As previous literature updates, I have performed a PubCrawler search looking for football articles in NCBI Medline (PubMed) and GenBank databases.

Following studies were retrieved for this week:

1 Seasonal Comparison of Pre-Adolescent Soccer Players‘ Physical Performance Using an Objective Physical Test Battery

Reference: J Funct Morphol Kinesiol. 2024 Sep 17;9(3):166. doi: 10.3390/jfmk9030166.
Authors: Giacomo Villa, Foivos Papaioannou, Manuela Galli, Veronica Cimolin
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11417703/pdf/jfmk-09-00166.pdf
Summary: Soccer is a multifactorial sport, requiring physical, psychological, technical, and tactical skills to succeed. Monitoring and comparing physical characteristics over time is essential to assess players‘ development, customize training, and prevent injury. The use of wearable sensors is essential to provide accurate and objective physical data. In this longitudinal study, 128 male adolescent soccer players (from Under 12 to Under 19) were evaluated at two time points (pre- and post-season). Participants completed the Euleria Lab test battery, including stability, countermovement and consecutive jumps, agility, and quick feet tests. A single Inertial Measurement Unit sensor provided quantitative data on fifteen performance metrics. Percentage changes were compared to the Smallest Worthwhile Changes to assess significant changes over time. The results showed significant improvements in most variables, including a 19.7% increase in quick feet, 10.9% in stability, and 9.6% in countermovement jumps. In principal component analysis, we identified four principal components-strength-power, balance, speed-agility, and stiffness-that explained over 80% of the variance. These findings align with previous studies assessing seasonal changes in adolescent soccer players, showing that the proposed test battery seems to be adequate to highlight physical performance changes and provide coaches with meaningful data to customize training and reduce injury rates.

2 Ecological-Dynamic Approach vs. Traditional Prescriptive Approach in Improving Technical Skills of Young Soccer Players

Reference: J Funct Morphol Kinesiol. 2024 Sep 14;9(3):162. doi: 10.3390/jfmk9030162.
Authors: Giovanni Esposito, Rosario Ceruso, Sara Aliberti, Gaetano Raiola
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11417948/pdf/jfmk-09-00162.pdf
Summary: This study contributes to expanding the existing literature on learning technical skills in youth soccer by comparing the effectiveness of different training approaches in the development of passing skills. The ecological-dynamic approach, which emphasizes the continuous and adaptive interaction between the athlete and the environment, is analyzed in comparison to the traditional prescriptive approach, which relies on predefined techniques and exercises. The aim of the study is to determine which of the two approaches is more effective in improving the performance of young soccer players. Methods: Thirty players (age 12 ± 1.2 years) were randomly assigned to two groups: the ecological-dynamic group (ECG) and a control group (CON). Both groups underwent an eight-week training program with equal sessions. The ECG group’s training focused on adjusting constraints like the learning environment, game rules, and visual restrictions to boost adaptability and problem-solving skills. The CON group followed a traditional prescriptive approach with specific instructions, goal setting, immediate feedback, and structured exercise progression. Passing abilities were evaluated before and after the program using the Loughborough Soccer Passing Test, with a retention test administered five weeks later. Descriptive statistics, including mean values and percentage improvements, were used. A repeated measures ANOVA compared differences between the groups. Results: The analysis revealed a significant Occasion × Group interaction for all performance variables, indicating that the ECG group experienced greater improvements than the CON group. Specifically, the ECG group showed significant reductions in Trial Time (p = 0.001, ηp2 = 0.6), Penalty Time (p = 0.016, ηp2 = 0.4), and Overall Performance (p = 0.011, ηp2 = 0.8) from pre-test to post-test. However, these improvements did not persist into the retention test (p = 0.131, p = 0.792, and p = 0.192, respectively). The CON group also improved significantly in Trial Time (p = 0.003), Penalty Time (p = 0.002), and Overall Performance (p = 0.001) from pre-test to post-test, but with smaller effect sizes and no sustained gains at retention. Conclusions: The ecological-dynamic approach (EDG) has proven to be more effective in enhancing passing skills compared to the traditional prescriptive approach (CON). Although both methods led to performance improvements, the EDG group achieved more significant progress.

3 Self-Regulated Learning Assessment in Young Soccer Players: Beyond Competitive Levels

Reference: J Strength Cond Res. 2024 Sep 20. doi: 10.1519/JSC.0000000000004950. Online ahead of print.
Authors: Athos Trecroci, Luca Cavaggioni, Alessio Rossi, Tindaro Bongiovanni, Pietro Luigi Invernizzi, Damiano Formenti, Stefano Longo
Summary: This study explores self-regulated learning (SRL) among young soccer players, transcending the traditional focus on competitive levels. One hundred twenty-four soccer players of regional and provincial levels from under 14 to under 17 age groups voluntarily participated in the study and were combined into a single group. A median-split method based on total time performance was used to separate players into low performers (LPs) and high performers (HPs) from a 90° change of direction dribbling test. The self-regulation of learning-self-report scale for sport practice (SRL-SRS-SP) with a 5-factor solution (planning, reflection, effort, self-efficacy, and self-supervision) and 31 items was used. The score was based on a 1-5 Likert scale. The level of significance was set at p-value < 0.05. The SRL-SRS-SP total score by HP players differed significantly from that of LP players (p = 0.015). Regarding each subscale, HP players showed significantly higher scores than LP players (p = 0.011) for planning, whereas no differences were observed for the remaining factors (p ≥ 0.05). The main observation of this study revealed that HP soccer players had a greater level of engagement in the learning process with a remarkable ability to plan for specific improvement than LP peers. This suggests that the competitive level might not be the sole determinant of differences in SRL. Therefore, strength and conditioning coaches should emphasize metacognitive and motivational components because of their crucial role in enhancing technical and physical performance.

4 Footwear technology, running outputs, and technical performance in soccer match-play

Reference: J Appl Physiol (1985). 2024 Oct 1;137(4):831-832. doi: 10.1152/japplphysiol.00580.2024.
Authors: Luiz Henrique Palucci Vieira, Paulo Roberto Pereira Santiago, Rodrigo Aquino
Download link: https://journals.physiology.org/doi/epdf/10.1152/japplphysiol.00580.2024

5 Anthropometric and physical fitness characteristics of male South African youth soccer players

Reference: J Sports Med Phys Fitness. 2024 Sep 25. doi: 10.23736/S0022-4707.24.16246-9. Online ahead of print.
Authors: Prescott Mahlangu, Alliance Kubayi, Abel Toriola, Andries Monyeki, Darren Kwong, Andrew Green
Summary: This study comparatively investigates the anthropometric and physical fitness characteristics of male South African players by age group, competitive level and playing position. The sample consisted of 201 youth soccer players drawn from six sports academies in South Africa. Players were subjected to standardized protocols for anthropometric measurements (stature, body mass and body fat percentage) and physical fitness tests (flexibility, vertical jump, push-ups, sit-ups, muscle strength, agility, 30-m sprint and V̇O2max). A series of two-way analyses of variance was performed to determine the interactions between playing position (goalkeeper, defender, midfielder or attacker) or age group (13, under-15, under-17 or under-19) and competitive level (elite or non-elite). The results show significant interaction effects of agility, body fat percentage and sprint speed between the players‘ competitive levels and age group (P<0.05). No interaction effect was found between playing position and competitive level in any anthropometric or physical fitness variable (P>0.05). However, playing position exhibited significant main effects in the youth players‘ aerobic endurance and body mass (P<0.05). The results provide practical implications for tailoring position-specific conditioning regimes that optimize effective soccer performance.

6 Intrinsic Risk Factors for Noncontact Anterior Cruciate Ligament Injury in Young Female Soccer Players: A Prospective Cohort Study

Reference: Am J Sports Med. 2024 Sep 25:3635465241278745. doi: 10.1177/03635465241278745. Online ahead of print.
Authors: Shuji Taketomi, Kohei Kawaguchi, Yuri Mizutani, Seira Takei, Ryota Yamagami, Kenichi Kono, Ryo Murakami, Takahiro Arakawa et al.
Summary: Previous studies have attempted to determine prognostic factors for predicting the occurrence of noncontact anterior cruciate ligament (ACL) injuries. However, studies on risk factors for noncontact ACL injuries in Asian female soccer players are limited. The aim was to identify intrinsic risk factors for noncontact ACL injuries among young female Asian soccer players. This study evaluated 145 female Japanese soccer players for potential risk factors for noncontact ACL injury during the preseason medical assessment. In total, 25 variables were examined-including anthropometric data, joint range of motion, muscle flexibility, muscle strength, and balance measurements. Participants were monitored throughout a single season for noncontact ACL injuries diagnosed by physicians. Noncontact ACL injuries occurred in 13 knees of 13 players (9%). Lower hamstring-to-quadriceps ratio (0.44 ± 0.07 vs 0.50 ± 0.10; P = .04), greater knee extension muscle strength (3.2 ± 0.5 vs 2.7 ± 0.5 N·m/kg; P < .01), and longer playing experience (10.8 ± 3 vs 8.1 ± 4.2 years; P = .02) were significantly associated with new-onset noncontact ACL injuries in young female soccer players. No statistically significant between-group differences were found for any other variables. New-onset noncontact ACL injury in young female soccer players was significantly associated with lower hamstring-to-quadriceps ratio, greater knee extension muscle strength, and longer soccer experience. These findings will help develop strategies for preventing noncontact ACL injuries among female soccer players.

7 Isometric Midthigh-Pull Testing: Reliability and Correlation With Key Functional Capacities in Young Soccer Players

Reference: Int J Sports Physiol Perform. 2024 Sep 24:1-9. doi: 10.1123/ijspp.2024-0203. Online ahead of print.
Authors: Vincenzo Rago, Fábio Yuzo Nakamura, Carlos Suarez-Balsera, Javier Arnaiz-Lastras, Pedro Figueiredo
Summary: We examined the reliability of force parameters derived from the isometric midthigh pull (IMTP) and their correlation with the functional capacities of young soccer players. Data were collected from 20 young professional soccer players within and between 2 sessions (after 1 wk) using a 1000-Hz force plate. Performance outputs in all IMTP parameters were consistent and showed moderate to excellent reliability (intraclass correlation coefficient = .72-1.00) within and between sessions. However, all parameters reported a marginal ability to detect chronic changes in performance (smallest worthwhile change [SWC] < standard error of measurement [SEM]) except for peak vertical force (PF) parameters, which showed good usefulness (SWC > SEM). Absolute PF was correlated with the countermovement-jump (CMJ) total impulse (CMJ-TI; r = .54), whereas relative PF (to body mass) was correlated with CMJ height, CMJ peak power, and the last speed of the 30:15 Intermittent Fitness Test (VIFT; r = .40 to .63). IMTP time-dependent forces were correlated with CMJ-TI (r = .52 to .62). The IMTP impulse parameters were positively correlated with CMJ-TI (r = .48 to .58) and negatively with VIFT (r = -.44 to -.38). None of the IMTP parameters were correlated either with the CMJ mean propulsive force or with any linear acceleration times. All IMTP parameters can be adopted by practitioners involved with testing young soccer players based on their acceptable reliability criteria. However, caution should be taken when interpreting the time-dependent variables based on their marginal usefulness when assessing performance. Generally, a greater PF was associated with a greater vertical power based on its correlation to CMJ.

8 Sensitivity of Minimally Invasive Protocols to Monitor Changes in Endurance Performance in Elite Junior Football (Soccer) Players

Reference: Int J Sports Physiol Perform. 2024 Sep 24:1-8. doi: 10.1123/ijspp.2024-0199. Online ahead of print.
Authors: Jan Schimpchen, Paulo F Correia, Tim Meyer
Summary: Adequate physical fitness is a key requirement for elite footballers. Maximal fitness tests are the standard for evaluating fitness but are often fatiguing and time consuming. This study investigated the ability of various minimally invasive protocols to reflect changes in standard parameters of football players‘ physical fitness. Twenty-one elite junior footballers performed 2 standard fitness tests (stepwise incremental treadmill test with blood-lactate and heart-rate [HR] measurements and Yo-Yo Intermittent Recovery 1 test) and various proxy fitness evaluations (submaximal runs with measurement of exercise HR and HR recovery and external-to-internal load ratios with data collected during match play) 3 times over the course of 19 weeks. Changes in the standard parameters were compared with changes in proxy parameters. Changes in maximal endurance performance showed small to moderate associations with HR-based proxy parameters (r = -.1 to -.46; P = .004-.56), whereas changes in the running velocity at anaerobic threshold had trivial to moderate associations (r = -.07 to -.39; P = .01-.67). Alterations in HR recovery following 2 short, submaximal runs were very largely correlated with changes in the running velocity corresponding to an HR of 170 beats·min-1 (r = -.74 and r = -.75; P < .001). Changes in external-to-internal load ratios derived from match play were not significantly correlated with changes in any of the standard parameters (r = -.03 to .31; P > .05). Parameters of maximal running performance and parameters describing physiological thresholds do not seem to be adequately captured by different minimally invasive protocols. In contrast, HR recovery following short, submaximal runs may be a valid tool to monitor changes in aerobic endurance adaptations.

9 „We are on the outside but it’s okay“: A grounded theory of cooperation between parents, coaches, and administrators in professional youth soccer academies

Reference: Psychol Sport Exerc. 2024 Sep 24:102746. doi: 10.1016/j.psychsport.2024.102746. Online ahead of print.
Authors: Valeria C Eckardt, Travis E Dorsch
Summary: Parents need to cooperate with professional organizations to support their children’s development and health. In sports, knowledge on how parents, coaches, and organizations can successfully coordinate their behavior and work together for a common cause is lacking. This study was designed to identify a grounded theory of cooperation as a social process between parents and organizational stakeholders in youth soccer academies. Intensive interviews were conducted with parents (n = 9), coaches (n = 11), and administrators (n = 14) across 14 youth soccer academies in Germany. Data were analyzed using initial coding, focused coding, and theoretical integration following constructivist grounded theory methodology. The grounded theory produced comprises several processes aimed at building, maintaining, and reinforcing effective cooperation between parents, coaches, and administrators. Acknowledging parents as part of the academy, providing a thorough onboarding, and defining parental roles are essential for cooperation to evolve. Cooperation was viewed as a responsive, dynamic, and iterative process impacted by person and context factors. Findings are interpreted through a systems lens highlighting nuanced dependencies between cognitive, emotional, and behavioral patterns. The grounded theory provides implications for future research targeting the intersection of persons and contexts in youth sport. For practitioners, we propose an evidence-based program on developing cooperation.

10 Exploring the association of mindfulness, confidence, competitive state anxiety, and attention control in soccer penalty shootouts

Reference: Front Psychol. 2024 Sep 12:15:1439654. doi: 10.3389/fpsyg.2024.1439654. eCollection 2024.
Authors: Lisi Shi, Longjun Jing, Huilin Wang, Yang Liu
Summary: Penalty shootouts are a pivotal factor influencing outcomes in soccer matches. Soccer players face the challenge of overcoming physical fatigue and psychological pressure when taking penalty kicks. Instances of low confidence and competitive state anxiety during matches exacerbate the detrimental impact on attention control, particularly in non-target defined features, leading to suboptimal performance during penalty kicks. This cross-sectional survey investigates the relationship between mindfulness and attention control. Convenient sampling was employed to gather a sample of 266 soccer players from sports teams and training bases in Central and South China who had participated in city-level or higher-level competitions. A structural equation model, created using AMOS 26, was employed for hypotheses validation. Findings reveal a positive correlation between mindfulness and confidence, and a negative correlation between mindfulness and competitive state anxiety. Additionally, confidence positively associates with attention control, while competitive state anxiety shows a negative relationship with attention control. Confidence and competitive state anxiety also function as mediators in the correlation between mindfulness and attention control. To elaborate, soccer penalty kickers with heightened mindfulness demonstrate increased confidence levels, reduced competitive state anxiety, and improved attention control. Mindfulness training positively influences attention control during penalty kicks for soccer players. To boost players‘ confidence, alleviate competitive state anxiety, and enhance their performance during penalty shootouts, it is recommended that governments increase investment in mindfulness training and talent development. Coaches should enhance their understanding of mindfulness training mechanisms, and athletes themselves should prioritize mindfulness training.

11 The Impact of Heat Exposure on the Health and Performance of Soccer Players: A Narrative Review and Bibliometric Analysis

Reference: Sports (Basel). 2024 Sep 10;12(9):249. doi: 10.3390/sports12090249.
Authors: Spyridon Plakias, Themistoklis Tsatalas, Minas A Mina, Christos Kokkotis, Andreas D Flouris, Giannis Giakas
Download link: https://www.mdpi.com/2075-4663/12/9/249
Summary: The impact of heat exposure on the health and performance of soccer players is a widely discussed topic. The purpose of this study is to provide a comprehensive overview of the international literature that has addressed this issue. To achieve this objective, we initially conducted a bibliometric analysis and a literature review of the main topics that emerged through bibliometric techniques. For the bibliometric analysis, we employed VOSviewer software (version 1.6.20.0) and used documents found in the Scopus database. The analysis ultimately included 133 documents published in 66 sources. Key journals and authors were identified, highlighting significant contributions to the field. Science mapping revealed collaboration networks and research focus areas such as physical health, safety, soccer performance, dehydration and hydration, physiological mechanisms and monitoring, nutrition, fluid intake, and cooling techniques. Based on the key areas highlighted in the identified clusters, which emerged from the co-occurrence analysis of the author keywords, the following three topics were developed in the literature review: (a) the physiology and health of football players; (b) performance impacts; and (c) strategies to prevent negative consequences. The review showed that high heat exposure can reduce the physical and cognitive performance of athletes and prove detrimental to their health. To mitigate the negative consequences, appropriate hydration strategies, heat acclimatization, and cooling techniques have been proposed. Our findings provide the international scientific community with comprehensive knowledge of the existing literature, laying the foundation for future research while simultaneously offering coaches and athletes the necessary theoretical knowledge to help improve safety and performance.

12 Association of VDR Polymorphisms with Muscle Mass Development in Elite Young Soccer Players: A Pilot Study

Reference: Sports (Basel). 2024 Sep 13;12(9):253. doi: 10.3390/sports12090253.
Authors: Laura Flore, Renato Robledo, Laura Dettori, Marco Scorcu, Paolo Francalacci, Filippo Tocco, Myosotis Massidda, Carla Maria Calò
Download link: https://www.mdpi.com/2075-4663/12/9/253
Summary: The vitamin D receptor (VDR) is an important candidate gene in musculoskeletal phenotypes. Polymorphisms in the VDR have been previously associated with several pathologies and muscular strength in athletes and elderly people; however, the literature reported contradictory results. The object of this research was to verify the association between the most studied VDR variants (rs2228570, rs7975232, and rs1544410) and the increase in muscle mass in elite young soccer players. A sample of 55 soccer players (15-18 years old) from a professional team were selected for this study. DNA was extracted by the salting-out method, and polymorphisms were genotyped by PCR-RFLP, followed by 2% agarose gel electrophoresis. To test the effect of the three SNPs (single nucleotide polymorphisms), a logistic regression analysis was applied. The body composition determination was carried out through the skinfold thickness method, and the muscular area of the arm and lower limb were calculated using the Frisancho formula. All three polymorphisms met the Hardy-Weinberg equilibrium (p > 0.05) and their frequencies fell within the worldwide variability. A significant correlation between rs1544410 and the increase in calf muscle mass was observed. Individuals carrying the A allele showed higher calf muscular mass than those carrying the G allele (p = 0.034). Moreover, a haplotype analysis applied to the two SNPs in linkage disequilibrium (rs7975232 and rs1544410) showed that the AG haplotype appeared negatively correlated to the calf muscle area. In conclusion, we confirm an association between VDR polymorphisms and muscular mass that could encourage the genetic screening of the VDR gene to identify a potential risk of injury and for individual nutritional interventions.

13 Variation in Accelerometer-Derived Instantaneous Acceleration Distribution Curves of Elite Male Soccer Players According to Playing Position: A Pilot Study

Reference: Sports (Basel). 2024 Sep 23;12(9):263. doi: 10.3390/sports12090263.
Authors: Pedro Oliveira, Felipe Arruda Moura, Ivan Baptista, Fábio Yuzo Nakamura, José Afonso
Download link: https://www.mdpi.com/2075-4663/12/9/263
Summary: The incorporation of triaxial accelerometers into Global Positioning Systems (GPS) has significantly advanced our understanding of accelerations in sports. However, inter-positional differences are unknown. This study aimed to explore the variability of acceleration and deceleration (Acc) distribution curves according to players‘ positions during soccer matches. Thirty-seven male players from a national-level Portuguese club were monitored using 10 Hz GPS with an embedded accelerometer during the 2021/2022 season. Resultant Acc was obtained from the x (lateral), y (frontal/back), and z (vertical) axes and expressed in gravitational units (g). Statistical Parametric Mapping was employed to compare playing positions: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM), and strikers (ST). All positions exhibited a decreasing Acc distribution curve, very similar in shape, with a high frequency of events in the lower ranges (i.e., 0 to 1 g) and a lower frequency of events in the higher values (2 to 10 g). Post hoc comparisons revealed significant differences between all positions, except between FB and WM. Out of 1000 points in the curve, CD had 540, 535, 414, and 264 different points compared to FB, CM, WM, and ST, respectively. These findings indicate that players in different positions face distinct demands during matches, emphasizing the need for position-specific Acc analysis and training programming. By analyzing Acc as a continuous variable, this study highlights the importance of individualized monitoring to ensure the comprehensive and precise tracking of all player activities, without overlooking or omitting critical information.

14 A new injury prevention program ‚FUNBALL‘ improves cognitive performance of young football (soccer) players: A cluster randomized controlled trial

Reference: Psychol Sport Exerc. 2024 Sep 19:76:102743. doi: 10.1016/j.psychsport.2024.102743. Online ahead of print.
Authors: Rina Meha, Rilind Obërtinca, Karen Aus der Fünten, Kai Leisge, Sabine Schaefer
Summary: The youth football injury prevention program ‚FUNBALL‘ contains exercises requiring high cognitive demands, which are performed concurrently to the training of the respective motor task. This study evaluates whether the program increases cognitive performances of young football players. 1253 football players (aged 13-19 years old) were randomly assigned to either a control (CON) or an intervention (INT) group. The INT group performed the ‚FUNBALL‘ program at least twice per week in their training sessions for one season (9 months). The CON group continued their training routine. From the total sample, the cognitive performance of 304 players (n = 135 CON; n = 169 INT) was assessed at the beginning and the end of the season using the Cogstate® Brief Battery, with the following subtests: One Back test (accuracy), Two Back test (accuracy), One Card Learning test (accuracy), Chase Test (correct moves per second), Set Shifting (accuracy), Identification test (speed), Detection test (speed), Groton Maze Learning Test (accuracy), and Groton Maze Learning Test Delayed Recall (accuracy). A multivariate analysis of variance (MANOVA) on the cognitive performance improvements from pre-to posttest showed that the INT group improved their performances more strongly than the CON group for all cognitive tests, namely for working memory, visual learning, visual motor control, attention, psychomotor function, memory, and executive function. The present study indicates that the exercise-based injury prevention program ‚FUNBALL‘ may improve the cognitive performance of young football players. Future research should include an active control group, and should investigate whether the improvement in cognition also has beneficial effects on in-game performance.

14 A Narrative Review of Soccer-Related Concussion Management in Children and Adults Over the Past 10 Years

Reference: Cureus. 2024 Aug 22;16(8):e67510. doi: 10.7759/cureus.67510. eCollection 2024 Aug.
Authors: Pamela Castillo Rocha, Maria D Beletanga, Osvaldo Pangrazio, Francisco Forriol, Christopher Howards, Mildred C Franco-Liñan, Gabriela Restrepo-Rodas et al.
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11416142/pdf/cureus-0016-00000067510.pdf
Summary: Soccer-related concussions (SRC) have increased despite an overall reduction of concussions across all sports activities. Few papers have studied the mechanism of injury, and have been mostly done in high-income countries or focused on small populations, preventing generalization. Our goal was to analyze the available data published about SRC over the past 10 years, independent of the country’s income level. A narrative review was performed. The definition of sport-related concussion from the American Academy of Neurology and studies published between 2013 and 2023 were used. Of 1210 articles, 45 met the inclusion criteria. The results showed that SRC was more frequent in females (57.6%) than males (44.3%). Player-to-player interaction was the most common mechanism of injury, with midfielders being the most affected position. The first providers to diagnose were certified athletic trainers, within the first 24 hours. Neurological evaluations, including SCAT (Sport Assessment Concussion Tool) and ImPact (Immediate Post-concussion Assessment and Cognitive Testing), were included in 42.2% of the studies, with SCAT and ImPact specifically used in 15.5% and 11% of cases, respectively. Need for hospitalization was found in 8.9% of participants and one player required surgical intervention. At the time of the concussion, confusion, dizziness, and amnesia were reported frequently. However, after the concussion, headaches and dizziness were prevalent. Follow-up data were included in 35.5% of the studies. On average, children missed 15 practice days and returned to school after 8 days. In conclusion, future research should focus on the circumstances around head-to-head injuries by age, sex, and level of professionalism as well as the importance of early diagnosis and careful follow-up, to protect the players and improve their outcomes.

15 How Match-Related Variables Influence the Physical Demands of Professional Female Soccer Players during the Regular Season

Reference: J Funct Morphol Kinesiol. 2024 Aug 28;9(3):149. doi: 10.3390/jfmk9030149.
Authors: Lorenzo Marcelli, Fioretta Silvestri, Gianluca Di Pinto, Maria Chiara Gallotta, Davide Curzi
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11417782/pdf/jfmk-09-00149.pdf
Summary: The purpose was to investigate how contextual or environmental factors may influence the athletic performance of female soccer players during competitions, this study aimed to assess the impact of match-related variables (playing surface; opponent levels; opponent result trends; match status, and match outcomes) on the athletic performance of professional female soccer athletes. Seventeen athletes (25.5 ± 4.3 years of age) from the same team competing in the Italian second division were divided into two groups according to their roles and athletic characteristics: Group A (central defenders and forwards) and Group B (right/left full-backs and midfielders). Total distance (TD) and sprint distance (SD); high-speed running (HSR), acceleration (ACC), and deceleration numbers (DEC); average and maximal heart rate (HR_avg; HR_max); and match-related factors were collected during the 22 regular season matches. A T-test and ANOVA were used to calculate the differences between groups in GPS and HR variables and the effects of match-related factors, respectively. Results showed higher running performance in the B group compared to the A group during matches. Increased ACC number was seen in matches played on artificial turf; winning was associated with decreased HR_max and increased DEC number. Athletes covered higher TD reaching lower HR_max when playing against lower-ranking opponents while matches lost/drawn resulted in higher HSR. High HRs (max and avg) were found when playing against a team with a positive performance trend. In summary, match-related factors and opponents‘ characteristics can affect athletic performance in female soccer athletes. These factors should be considered during in-seasonal training to personalize match preparation and optimize athlete performance.

16 Return to professional football after ICD implantation in athlete with apical hypertrophic cardiomyopathy

Reference: BMJ Case Rep. 2024 Sep 25;17(9):e261255. doi: 10.1136/bcr-2024-261255.
Authors: Amanda Lahti, Erik Ljungström, David Mörtsell, Harald Jorstad
Download link: https://casereports.bmj.com/content/bmjcr/17/9/e261255.full.pdf
Summary: The risk of sports participation in elite athletes with cardiac disease with an indication for implantable cardioverter-defibrillator (ICD) therapy is largely unknown. Currently, international guidelines provide restrictive sports advice for such athletes. This case report presents a professional football player who after an episode of syncope and diagnosis of apical hypertrophic cardiomyopathy expressed a strong wish to explore the feasibility of returning to elite-level sports. After a shared decision-making and monitored stepwise graduated rehabilitation, the athlete made a full return to professional football. Our case indicates that individualised sports advice in elite athletes with cardiac disease and an ICD may be warranted.

17 Male football players have better patient-reported outcomes after primary anterior cruciate ligament reconstruction compared with females

Reference: BMC Sports Sci Med Rehabil. 2024 Sep 25;16(1):199. doi: 10.1186/s13102-024-00996-1.
Authors: Anne Fältström, Martin Hägglund, Joanna Kvist
Download link: https://bmcsportsscimedrehabil.biomedcentral.com/counter/pdf/10.1186/s13102-024-00996-1.pdf
Summary: Sex differences in patient-reported outcomes (PROs) are not well investigated after anterior cruciate ligament (ACL) reconstruction in football players. The aim was to study sex differences in player-related factors, ACL injury characteristics and PROs after primary ACL reconstruction in football players. In this cross-sectional cohort study a survey was sent to 390 male and 403 female football players who were injured when playing football and had undergone a primary ACL reconstruction in the previous 1-3 years. Player-related factors, ACL injury characteristics, and PROs covering knee function, satisfaction with activity level and knee function, and readiness to return to sport were compared between male and females. The questionnaires International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC-SKF), Knee injury and Osteoarthritis Outcome Score (KOOS), ACL-Quality of Life (ACL-QoL) and ACL-Return to Sport after Injury (ACL-RSI) were used. Ninety males (23%) and 283 (70%) females answered the survey, 65 males and 198 females fulfilled the inclusion criteria. Males had returned to football to a higher degree (77% vs 59%, p = 0.008) at any time after ACL reconstruction, but at the time of the survey, an equal number of males and females played football (55% vs 47%, p = 0.239) and had similar activity level according to the Tegner Activity Score (median, 9; interquartile range [IQR], 7, vs median, 8; IQR, 7; p = 0.740). Males were more satisfied with their knee function and activity level and rated higher scores in the IKDC-SKF (mean ± standard deviation, 83 ± 16 vs 76 ± 16, p = 0.006), KOOS Sport/Recreation (79 ± 19 vs 72 ± 22, p = 0.034), KOOS Quality of Life (73 ± 22 vs 64 ± 20, p = 0.008), ACL-QoL (7.6 ± 2 vs 6.8 ± 1.8, p = 0.008), and ACL-RSI (6.7 ± 2.1 vs 5.5 ± 2.3, p < 0.001) than females (all with small – medium effect sizes). Male football players reported more favourable results than females in patient-reported knee function, satisfaction with activity level and knee function, knee-related quality of life and psychological readiness to return to sport 1-3 years after ACL reconstruction. The results contribute to a better understanding of the eventual effect of patient sex on outcomes after ACL reconstruction in football players. However, the clinical importance of these differences is unclear.

18 Nutritional habits of professional team sport athletes: An insight into the carbohydrate, fluid, and caffeine habits of English Premier League football players during match play

Reference: J Sports Sci. 2024 Sep 25:1-8. doi: 10.1080/02640414.2024.2402137. Online ahead of print.
Authors: Andreas M Kasper, James Allan, Daniel Hodges, Paul Catterson, Liam Mason, John Fitzpatrick, Nick Grantham et al.
Summary: The aim was to better understand the in-match fuelling practices of elite football players and compare against current guidelines, we quantified the carbohydrate, fluid, and caffeine intake of players from an English Premier League club (n = 22) during 90 min of competitive match-play. Mean carbohydrate intake across match-play was 17 ± 11 g.h-1 with players demonstrating a preference towards CHO-containing fluids (58%) when compared with semi-solids (38%) and solids (14%), respectively. CHO intake was significantly lower than reported by players (17 ± 11 vs 24.8 ± 11 g.h-1, p < 0.001) during initial consultation. Fluid was ingested at a rate of 0.45 ± 0.14 L.h-1, with 54, 40 and 6% of ingested fluid coming from water, carbohydrate, and electrolyte-only solutions, respectively. The majority of players (91%) met the UEFA guidelines for fluid consumption. Of the players who consumed caffeine across match-play (55%) the average dose was 233 ± 148 mg (2.8 ± 1.1 mg.kg-1 body mass [BM]), which meets the UEFA consensus guidelines for caffeine intake. Caffeine capsules (42%) and caffeine containing fluids (30%) were the preferred format prior to the warm-up whilst caffeine gum was exclusively used prior to kick-off and during the half-time period (100%). We conclude that 81% of the total playing squad failed to meet the current UEFA CHO intake recommendations of 30-60 g.h-1, which may be attributed to the preference towards fluid-based CHOs as the chosen format of delivery.

19 Case Report: Effect of providing penalty kicking tendencies on goalkeeper’s motor behaviour and performance: a case study with an on-field intervention on youth football

Reference: Front Sports Act Living. 2024 Sep 12:6:1356340. doi: 10.3389/fspor.2024.1356340. eCollection 2024.
Authors: Vicente Luis-Del Campo, Pedro Tiago Esteves, Leonardo Palma Monteiro, Filipe Luis Martins Casanova
Download link: https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2024.1356340/full
Summary: The penalty kick is a crucial action in a football match that may determine the final outcome. It features a direct interaction between the shooter and goalkeeper where both search for relevant information as a means to achieve their respective performance goals. A case study, composed of an on-field intervention, was designed to analyze the influence of providing in advance penalty kicking tendencies of the shooters on a youth goalkeeping movement onset and saving performance. Data collection took place over 8 training sessions where a U10 young low-skilled, male goalkeeper and shooters were subjected to a penalty-kick shootout task. In each session, the goalkeeper faced a set of 10 penalty kicks recorded by a high-speed HD camera which allowed to calculate the moment that the shooter hit the ball and the goalkeeper movement onset in the direction of ball trajectory. Results showed that the goalkeeper delayed response initiation in the retention phase, when compared to the baseline and training phases, by moving closer to the foot-to-ball contact time by the penalty shooter. From this study, it can be highlighted that goalkeeping saving actions were adapted to the provision of a priori information about shooter kicking tendencies, to sustain a higher performance of the young goalkeeper during the penalty duelling.

20 Comparison of Inter-Rater and Intra-Rater Reliability of Raters with Different Levels of Experience When Using Landing Error Scoring System (LESS) in Field-Based Screening of Professional Football Players

Reference: Sports (Basel). 2024 Sep 3;12(9):242. doi: 10.3390/sports12090242.
Authors: Nikolaos I Liveris, Charis Tsarbou, Sofia A Xergia, Angelos Papadopoulos, Elias Tsepis
Download link: https://www.mdpi.com/2075-4663/12/9/242
Summary: It is essential for physical sports therapists to use reliable field-based tests to identify potential injury risk factors in athletes. The purpose of this study was to compare the inter- and intra-rater reliability of experienced and novice raters during use of the Landing Error Scoring System (LESS) in a field-based examination of professional football athletes. Thirty-seven male football athletes underwent pre-season LESS assessment. Two raters independently evaluated the recorded landing techniques at two separate intervals, two months apart, following the LESS standard protocol. Inter-and intra-rater values were calculated for the LESS total scores and individual scoring items. The overall LESS scores had excellent intra-rater reliability values for both the experienced (interclass correlation coefficient (ICC) = 0.95, 95% CI, 0.89-0.97; p < 0.001) and novice rater (ICC = 0.95, 95% CI, 0.90-0.97; p < 0.001), and very good to excellent inter-rater values for the first (ICC = 0.90, 95% CI, 0.77-0.95; p < 0.001) and second (ICC = 0.86, 95% CI, 0.71-0.93; p < 0.001) evaluation. Most of the individual scoring items ranged from moderate to perfect agreement. In conclusion, sports physical therapists, regardless of experience, can reliably use the LESS’s total score, through video analysis of the regime. Individual scoring items can inform clinicians about impairments in the landing mechanism but data should be interpreted cautiously

21 Increased anterior pelvic tilt angle elevates the risk of hamstring injuries in soccer player

Reference: Res Sports Med. 2024 Nov 21:1-17. doi: 10.1080/15438627.2024.2430662. Online ahead of print.
Authors: Ahmet Bayrak, Süleyman Patlar
Summary: This study aims to determine the impact of increased anterior pelvic tilt angle on hamstring muscle injuries in football players. An independent t-test was performed to compare right and left anterior pelvic tilt angles. The study was conducted by monitoring 76 different players from a professional club in the Premier Division of Professional Football League over a period of five years. During this time, the hamstring injuries sustained by the players and their severity were recorded using MRI imaging techniques. The comparison of the right and left anterior pelvic tilt angles among players was analysed using an independent t-test for independent groups. The Receiver Operating Characteristic (ROC) analysis was used to determine the threshold value that categorizes the right and left angles. According to the results, a significant impact of the variation in right-left anterior pelvic tilt angle on hamstring muscle injuries was observed (p < 0.05). However, no significant effects were found for the Q angle, tibial torsion, or knee posture (p > 0.05). In conclusion, it can be stated that an increase in the anterior pelvic tilt angle is associated with a higher frequency of hamstring injuries.

22 The Association Between Isometric Shoulder Strength and Sports Performances in University Soccer Players: A Cross-Sectional Study

Reference: Cureus. 2024 Oct 21;16(10):e72041. doi: 10.7759/cureus.72041. eCollection 2024 Oct.
Authors: Ali I Khan, Sumbul Ansari, Zahid Khan, Shahid Raza
Download link: https://www.cureus.com/articles/308515#!/
Summary: Background Soccer, a globally popular sport, demands a complex interplay between physical attributes, including speed, agility, power, and endurance. Although lower-body strength and power are often emphasized, the role of upper-body strength, particularly shoulder strength, remains less explored. Given the importance of upper-body movements in activities such as heading, shooting, and defending, understanding the relationship between shoulder strength and soccer performance is crucial. Aims This study aimed to explore any possible correlation between isometric shoulder muscle strength (flexors and extensors) and sports performance (sprint and agility) and to evaluate whether isometric shoulder strength is associated with sports performance in university-level soccer players. Methods A total of 35 male amateur soccer players were recruited, who underwent demographic measurements such as age, height, weight, and body mass index (BMI), and were then subjected to isometric strength assessment of the shoulder flexors and extensors using a handheld dynamometer (HHD). Subsequently, the players‘ sprint and agility performances were recorded. Appropriate statistical tests were performed on the obtained data. Results The findings revealed a significant negative correlation between shoulder flexor strength and sprinting (r=-0.707, p<0.01) and between shoulder extensor strength and sprinting (r=-0.611, p<0.01). There was no significant correlation between shoulder flexor strength and agility (r=-0.121, p=0.48) or between shoulder extensor strength and agility (r=-0.212, p=0.22). Multiple linear regression analysis revealed that only shoulder flexor strength (β=-0.688, t=-2.651, p=0.01) was found to have statistically significant relationships with sprint performance, explaining 50% of the variance in sprint performance. Conclusions The present study found a negative bidirectional relationship between shoulder muscle strength and sprint performance. Shoulder flexor strength explained 50% of the variance in sprinting performance. This information is useful for physiotherapists, coaches, and trainers to focus on strengthening the shoulder musculature to improve performance.

23 Musculoskeletal Soreness Location and Intensity in Soccer Athletes Across Multiple Seasons

Reference: Clin J Sport Med. 2024 Nov 19. doi: 10.1097/JSM.0000000000001294. Online ahead of print.
Authors: Brett S Pexa, Malia N M Blue, Nikki E Barczak-Scarboro, Jeffrey B Taylor, Christopher D Johnston, Kevin R Ford
Summary: The aim was to compare soreness location and intensity between male and female soccer athletes across 2 competitive seasons. Forty male and 42 female collegiate soccer athletes. Season-long soccer trainings and games were utilized. Athletes reported perceived soreness location and intensity daily. χ2 analysis and linear mixed effect models were used to compare soreness locations and intensities by sex. Male and female soccer athletes reported similar number of soreness instances, but male soccer athletes reported soreness more frequently at the ankle, foot, hip, pelvis, and posterior thigh. Female soccer athletes reported soreness more frequently at the anterior leg, anterior thigh, and knee. There was no significant difference in soreness intensity between sexes at any body location (P = 0.86). When collapsed across sex, the frequency of anterior thigh soreness was higher at preseason (7.49%, CI: 5.46-9.52) than at midseason (4.55%, CI: 2.52-6.57; t = -2.94, P = 0.023) and at postseason (3.00%, CI: 0.76-5.23; t = -3.74, P < 0.001). There was also a significant difference in hip soreness frequency between the preseason (2.35%, CI: 1.32-3.33) and the postseason time points (0.52%, CI: -0.73% to 1.67%; t = -2.68, P = 0.023). Male and female athletes differ in the locations of their lower extremity soreness. However, lower extremity soreness intensity does not differ between sexes. Soccer athletes report soreness more frequently during the preseason and midseason than during the postseason. With tools to measure daily soreness location and intensity, clinicians could create targeted interventions to reduce soreness and limit its negative affect.