Science & medicine in football最新文献

Isometric knee-flexor testing is commonplace in soccer, yet data to inform choice of knee-flexion angle are limited. This study aimed to compare peak force production and muscle activation between two isometric knee-flexor tests. To compare peak force, 43 male soccer players (age 21.5 ± 5 years; stature 180.3 ± 6.3 cm; body mass 74.6 ± 8.9 kg) completed 3 × 5-second maximal efforts on the Nordbord device (Vald Performance) with a 0- (ISO-Prone) and 30-degree (ISO-30) knee angle, respectively. To compare peak muscle activation, a further 13 trained male participants (25 ± 6 years; 178.2 ± 5.6 cm; 79.6 ± 13.2 kg) completed 3 × 5-second maximal efforts with wireless surface electromyography electrodes placed on the Gluteus Maximus, Adductor Magnus, Semitendinosus, Biceps Femoris (long and short heads) and Medial Gastrocnemius. Paired samples t-tests were used to detect differences in force output between tests and Pearson's correlations to quantify associations. A Yuen's modified t-test estimated the trimmed mean differences in muscle activation between tests. Higher peak forces were observed in the ISO-30, with mean differences of 56.4N (36.8 to 75.9 [95% CI]) and 52.9N (33.7 to 72.3 [95% CI]) for right (367 vs 314N) and left legs (351 vs 294N), respectively. Moderate correlations were observed in peak force for left (r = 0.55 (0.29 to 0.73 [95%CI])) and right (r = 0.64 (0.42 to 0.79 [95%CI]) legs. No differences in muscle activation were observed. Peak force varies between the ISO-Prone and ISO-30, with moderate associations between tests, indicating that the tests should not be used interchangeably.

This exploratory video analysis study aimed to review characteristics of potential head injury situations during a men's professional international football tournament. For 64 matches of the FIFA World Cup Qatar 2022™ FIFA analysts used match footage to record all potential head injury situations. A potential head injury situation was defined as a player staying down for more than 5 s and/or requesting medical attention, and where the body impact location included the player's head. Characteristics were further recorded for match, player (i.e. player action including aerial duels), medical assessment, and outcome (e.g. substitution). Descriptive statistics are reported as well as Pearson's Chi-squared test (or Fisher's exact test) to explore potential head injury situations more likely to result in medical attention. In total, 149 potential head injury situations occurred in 56 matches (mean 2.33/match, range 0-6) involving 117 players. Eight matches resulted in no incidents. Aerial duels were the most frequent match characteristic leading to a potential head injury situation. Injury stoppage with on-pitch medical assessment occurred in 35 of the 149 potential head injury situations (23%), with pitch-side assessment also occurring in 15 situations (10%), resulting in four concussion substitutions. Players were more likely to require medical attention for potential head injuries sustained when the ball was loose (χ² = 6.88; p = 0.038) when the injured player was jumping (FET p = 0.044) and for head-to-head contact (FET p = <0.001). Further exploration of aerial duels during match play which do and do not lead to potential and actual head injuries is recommended.

Despite the rise of data generation in football, the expertise of data analytics within the sport is relatively underdeveloped. To further understand the landscape, a cross-sectional, observational study design was used to survey practitioners in senior, professional, or semi-professional football. Areas of interest included the personnel involved (the 'who'), the data collected (the 'what'), and the analytical techniques employed (the 'how'). A total of 206 practitioners completed an online survey, with representation from all six FIFA confederations. Of the 206 respondents, 86% were male, 13% female, and 1% preferred not to disclose their gender. Respondents were categorised as working in either the performance (73%), data (18%), or medical (9%) department. Heterogeneity was observed in responses across all departments regarding training load metrics, outcome metrics, methodological attributes, and measurement properties. Evidence sources used prior to implementing a new metric varied between departments, with performance (63%) and medical (67%) staff relying on professional industry and/or community, while data staff (57%) utilised more in-house projects. The analytical approach used most frequently was exploratory data analysis (90%), with modelling, forecasting, and predicting the least frequent (54%). Respondents reported using a mix of solutions for data storage, aggregating and analysing, and reporting and visualising data. Spreadsheets were cited as a popular solution for data wrangling and reporting tasks. The findings provide an overview of current data ecosystems and information systems in modern football organisations. These results can be used to improve data analytics service provision in football by helping identify areas for development and progression.

The studded outsole of a soccer boot provides additional traction to players to minimise the risk of slipping while performing high-speed manoeuvres. As excessive traction can lead to foot fixation and injury risk, there has been significant research surrounding the influence of stud configuration on the level of traction generated. This previous research, however, has predominately focused on the stud patterns, foot morphology and lower limb loading patterns of male players. As the popularity of women's soccer increases, the aim of this investigation was to examine the differences in translational traction of female-specific soccer boots and male soccer boots currently available. A custom-built apparatus was used to determine the translational traction on both natural and artificial grass for four different movement directions. It was hypothesised that the female-specific boot in each pair would produce lower levels of translational traction as they are designed to be safer for female players who are more at risk of lower limb fixation injuries compared to males. An independent samples T-test showed that while there were some loading conditions where female boots produced lower translational traction compared to male boots, across all loading scenarios there was no significant difference between male and female boots (p = 0.818), thus the null hypothesis was rejected.

Speed zone thresholds in women's soccer are often based on thresholds derived from the men's game. This study applied a data-mining approach to generate (a) team-based speed zone thresholds, and (b) individualised speed zone thresholds for elite female soccer players. Activity data from 47 elite club-level female soccer players was collected using multi-constellation global navigation satellite systems technology during 76 competitive matches between 2020 and 2021. The elbow method was used to identify the number of thresholds in the dataset, and spectral clustering was applied to each player's instantaneous match-play speed data to determine the value of these thresholds. Team-based categories were then formed by calculating the mean value of each threshold from the individual players. Three speed zone thresholds were identified (1.12, 2.83, and 5.10 m·s^-1). The newly-generated speed zone thresholds resulted in greater distance covered in the top three speed zones (all p < 0.05) compared to existing speed zone thresholds for women's and men's soccer. The between-player coefficient of variation for individualised speed zone thresholds was 13.0% for the lowest threshold, 12.9% for the middle threshold, and 8.5% for the highest threshold. Average maximum match-play running speed was a significant predictor of all individualised speed zone thresholds (lowest threshold: β = 0.13, p = 0.016; middle threshold: β = 0.44, p = 0.001; highest threshold: β = 0.74, p < 0.001). This study demonstrates a data-mining approach to establish team-based and individualised speed zone thresholds for women's soccer that could be applied within practical and academic settings.

This study aimed to assess the agreement between daily self-reported and actigraphy-derived sleep duration in high-level male youth soccer players over a 35-day period. Secondary analyses examined the agreement between daily self-reported sleep duration and objective time in bed (TIB), as well as the agreement between sleep questionnaire responses and averaged actigraphy data. Forty-eight players wore actigraphy devices nightly and completed daily sleep diaries for 35 consecutive days. After the monitoring period, players completed the Pittsburgh Sleep Quality Index (PSQI). Agreement was assessed using Bland - Altman analysis. Results showed a mean bias of - 60 min between self-reported and objective sleep duration, with wide limits of agreement (-02:09 to +00:15 h), indicating poor agreement. Similar results were observed when comparing self-reported sleep to objective TIB. PSQI responses overestimated average sleep duration for the same time period by 69 min (LoA: -17 to +154 min). Overall, self-reported sleep duration consistently overestimated sleep duration and failed to meet the predefined threshold for acceptable agreement of 30 min. These findings suggest that daily self-report and questionnaire-based sleep estimates may not be reliable proxies for objective sleep data in youth soccer athletes. While subjective methods may still hold practical utility for routine screening, objective tools should be prioritized for sleep monitoring.

Aim: Our study aimed to investigate the relationship between playing time and well-being in Danish under-17 elite level football players.

Methods: Throughout the 2021/22 competitive playing season, the World Health Organization-5 index (WHO-5) was administered bi-weekly to assess well-being. Playing time was separately collected from an official database.

Statistics: A cross-lagged panel model with a multi-level set-up was applied.

Results: Average response rate was 67 ± 14% (mean±SD) with a significant variation observed throughout the investigation period. Average prevalence of well-being levels below the WHO-5 cut-off values for depression and anxiety (≤13 points, with ≤7 indicating severe symptoms) was 10 ± 12%. At least once during the season, 55.4% of all players had well-being levels indicating potential mental health concerns. Also, temporal patterns in well-being were observed, with more players having levels closer to the cut-off value during pre-season than towards the end of the season. Cross-lagged effects were found between measures of playing time and well-being on the day after a match (MD + 1). This indicates a relationship between match involvement and psychological well-being.

Summary and practical implications: Playing time seems to be associated with well-being in male youth elite football players. Frequent well-being monitoring and thoughtful playing time management in youth academy football may provide individualized player support throughout the playing season and proactively safeguard mental health.

The aim of this study was to explore female football (soccer) players' perspectives of heading the ball, and perceived header injury risk. A qualitative approach was undertaken using reflexive thematic analysis. Focus groups and individual interviews were conducted using a semi-structured interview guide. Participants also completed a survey containing a validated concussion knowledge and attitudes questionnaire. Participants were recruited throughout New Zealand and focus groups/interviews were completed via Zoom. Otter.ai was used to assist in transcription and NVivo was used for coding and initial theme development. Nineteen female football players were included across six focus groups and three individual interviews. Three main themes were generated. Firstly, the battle of 'risk versus reward' explored players' views around the importance of heading for the game and perceived injury risks. Secondly, spare the brain versus train the skill described players' avoidance of heading the ball rather than training the skill due to potential injury risk and/or concern around performing repeated headers. Finally, changes in perspectives following concussion and appetite for managing injury risk explored how players perceived the experience of a concussion to have influenced their headers, factors influencing their concussion attitudes and potential return to heading guidelines and injury prevention tools. Female footballers reported actively avoiding repetitive header training due to their perceived injury risk and experiencing symptoms. While female players value the importance of headers for the game of football, there is also some concern around the safety and potential injury risk, especially in those with a history of concussion.

Female athletes have long been under-represented in sports medicine research, and data on the association of surgical procedures on elite athletic careers remain limited. This study estimated career longevity and satisfaction among elite retired women football players. Data were collected via an anonymous online survey from a previously published cohort of 560 retired elite female football athletes, who provided information on playing history, surgical history, and assessments of long-term joint function, physical activity, and general health. Linear and ordinal regression analyses were used to evaluate factors associated with career longevity, career satisfaction, and post-career satisfaction. Higher competition level was associated with longer career duration (β = 2.57, p < 0.001), while more years since retirement was linked to shorter careers (β = -0.23, p = 0.018). Playing as a defender (OR: 1.71, p = 0.035), more years since retirement (OR: 1.03, p = 0.016), and better mental (OR: 1.05, p < 0.001) and physical health (OR: 1.04, p = 0.034) were associated with greater career satisfaction. Post-career satisfaction was higher with more years since retirement (OR: 1.05, p < 0.001) and better mental health (OR: 1.14, p < 0.001), while anterior cruciate ligament (ACL) reconstruction during the career was linked to lower post-career satisfaction (OR: 0.50, p = 0.034). Retired elite women football players with more years since retirement and better mental health reported greater career and post-career satisfaction. Those with a history of ACL reconstruction reported lower post-career satisfaction, potentially due to ongoing health issues.