capture system (VICON) was used to record the kicking motion. The impact points of the straight, curve, and knuckle kicks were found to be centrally located in the instep area, at a lower (more downwards) inside area, and at the medial area between the instep and inside areas of the kicking foot, respectively. Moreover, an impact with a greater 'swing vector deviation angle (relative to the direction from the impact point to the centre of gravity of the ball)' is necessary for ball rotation. The impact point detection method employed in this study can be applied to other ball impact estimations beyond soccer kicks. [ABSTRACT FROM AUTHOR]

In contemporary research literature, inconsistencies regarding the validity and reliability of different brands of global positioning systems (GPSs) have been reported regarding the positioning of GPS units on athletes. For this reason, the present work investigates the validity and reliability of the measurements of GPS units placed at different locations. Thirty-two amateur soccer players (age: 21.18 ± 3.16 years; height: 175 ± 8.03 cm; body mass: 74.21 ± 4.85 kg) voluntarily participated in the current study. Participants were asked to complete a team sport simulation cycle (TSSC). During the tests, two GPS units were placed between the shoulder blades and on the chest of each athlete. Data from Polar Team Pro GPS units at both locations on the body, previously measured test area distance, and a radar gun (the gold standard) were compared to determine validity. The reliability of GPS units in measuring maximum speed is moderate (CV = 9.77–9.08, ICC = 0.23). The reliability of GPS units in measuring total distance is good (CV = 4.43–9.39, ICC = 0.15). The reliability of GPS units in measuring distance covered is poor (CV = 17.51–35.37). The measurements of total distance covered, and maximum speed recorded by the chest and back GPS units are not valid (Max speed = GPS chest-radar gun; R 2 = 0.075, GPS back-radar gun; R 2 = 0.106, total distance = GPS chest-1200 m; R 2 = 0.003, GPS back-1200 m; R 2 = 0.097). Consequently, it can be said that 10-Hz Polar GPS sensors have good reliability for measuring total distance when placed on the chest and moderate reliability for measuring peak speed when placed on the chest and back; however, they have poor reliability at both positions for evaluating distances at different running speeds. [ABSTRACT FROM AUTHOR]

The occurrence of squad rotation in football and its effect on team performance in terms of points have not been comprehensively studied in football performance analysis literature. This study deploys a data-driven approach to examine the occurrence of squad rotation across English, French, Italian and Spanish leagues over multiple seasons. It aims to establish the relationship observed between average squad rotations in starting lineups and end-of-season points. A total of 16,720 matches dating from the 2010/11 to 2021/22 seasons were analysed for average rotations in each team involved and the respective team's end of season points, alongside contextual information such as injury and logarithmic market value. A linear mixed-effects model was used to study this relationship, with each variable as well as interaction of variables being analysed for fixed effects. The results show that a significant relationship exists between team success, average rotation of the team per match and market value of the team, while no significant effects are found for injuries. The results describe how universally deploying squad rotation may not yield higher points over a season, but also shows how the effect of rotations on team success keep increasing as the market value of teams increases. [ABSTRACT FROM AUTHOR]

Performance Analysis (PA) is viewed as an integral feature of soccer; however, the processes underpinning such practice are often described as simple, linear procedures. This fails to acknowledge the dynamism of PA and given increased investment and employment of analysts in professional soccer, scrutiny of the current processes and duties associated with the role would seem timely. To this purpose, eight full-time analysts in the English Football League (EFL) and English National League (National League) participated in in-depth semi-structured interviews and transcripts were subjected to inductive reflective thematic analysis. The data analysis revealed two higher-order categories (Flying solo / Coach control) and four themes classified as lower-order (PA pragmatism / Identifying indicators / The reticent coach / Autocratic presentations). The findings of this study highlight that the responsibilities of the performance analyst range from acting on their own initiative to responding to requests and instructions from the coach. Subsequently, the responsibility for individual actions/activities related to PA is dependent on what aspects of analysis are to be used, who is the recipient of the data/video/presentation, when in the relationship between analyst and coach the activities are developed and when in the match-play process they are carried out. [ABSTRACT FROM AUTHOR]

The relationship between motivational climate and psychological sporting abilities could be influenced by levels of competitive anxiety and self-confidence. The purpose of this research was to explore the relationships between empowering and disempowering motivational climates with negative coping control and attentional control, analyzing whether there was an effect of self-confidence and competitive anxiety on these relationships. A total of 328 male adolescents, aged between 14 and 18 years (M = 15.85; SD = 1.44), participated in this research. To collect the information, the Empowering and Disempowering Motivational Climate Questionnaire (EDMCQ-C), the Inventario Psicológico de Ejecución Deportiva (IPED), and the Revised Competitive State Anxiety Inventory-2 (CSAI-2R) were used. The structural equation model revealed positive and statistically significant associations between empowering motivational climate and self-confidence, between disempowering climate and competitive anxiety, as well as between self-confidence and psychological sporting abilities (negative coping control and attentional control). On the other hand, the analyses highlighted negative relationships between competitive anxiety and negative coping control, as well as attentional control. Furthermore, the model revealed indirect associations between empowering climate and negative coping control, and attentional control through self-confidence, as well as between disempowering climate and negative coping control, and attentional control through competitive anxiety. This information could be valuable for professionals in the field of sports, including coaches, psychologists, athletes, managers, or even individuals close to the athletes such as family members or mentors. [ABSTRACT FROM AUTHOR]

The literature on systematic aspects of goal scoring in football is rich, while little is known about random influences. This study focuses on an unsystematic element of goal scoring, namely rebounds, where a shot that bounces back from another player or the goal creates contested opportunities. Aspects including causes, match situation, player positioning and pitch zones were investigated for 554 rebound goals from seven seasons (2012/2013–2018/2019) of the English Premier League. Rebounds were predominantly caused by short distance and defensive errors, with goalkeepers playing a crucial role. Interestingly, the superiority of home teams and stronger teams to score significantly more goals than away teams and weaker teams can also be observed for rebound goals. Rebound goals are particularly prevalent in zones close to the goal, more prevalent after corners than non-rebound goals and associated with a high number of players in the penalty box. Overall, high similarities exist between rebound and non-rebound goals, while differences in match situations and spatial patterns suggest unique characteristics of rebound goals. These results are in line with the notion of systematicity and randomness concurrently contributing to success in football. More research appears useful to further disentangle the influence of both factors. [ABSTRACT FROM AUTHOR]

The aim of the present study was to analyse the influence of the constraints led approach (CLA) systems, such as the playing space, the number of players and the numerical game situations (superiority, equality and numerical inferiority) on the technical-tactical actions of U-11 players in small-sided games (SSGs). A case study was developed where two of the CLA constraint systems were applied on three SSG where the dimensions of the game space were modified (SSG1: 160 m2 ; SSG2 and SSG3: 155 m2) and the numerical game situation against the opposing team (SSG1: equality; SSG2 and SSG3: superiority/inferiority). The study sample consisted of U-11 players (n = 8) competing at federated level in Spain (10.25 ± 0.45 years; 2.21 ± 0.61 years of experience). The results of this study show an very strong degree of association between the game modalities and the way of obtaining the ball (2Ln(BFp10) = 10.06) and a strong association between the game modalities and the zone of origin of the ball (2 Ln(BFp10) = 6.02). It should be noted that a positive association was found between games modes and ball height in obtaining the ball (2Ln(BFp10) = 4.06); type of conduction (2Ln(BFp10) = 5.88); technical action (2Ln(BFp10)= 2.32) and efficiency (2Ln(BFp10) = 4.04). These data can help coaches to optimize the training process of young players by modifying the training tasks based on the constraint systems proposed in this study. [ABSTRACT FROM AUTHOR]

Currently, most research into the evolution of player performance in women's football has focused on physical performance. In contrast, we lack data-driven research into the technical and tactical developments of the women's game. This paper aims to fill this research gap by analysing an extensive longitudinal dataset containing event data for 3510 matches over eight years in the game's top leagues. It uses analytics techniques to assess changes in technical skills and tactical behaviours in the women's game. Tactically, we observe longer possession sequences and fewer long-distance shots. Technically, we observe that players are completing more difficult and valuable passes at a higher rate, and putting a higher percentage of shots on target, with a particular emphasis on aiming for the corners of the goal. These findings could aid football practitioners to account for the developments of the game. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of manipulating ball possession directionality (i.e., NO direction, MULTI direction or ONE direction) on the physical, tactical and technical performance of youth football players during small-sided games (SSGs). A total of 18 male youth football players (age: 13.6 ± 0.4 years) participated in four testing days, where they completed three random order experimental tasks based on a 4vs4 SSG: (i) NO direction, where players performed a ball possession task without a specific direction to progress; (ii) MULTI direction, where two neutral players were added to the top of each pitch and players could use them to maintain possession; and (iii) ONE direction, where each team defended and scored in two small goals placed at opposite ends of the pitch. In the positioning perspective, the NO condition showed a higher spatial exploration index than the other two conditions (p =.001), while higher distance to the nearest teammate was identified in the MULTI (p =.007) and to the nearest opponent in the ONE (p <.001). In the physical variables, higher game pace (p =.002), total distance covered (p <.001) and jogging distance (p <.001) were identified in the MULTI than the other conditions. Lastly, from the technical perspective, players revealed better passing decision-making (p =.004) in the ONE than NO or MULTI conditions. Based on these results, coaches may use NO condition to emphasize space exploration, MULTI to increase external load and game pace, while ONE to emphasize technical actions related to ball control and pass. [ABSTRACT FROM AUTHOR]

Background: Previous studies have reported that spondylolysis occurs predominantly at the L5 and L4 levels, with defects at higher levels occurring in <5% of cases. However, computed tomography and radiography were the primary imaging modalities in these studies. Current evidence regarding diagnostic imaging for pediatric lumbar spondylolysis suggests that magnetic resonance imaging (MRI) is as accurate as computed tomography in detecting early stress reactions of the pars interarticularis or pedicles without fractures while avoiding radiation exposure. The early detection of spondylolysis results in a higher likelihood of bony union and a decreased likelihood of spondylolisthesis. Hypothesis: The increased use of MRI may reveal a larger proportion of spondylolysis in patients who experience an injury at a higher spinal level than previously reported. Study Design: Cross-sectional study; Level of evidence, 3. Methods: The medical records of 902 pediatric and adolescent athletes (364 female, 538 male) diagnosed with symptomatic pars interarticularis and pedicle stress injuries at 2 academic medical centers between 2016 and 2021 were retrospectively reviewed. All patients had MRI scans taken at the time of diagnosis. Only patients with pars/pedicle edema on MRI were included. Data regarding spondylolysis stage, spinal level of injury, unilateral versus bilateral injury, sport participation, and MRI protocol over the 5-year study period were analyzed. Results: Male patients presented at older ages than female patients (P <.001). Soccer was the most common sport at symptom onset and the second most common single-sport activity among those who specialized (participating in 1 sport year-round at the exclusion of others), behind gymnastics. The mean symptom duration was 4.0 months. Although most patients (83.5%) had exclusively lower lumbar stress injuries, 9.1% of injuries occurred at or above the L3 level. Over half of the patients had active single-level pars/pedicle fractures on MRI, with a mean symptom duration before presentation in this subgroup of 4.0 months. Even when pars/pedicle stress reactions were excluded from analysis, 7.1% of patients were injured at or above the L3 level. Conclusion: Among male and female athletes aged 8 to 21 years presenting with symptomatic pars interarticularis and pedicle stress injuries evaluated by MRI at the time of initial diagnosis, there was a higher incidence of upper lumbar stress injuries than previously reported. [ABSTRACT FROM AUTHOR]

Background: Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes. Purpose: To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR). Study Design: Cohort study; Level of evidence, 3. Methods: A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level. Results: A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P =.019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P =.003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P =.002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups. Conclusion: Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level. [ABSTRACT FROM AUTHOR]

Background: Cam morphology develops during skeletal growth, but its influence on cartilage and the labrum in high-impact athletes later in life is unknown. Purpose: To (1) explore the association between the presence and duration of cam morphology during adolescence and the cartilage and labral status 7 to 12 years later and (2) report the prevalence of cartilage loss and labral damage in a population of young male athletes (<32 years old) who played professional soccer during skeletal growth. Study Design: Cohort study (Prognosis); Level of evidence, 2. Methods: A total of 89 healthy male academy soccer players from the Dutch soccer club Feyenoord (aged 12-19 years) were included at baseline. At baseline and 2.5- and 5-year follow-ups, standardized supine anteroposterior pelvis and frog-leg lateral radiographs of each hip were obtained. At 12-year follow-up, magnetic resonance imaging of both hips was performed. Cam morphology was defined by a validated alpha angle ≥60° on radiographs at baseline or 2.5- or 5-year follow-up when the growth plates were closed. Hips with the presence of cam morphology at baseline or at 2.5-year follow-up were classified as having a "longer duration" of cam morphology. Hips with cam morphology only present since 5-year follow-up were classified as having a "shorter duration" of cam morphology. At 12-year follow-up, cartilage loss and labral abnormalities were assessed semiquantitatively. Associations were estimated using logistic regression, adjusted for age and body mass index. Results: Overall, 35 patients (70 hips) with a mean age of 28.0 ± 2.0 years and mean body mass index of 24.1 ± 1.8 participated at 12-year follow-up. Cam morphology was present in 56 of 70 hips (80%). The prevalence of cartilage loss was 52% in hips with cam morphology and 21% in hips without cam morphology (adjusted odds ratio, 4.52 [95% CI, 1.16-17.61]; P =.03). A labral abnormality was present in 77% of hips with cam morphology and in 64% of hips without cam morphology (adjusted odds ratio, 1.99 [95% CI, 0.59-6.73]; P =.27). The duration of cam morphology did not influence these associations. Conclusion: The development of cam morphology during skeletal growth was associated with future magnetic resonance imaging findings consistent with cartilage loss in young adults but not with labral abnormalities. [ABSTRACT FROM AUTHOR]

Background: Football (soccer) is the world's most popular team sport. Purpose: To comprehensively examine the brain in football (soccer) players, with the use of magnetic resonance imaging (MRI) techniques. Material and Methods: The study involved 65 football players and 62 controls. The MR examinations were performed using MR 1.5-T system (Optima MR 360; GE Medical Systems). The examinations were carried out in the 3D Bravo, CUBE, FSEpropeller, and diffusion-weighted imaging (DWI) sequences. The 1HMRS signal was obtained from the volume of interest in the frontal and occipital lobes on both sides. Results: The present study, based on structural MRI, shows some changes in the brains of the group of football players. The findings show asymmetry of the ventricular system in four football players, arachnoid cysts in the parieto-occipital region, and pineal cysts. NAA/Cr concentration in the right frontal lobe was lower in the football players than in the controls, and the Glx/Cr concentration in the right occipital lobe was higher. The apparent diffusion coefficient value is lower in football players in the occipital lobes. Conclusion: Playing football can cause measurable changes in the brain, known to occur in patients diagnosed with traumatic brain injury. The present findings fill the gap in the literature by contributing evidence showing that playing football may lead to changes in the brain, without clinical symptoms of concussion. [ABSTRACT FROM AUTHOR]

In this study, we examined whether experience level and various dual motor and cognitive or single tasks influenced young soccer players' physical performance during small-sided games. Participants were 72 players from U-13 (n = 36) and U-17 (n = 36) groups who participated in 3-to-a-side small-sided games under four experimental conditions: control, a secondary motor task, an additional related secondary cognitive task, and an additional secondary non-specific task. We used GPS devices to measure physical performance in terms of distances covered and accelerations at different thresholds. We found no significant interaction effect between player experience and task condition (p =.540), meaning that dual tasks had comparable effects on players of different experience levels. There were significant main effects of both experience level (p <.001) and condition (p <.001) on most physically related variables. Older players outperformed younger ones, particularly in high-intensity actions. While secondary motor tasks decreased physical performance, secondary cognitive tasks, irrespective of specificity, did not impair players' performances. In conclusion, experience level did not influence the players' physical response to dual tasks, and a secondary motor task was more disruptive to physical performance than either of two types of secondary cognitive tasks. Cognitive tasks can be incorporated into soccer training without compromising physical performance. [ABSTRACT FROM AUTHOR]

Our aim in the present study was to test the efficacy of a 13-week, 19-session psychological intervention program on young soccer players' competitive anxiety and their sport psychological profiles. Participants were 37 players in the under-15 age category, of which 18 players formed the experimental group (M age = 14.67 years, SD =.48) and 19 players formed the control group (M age = 14.23 years, SD =.42); this was a quasi-experimental design without random assignment to groups. We had all participants complete the Psychological Inventory of Sport Performance (IPED), the Questionnaire of Psychological Characteristics of Sport Performance (CPRD), and the Competition State Anxiety Inventory-2 (CSAI-2) before and after the intervention. Results indicated positive effects for the intervention group (but not the control group) on stress control and motivation dimensions of the CPRD, cognitive anxiety and self-confidence on the CSAI-2, and self-confidence and attentional control on the IPED. These results suggest that psychological training for athletes contributes to their improved psychological skills, providing them tools to better adapt to the competitive environment. [ABSTRACT FROM AUTHOR]

A reliable, versatile means of assessing visuo-motor reaction time (V-MRT) is important to football (soccer) players for many reasons, including the fact that faster V-MRT is a critical sport skill that may even play a role in reducing common sports injuries to the lower muscle extremities that can be associated with lost time on the field. We aimed to determine the test-retest reliability and minimum detectable change (MDC) of the Brain Pro System for assessing lower-extremity V-MRT in young male football players. We had 68 participants (M age = 16.35, SD = 1.71 years) perform two assessment sessions one-week apart. For test-retest reliability, we calculated a one-way intra-class correlation coefficient (ICC) at the 95% confidence interval and provided the standard error of measurement (SEM) and minimum detectable change (MDC) (MDC = SEM × 1.96 × √2) for V-MRTs. We obtained excellent V-MRT test-retest reliability for dominant lower-extremity, non-dominant lower-extremity, and dominant and non-dominant lower-extremities (ICC2,1 =.93, 95%CI =.89–.96; ICC2,1 =.94, 95%CI =.91–.96; ICC2,1 =.96, 95%CI =.94–.97; respectively). The calculated MDC for the dominant lower-extremity V-MRT, the non-dominant lower-extremity V-MRT, and dominant and non-dominant lower-extremities (random) V-MRT were 1.21 seconds, 1.13 seconds, and 1.21 seconds, respectively. Brain Pro System had excellent reliability for assessing lower-extremity V-MRT in young male football players. The MDC values at the 95% confidence level (MDC95) we obtained were reliable for assessing clinically meaningful V-MRT changes. [ABSTRACT FROM AUTHOR]

Background: Soccer boots are produced with different stud patterns and configurations to provide players with extra traction on specific surface types to minimize slipping and improve player performance. Excessive traction, however, can lead to foot fixation injuries, particularly anterior cruciate ligament tears. Purpose/Hypothesis: The purpose of this study was to explore the translational traction properties of 5 different outsole configurations moving in 4 different directions across both natural grass and artificial grass (AG) playing surfaces. It was hypothesized that longer studs or studs with an asymmetric shape would yield a higher traction coefficient compared with the recommended stud configuration for the given playing surface. Study Design: Descriptive laboratory study. Methods: A custom-built testing apparatus recorded the translational traction of 5 different soccer boots moving in an anterior, posterior, medial, or lateral direction on both natural grass and AG playing surfaces. A 3-way analysis of variance was performed to determine the effect of outsole configuration on the traction, and a post hoc Tukey analysis was performed to compare different outsole configurations with a control. Results: For the natural grass playing surface, the longer and asymmetric studs yielded a significantly higher (P <.05) traction coefficient on 75% of loading scenarios, while on AG, they yielded a significantly higher traction on 50% of loading scenarios. Conclusion: Some soccer boots yielded higher traction values compared with the recommended configuration. Clinical Relevance: The results highlight the importance of boot selection on different playing surfaces. Higher traction values could increase the injury risk for players due to excessive traction and foot fixation. [ABSTRACT FROM AUTHOR]

This research aims to evaluate the effectiveness of corner kicks, analyze the goal patterns resulting from corner kicks, and develop a model for the implementation of optimal corner kick strategies. The study used a descriptive retrospective design, and the data consisted of 455.898 corner kicks from matches played by 768 teams in 33 different leagues and an international tournament (UEFA). Six different models based on logistic regression were developed and analyzed. The results showed that more goals were scored from certain zones (1c, 2b, and 2c) inside the penalty area than from others (p < 0.001). According to logistic regression, zones 1c and 2c increased the probability of scoring a goal by 1.12 and 1.08 times, respectively, compared to other regions. In addition, it is noticeable that the probability of scoring from the zones varies considerably depending on the type of kick. Further results showed that there were no statistically significant differences between goals scored from in-swing and out-swing corners, but significant differences were found for the other types of corners. Finally, 3.1% of all corners resulted in goals, and 69% of those goals resulted in a draw or the team taking the lead in the match. For these reasons, it is important to develop new corner-kick strategies in order to score goals and win matches. [ABSTRACT FROM AUTHOR]

As a variation of small-sided games (SSGs), Thomas Tuchel's hexagonal shaped possession drills attracted a lot of attention in coaches' soccer education. Changing certain variables (e.g. pitch size) is one traditional approach to provide an optimal stimulus for a specific training goal. Therefore, the presented field study investigated whether hexagonal shaped drills show changes in tactical key performance indicators (KPIs) using positional data in a controlled experimental setting. Data were collected using player tracking systems (1 Hz) in 5 versus 5 SSGs in both the full-size pitch and pitch with cut-off corners condition. At match-related level, trial duration and outcome were examined. At player-related level, the tactical KPIs effective playing space (EPS), length-per-width ratio, space control and overplayed defenders were analyzed. The results show significant differences in length-per-width ratio (attacking team), the EPS and space control (30m-zone). However, it could not be confirmed that hexagonal shaped drills are played more vertically and faster toward the goal than on a normal pitch, as there were no changes in trial duration, outcome or overplayed defenders. Nevertheless, an experimental positional data analysis paradigm is a useful approach to investigate tactical principles in high-level professional soccer. [ABSTRACT FROM AUTHOR]

While it is evident that disparities exist across various areas on a football pitch, and numerous studies have investigated spatio-temporal datasets in football for various analyses, there remains a lack of an effective method for quantitatively partitioning the pitch into specific areas with different properties. To address this gap, this article presents a novel approach to partitioning a football pitch into distinct areas based on successful passing paths that lead to goals. Utilizing hierarchical clustering and spatial/temporal features derived from successful passing paths, the study provides multi-level partitions of the football pitch, revealing detailed insights into the relationships between specific areas and scored shots in football games. Empirical analysis of over 4000 successful passing paths from various football leagues and international football events demonstrates the effectiveness of the proposed methodology in identifying and understanding the diverse areas of football pitches. The findings suggest practical applications in football analysis, aiding coaches and specialists in tactics development and informing player positioning and movement strategies. [ABSTRACT FROM AUTHOR]

Background: A range of innovative performance analysis metrics have been applied in recent years to investigate aspects of football using tempo-spatial and network analyses. These approaches have gained traction within some professional teams to quantify and assess features of collective behaviour. However, metrics employed are rarely created from, or clearly link to, domain expertise and as a result coaches may be hesitant of their value. Therefore, the aim of this study was to identify coach perceptions of spatial temporal and network metrics and identify the feasibility of an iterative and collaborative process to developing metrics. Methods: Two rounds of semi-structured interviews were conducted with three Scottish youth international UEFA Pro License coaches (age: 47.0 ± 2.7 years) with a focus on aligning metrics with concepts and principles of play. An iterative approach was used centring around spatial-temporal and network metrics and their adaptation. Reflexive thematic analyses were conducted with final metrics categorized as resonant (accurately describing concept or principles of play), relevant (appropriate but with limitations that need improvement), or hesitant (skeptical of usefulness). Results: Across the ten recognized principles of play, nine metrics were identified and adapted to varying degrees. Resonant metrics included: network intensity (mobility), distance between defenders (discipline), triangles (support), team length and distance between deepest defender and goal line (depth). Conclusion: Coaches recognize principles of play within complex collective behaviour metrics and should be encouraged to collaborate with analysts to develop support systems that may prove to be more valuable and usable. [ABSTRACT FROM AUTHOR]

This study investigated the perceptions of players and football club staff regarding de-selection from the youth international football environment. Prior research into youth football de-selection focuses on players' experiences of being released from their club environment; however, research is yet to understand the effect of de-selection from international football. The authors completed semi-structured interviews with 11 current youth international footballers and nine members of leadership staff from English Premier League youth academies, including academy directors, technical directors and heads of coaching. It was found that players had a strong identity as an international footballer and that once de-selected, it could be difficult to adapt to a change in status within their group at the club. The club staff also suggested that clubs do little to support the player once de-selected as although they perceive the player as being part of their development programme, they viewed international football as an area that was not their responsibility. Practical applications are discussed, including the need for clear justifications of de-selection and 'after-care' solutions. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the positional dynamics in soccer small-sided games (SSGs) with either greater length (SSGlength) or width (SSGwidth) with official games. Twenty four Brazilian U-20 national-level players participated in six SSGs training sessions with two different SSG configurations: SSGlength (4v4, 40 m length and 26 m width) and SSGwidth (4v4, 26 m length and 40 m width). Positional dynamics variables were monitored and compared to official games. Linear mixed regression model was fitted using the situations as fixed effect, and, when appropriate, player and/or group as random effects. When compared to SSGlength and SSGwidth, official games showed a greater Relative Team Length, LPWratio, Spacial Exploration Index (SEI), and Strech Index, with a large or very large effect size. The SSGlength elicited higher values of Relative Team Width, LPWratio, and SEI when compared to SSGwidth. No significant differences were found between SSGlength and SSGwidth for Relative Team Length (small effect size), and SI (small effect size). Both group and player as random effects showed low variances. We concluded that the tactical behaviours during the 4v4 SSG differed substantially from the competitive tactical behaviour during the official games. In addition, changing the orientation of the playing field did not make the positional dynamics of the SSGs more similar to the official games. [ABSTRACT FROM AUTHOR]

Despite interest in multi-sports training as a strategy to enhance long-term player development in soccer, current practice within English professional soccer academies is not well understood. This study explored the use of multi-sports training by English professional soccer academies (i.e., if multi-sports training was used, how often, session duration, activity type and age-group variations), and practitioners' perspectives with respect to player development (i.e., perceived physical/sociological benefits of; and barriers to use) using an online survey. One practitioner per club, per age category (i.e., Foundation (<9 to <12 years), Youth (<13 to <16 years) and Professional (<18 to <23 years)) was permitted to respond. Sixty practitioners responded, of which, 48% worked with U18-U23 players; 42% with U13–14 and U15–16 players, respectively; 20% with U9–10 players and 33% with U11–12 players. Half (n = 30) of the respondents used multi-sports training for a total of 1 (IQR 1–2) session and 30 (13 to 60) minutes per week. Respondents 'agreed' or 'strongly agreed' that multi-sports training improved physical outcomes, reduced injury risk, helped to avoid early professionalism, and improved communication and problem-solving. Several barriers to inclusion were identified, such as limited training time, lack of equipment and attrition from other staff and players. In summary, although multi-sports training was used by only ∼50% of practitioners, indicating that many clubs specialise in deliberate soccer practice, most practitioners perceived multi-sports training to be beneficial to player development. [ABSTRACT FROM AUTHOR]

The objective of this study is to build a mathematical model that predicts the success of a goal kick in soccer. The model is based on an ensemble of neural networks whose inputs are five features extracted directly from the goal kick and one more that depends on the opposing team. This new variable is calculated using a hierarchical cluster analysis and divides the possible opponents by their defensive strategy. It is shown that it has a relevant importance in the result of a goal kick, which validates the idea of using the presented methodology that takes into account the opponent's tactics when analyzing specific plays of a soccer match. [ABSTRACT FROM AUTHOR]

Background: Return to sport (RTS) after treatment of an anterior cruciate ligament (ACL) tear is a critical parameter to assess the outcome of a surgical procedure. However, few studies have investigated RTS after ACL repair. Purpose: To evaluate RTS of a group of amateur soccer players at a minimum follow-up of 2 years after ACL repair. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review of all patients treated with acute ACL repair was conducted. A total of 50 amateur soccer players were included in the study. Patients were examined clinically or contacted to complete postoperative patient-reported outcome measures, namely the Knee injury and Osteoarthritis Outcome Score, the International Knee Documentation Committee questionnaire, the ACL–Return to Sport After Injury scale, and the Forgotten Joint Score–12. Results: The patients' mean age was 25.8 ± 7.7 years (range, 14-47 years), and the mean follow-up was 34.3 ± 10.7 months (range, 24-51.3 months). The median Tegner Activity Scale score was 9. The ACL repair failure rate was 16% (8/50). The mean time from repair to failure was 23.1 ± 12.7 months (range, 6-44 months), and the mean age of patients who sustained ACL repair failure was 19.9 ± 3.3 years (range, 14-24 years), significantly lower compared with patients who did not experience ACL repair failure (26.9 ± 7.9 years; range, 16-47 years; P =.017). Multivariate analysis showed that age ≤21 years was the only significant risk factor for ACL repair failure (odds ratio, 5.45; confidence interval, 1.24-27.91; P =.041). Excluding the 8 patients who experienced repair failure, 31 of 42 patients (73.8%) returned to soccer after ACL repair, with 29 of the 31 (93.5%) returning at their preinjury level of play. Moreover, patients who played competitive soccer and returned to their preinjury level of play were significantly younger than those who did not return to their preinjury level of play (mean, 21.1 ± 3.4 vs 29.2 ± 9.5 years, respectively; P =.002) and had significantly better ACL-Return to Sport After Injury scores (mean, 96.6 ± 4 vs 87.8 ± 11, respectively; P =.044). Conclusion: In this study, 73.8% (n = 31) of patients returned to playing soccer, of whom 93.5% (n = 29) returned to their preinjury level after ACL repair. The failure rate was 16% (n = 8) and mainly involved patients ≤21 years old. [ABSTRACT FROM AUTHOR]

Knowing where the body is in space requires reference to a stored model of the size and shape of body parts, termed the body model. This study sought to investigate the characteristics of the implicit body model of the trunk by assessing the position sense of midline and lateral body landmarks. Sixty-nine healthy participants localised midline and lateral body landmarks on their thorax, waist and hips, with perceived positions of these landmarks compared to actual positions. This study demonstrates evidence of a significant distortion of the implicit body model of the trunk, presenting as a squatter trunk, wider at the waist and hips. A significant difference was found between perceived and actual location in the horizontal (x) and vertical (y) directions for the majority of trunk landmarks. Evidence of a rightward bias was noted in the perception of six of the nine body landmarks in the horizontal (x) direction, including all midline levels. In the vertical (y) direction, a substantial inferior bias was evident at the thorax and waist. The implicit body model of the trunk is shown to be distorted, with the lumbar spine (waist-to-hip region) held to be shorter and wider than reality. [ABSTRACT FROM AUTHOR]

Dynamic visual acuity (DVA) is considered an essential component for studying the visual function, especially in challenging environments like team sports. Beyond frequent comparative studies, much information is still lacking about the mechanisms underlying DVA and possible differences in stimulus presentation. It is crucial to understand the performance of DVA under different conditions of contrast and trajectories to achieve more specific data and better ecological validity of measurements. Fifty-five top professional male Spanish athletes, including 23 soccer, 14 basketball, and 18 water polo players were selected. Static visual acuity (SVA) was evaluated at 5 m. DVA was determined at 2 m under combined conditions of velocity (52°/s), three trajectories (horizontal, diagonal 45° and 135°) and two contrasts (99.7% and 13%). Significant differences in most DVA conditions measurements show that the best scores correspond to horizontal, over diagonal trajectories, and high contrast. The correlation between SVA and DVA showed a different relationship depending on the contrast conditions. Professional soccer, basketball, and water polo players have similar characteristics with reference to all the DVA evaluated conditions. [ABSTRACT FROM AUTHOR]

Background: The understanding of noncontact anterior cruciate ligament (ACL) injury causation in soccer has improved over the past decades. Bidimensional video analyses have significantly augmented our awareness, representing to date the only practical method to describe injury biomechanics. However, the extent of the problem continues to raise serious concerns. Purpose: To advance our understanding of the causal pathways leading to ACL injury with a large-scale reconstruction of 3-dimensional (3D) whole-body joint kinematics of injuries that occurred to male elite soccer players, as well as to compare the joint angle time course among situational patterns. Study Design: Descriptive laboratory study. Methods: A total of 33 consecutive noncontact and indirect contact ACL injuries that occurred in 6 national and 2 international professional leagues (seasons 2020-2021 to 2022-2023 until December 2022) were analyzed: (1) multiview noncoaxial television images were inspected; (2) multiple camera views were taken from 400 ms before the initial ground contact to 200 ms after the injury frame; (3) a size-matched pitch was modeled and used to calibrate cameras; (4) a 3D skeletal model was adjusted to fit the player's pose in each frame/view; and (5) poses were interpolated, and Euler joint angles were extracted. Results: The authors reconstructed the 3D lower limb joint kinematic curves preceding and during ACL injuries in 33 cases; notably, a sudden external (up to 5°) and then internal knee rotation was observed after the initial contact and before the injury frame. The overall kinematics at injury were knee moderately flexed (45.9°± 21.7°), abducted (4.3°± 5.1°), and externally rotated (3.0°± 6.4°); trunk shallowly flexed (17.4°± 12.5°) and rotated and tilted toward the injured side; and hip flexed (32.0°± 18.7°), abducted (31.1°± 12.0°), and slightly internally rotated (6.6°± 12.2°). Variable behaviors were observed at the ankle level. Conclusion: Via reconstruction of the sequence of whole-body joint motion leading to injury, we confirmed the accepted gross biomechanics (dynamic valgus trend). This study significantly enriches the current knowledge on multiplanar kinematic features (transverse and coronal plane rotations). Furthermore, it was shown that ACL injuries in male professional soccer players manifest through distinct biomechanical footprints related to the concurrent game situation. Clinical Relevance: Interventions aimed at reducing ACL injuries in soccer should consider that environmental features (ie, situational patterns) affect injury mechanics. [ABSTRACT FROM AUTHOR]

In this study we, evaluated the effects of a 10-week sensorimotor exercise program on the thickness and side-to-side asymmetry of the lateral abdominal muscles in adolescent soccer players. From among 120 initially recruited participants, we included 90 athletes (aged 10–17 years old) in our final analysis. Healthy athletes who met our inclusion criteria were randomly divided into comparative experimental and control groups. Sensorimotor exercises were conducted twice weekly for 10-weeks in the experimental group, and the control group received no intervention. We took ultrasound measurements when participants were in supine and standing rest positions. In the supine position, the experimental group (a) reduced the asymmetry of the internal oblique (IO) muscle by 0.4 mm (MD: 0.7; 95% CI 0.6–1.1); (b) increased the thickness of the external oblique (EO) muscle on the right by 0.7 mm (MD: 0.2; 95% CI 0.1–0.6) and on the left by 0.9 mm (MD: 0.2, 95% CI 0.2–0.7); and (c) increased the muscle on the IO right by 0.8 mm (MD: 0.3; 95% CI 0.2–0.9) and on the, left by 1.2 mm (MD: 0.4 95% CI 0.3–1.1). In a standing position the experimental group increased the thickness of the EO on the right by 1.5 mm (MD: 0.6; 95% CI 0.03–1.2) and on the left by 2.1 mm (MD: 0.6; 95% CI 0.1–1.3) and increased the IO on the right by 1.2 mm (MD: 0.7; 95% CI 0.2–1.7) and on the left by 1.1 mm (MD: 0.9; 95%CI 0.1–2.0). Thus, this 10-week program of additional sensorimotor exercises reduced the (side-to-side) asymmetry of the internal oblique muscle and increased the thickness of the EO and IO muscles in young football players. [ABSTRACT FROM AUTHOR]

As the sport industry witnesses a surge in the type and volume of data-driven decisions, the general question of the process of information development remains: how is data used to develop meaningful information? And does the presence of novel quantitative data sources lend greater objectivity to match analysis? Study 1 examines how 12 football analysts use the same qualitative (video) and quantitative (event and position) data to develop information constituting a typical opponent report for an upcoming match, while Study 2 investigates the agreement between grade evaluations of these opponent reports by numerous professional coaches. Findings of Study 1 through independent-samples t -tests (t (18) = 3.922, p = 0.001) indicate a clear dominance of qualitative video data over quantitative event and position data in all opponent reports. Despite the presence of quantitative data sources, analysts tend to prefer annotated video data. Possible relations to previous experience and familiarity with data, coach–analyst preferences and biases are discussed. Results from Study 2 show extremely weak intra-class correlations (ICC) (r = 0.147; p = 0.011) between different grades awarded to the same video, depicting a clear lack of agreement in what coaches consider a good opponent report. Furthermore, coaches most valued the comprehensibility and relevance of the report. No significant associations were found between use of either data type and better grades. The subjectivity of the coaching process highlighting preferences regarding data validity and negotiations of adopting new key performance indicators (KPIs) is discussed, alongside limitations of the sample as well as the level of coach–analysts involved. [ABSTRACT FROM AUTHOR]

This paper considers how player acceleration changes in soccer relative to age. A plot of average maximum acceleration versus age is produced. The construction of the plot is based on methods from functional data analysis and the availability of tracking data from the 2019 season of the Chinese Super League. For an individual player, we calculate his maximum acceleration for each single match of the 2019 season. Since the players' maximum accelerations are observed only on a single season instead of their entire careers, we treat them as incomplete functional data, called functional snippets. The average maximum acceleration, i.e., the mean function of the functional snippets rather than full curves is estimated by a local linear smoothing method. The most important observation is that the shape of the acceleration curve closely resembles curves of soccer performance versus age. This observation has implications for predicting future performance since acceleration is more easily and more accurately measured than performance. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine how coaching behaviors, coaching experience, and coach training relate to physical activity (PA) levels of children during their participation in a youth sport program. Youth soccer teams (N = 27) serving children ages 6–11 years were directly observed during one practice using momentary time-sampling procedures consisting of 30-s intervals (10-s observation, 20-s recording). Team coaches reported prior coaching experience, training, and demographic characteristics. Multilevel logistic regression was conducted to describe associations between coaching behaviors and intensity of children's PA. Interaction terms were added to the models to determine if the associations differed across girls-only, boys-only, and coed teams. ANOVAs were used to describe associations between coaching experience, coach training, and team PA level. Children were more likely to engage in moderate or vigorous PA when coaches were watching without verbal feedback (Odds Ratio [OR], 3.2, 95% CI = 1.70–5.83) or watching with verbal feedback (OR, 2.1, 95% CI = 1.27–3.59), compared to when the coach was disengaged, regardless of team sex composition. The number of prior seasons coached was positively related to team PA levels. These findings can be used to inform coaching strategies for promoting increased PA during youth sport practices. [ABSTRACT FROM AUTHOR]

This study determined the contributors to soccer technical skills in grassroots youth soccer players using a machine learning approach. One hundred and sixty-two boys aged 7 to 14 (mean ± SD = 10.5 ± 2.1) years, who were regularly engaged in grassroots soccer undertook assessments of anthropometry and maturity offset (the time from age at peak height velocity (APHV)), fundamental movement skills (FMS), perceived physical competence, and physical fitness and technical soccer skill using the University of Ghent dribbling test. Coaches rated player's overall soccer skills for their age. Statistical analysis was undertaken, using machine learning models to predict technical skills from the other variables. A stepwise recursive feature elimination with a 5-fold cross-validation method was used to eliminate the worst-performing features and both L1 and L2 regularisation were evaluated during the process. Five models (linear, ridge, lasso, random forest, and boosted trees) were then used in a heuristic approach using a small subset of suitable algorithms to achieve a reasonable level of accuracy within a reasonable time frame to make predictions and compare them to a test set to understand the predictive capabilities of the models. Results from the machine learning analysis indicated that the total FMS score (0 to 50) was the most important feature in predicting technical soccer skills followed by coach rating of child skills for their age, years of playing experience and APHV. Using a random forest, technical skills could be predicted with 99% accuracy in boys who play grassroots soccer, with FMS being the most important contributor. [ABSTRACT FROM AUTHOR]

The benefits of an external focus in motor learning have been well-established in adults, but findings in studies with children have been far more variable. Recent research also suggests that a holistic focus of attention may also enhance motor learning relative to an internal focus, but few studies have tested this strategy with children. Therefore, this study aimed to determine the effect of an internal (IF), external (EF), holistic focus (HF) and no focus control condition on the learning of a soccer shooting task in male children. Male participants (N = 60) between the ages of 9 and 11 completed 60 acquisition trials shooting at a low target at a distance of 7 m while focusing on an assigned cue. After 48 h, participants returned for a 10-trial retention test and a 10-trial transfer test shooting from a distance of 8 m. Results showed that the EF group was more accurate than control throughout acquisition (p =.027). In retention, all focus groups were more accurate than control (p 's <.001), and an EF trended toward being more accurate than in IF (p =.059). In transfer, all focus groups were more accurate than control (p 's <.001), and EF was more accurate than HF (p =.009). To our surprise, a clear benefit of an EF and HF relative to an IF was not observed. Future work should consider whether this may be due to the nature of the cues selected, or if there are other constraints that may influence when children do or do not benefit from an EF and HF. [ABSTRACT FROM AUTHOR]