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 Sex-Moderated Effects of Soccer Cleat Stud Shape and Fatigue on Traction and Knee Joint Mechanics During Lateral Cutting
Reference: J Appl Biomech. 2026 Jul 16:1-9. doi: 10.1123/jab.2025-0132. Online ahead of print.
Authors: Emily Karolidis, Michael E Hahn
Summary: Market-available soccer footwear is predominantly designed according to male athlete mechanics. With known sex differences in cutting strategies, it should not be assumed that the female body can withstand the same amount of traction as males. Mechanical stability of the lower limbs is affected by fatigue, with negative effects most pronounced in female athletes. Soccer cleats could play a key role in moderating female athletes‘ exposure to torsional injury mechanisms across game play, such as those mechanisms in anterior cruciate ligament injury. This study investigates the influence of soccer cleat stud shape, elliptical, and bladed on traction utilization and knee mechanics of male and female participants during lateral cutting before and after fatigue progression. College-aged soccer participants (10 males, 10 females) performed 2 data collections in cleated footwear of different stud shapes. Lower limb kinetics and kinematics were compared between cleats and across fatigue states. No interaction effects were found on knee mechanics, though main effects of sex and fatigue were observed. A 3-way interaction on the rate of traction utilized at initial contact was found, demonstrating the influence of fatigue and cleat on sex-specific ground interactions. Future works are warranted to understand the effect of high-performance product on female mechanics.
#2 Cognitive and Behavioral Functioning in Female Former Soccer Players: Results from the Head Impact and Trauma Surveillance Study (HITSS)
Reference: medRxiv. 2026 Jul 11:2026.02.25.26347083. doi: 10.64898/2026.02.25.26347083.
Authors: Shania C Mulayi, Anna Aaronson, Kelsey J Goostrey et al.
Summary: Repetitive head impacts (RHI) from contact and collision sports have been associated with later-life cognitive and neurobehavioral impairments, as well as neurodegenerative conditions such as chronic traumatic encephalopathy (CTE). RHI-associated clinical sequelae among female former soccer players, specifically, are not well understood. This cross-sectional study aimed to examine the relationship of RHI exposure proxies (e.g., total years of soccer play, concussion history, highest level of play, and estimated cumulative heading frequency) with clinical measures (e.g., subjective cognitive complaints, objective cognitive performance, behavioral dysregulation, and depressive symptoms) among 2,732 women, aged 40 years or above, enrolled in the Head Impact and Trauma Surveillance Study (HITSS), all of whom formerly played organized soccer. HITSS participants completed an online battery that elicited self-reported cognitive and behavioral complaints and depressive symptoms, and that assessed cognitive performing via computerized tests. Multivariable linear regression models estimated associations between soccer-related RHI proxies and outcome measures, adjusting for age and education. Among the former soccer players, longer duration of soccer play, higher level of play, greater estimated cumulative heading frequency, and concussion history were significantly associated with worse self-reported cognitive functioning, greater behavioral dysregulation, and elevated depressive symptom severity. Apart from a single association between concussion history and PAL FAMS performance, we found no other associations between RHI proxies and objective cognitive test performance. Among middle-aged women who played organized soccer, cumulative RHI exposure was associated with small but statistically significant effects for measures of subjective cognitive complaints, behavioral functioning, and depressive symptoms. Continued monitoring of this large cohort of female former soccer players will improve understanding of long-term consequences of soccer play.
#3 Fatigue-induced changes in jump and hop performance and the limited explanatory value of Fatigue Index in professional Indian male soccer players- an analytical cross-sectional study
Reference: BMC Sports Sci Med Rehabil. 2026 Jul 16. doi: 10.1186/s13102-026-01856-w. Online ahead of print.
Authors: Cyanna Joseph Dsouza, Ajay Kumar, Vijayakumar Palaniswamy, Animesh Hazari, Rajasekar Sannasi
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01856-w_reference.pdf
Summary: Fatigue can impair neuromuscular performance during sport-specific lower limb tasks. Although hop-based assessments are commonly used in sports rehabilitation and functional performance testing, rested assessments may not fully capture fatigue-related performance decline. Fatigue Index (FI) is commonly used to quantify decline in sprint performance, but its ability to explain fatigue-related changes in hop performance remains uncertain. This cross-sectional study included 195 professional Indian male soccer players who completed a vertical jump assessment using the validated MyJump2 application and standardised hop-for-distance, and side-hop tests before and immediately after a repeated-sprint ability fatigue protocol. FI was calculated as a positive sprint decrement, defined as the ratio of total sprint time to ideal sprint time, where ideal sprint time was set to the fastest sprint time multiplied by 6. Paired non-parametric analyses were employed to examine pre- and post-fatigue changes. Robust regression models were used to evaluate the independent association of FI with performance change after adjusting for age and playing experience. Sensitivity analyses using winsorised and outlier-excluded datasets assessed the stability of the estimates. Correlation network analysis was performed to explore relationships among baseline hop-performance variables. The documented FI was 7.08 ± 0.90%, indicating a physiologically plausible positive sprint-decrement value. Fatigue significantly reduced all hop and jump performance outcomes. Median jump height decreased by 4.11 cm, contact time increased by 11.63 ms, mean power decreased by 39.33 W, and reactive strength index-modified decreased by 0.02 m/s. Hop-for-distance performance decreased by approximately 6.5-7.0 cm, while side-hop performance declined by 3-4 repetitions. After adjustment for age and playing experience, FI values showed minimal independent association with most fatigue-related change outcomes. Age showed stronger and more consistent associations, particularly with contact time and the modified reactive strength index. Sensitivity analyses indicated stable findings across primary, winsorised, and outlier-excluded models. Correlation network analysis identified an explosive-performance cluster in which jump height, reactive strength index-modified, and mean power were positively associated, whereas contact time was inversely associated with these variables. Hop-performance assessment under fatigued conditions revealed a consistent decline in explosive and reactive lower limb performance in this cohort of Indian male soccer players. FI values showed limited value as an isolated explanatory metric for fatigue-related performance decline. Outcome-specific changes, particularly contact time, reactive strength index-modified, jump height, and mean power, may provide more useful information than a single fatigue metric during fatigue-inclusive functional performance assessment.
#4 Combined physical and mental fatigue induces multiplanar knee biomechanical alterations during unanticipated sidestep cutting in highly trained male soccer players: A randomized crossover trial
Reference: Phys Ther Sport. 2026 Jul 14:81:101963. doi: 10.1016/j.ptsp.2026.101963. Online ahead of print.
Authors: Weipeng Liu, Zilong Wang, Thomas Dos’Santos, Weichao Li, Weihua Zheng, Hongtao Pan, Wenhua Li
Summary: The aim was to investigate the effects of combined physical and mental fatigue (PMF) on knee biomechanics during unanticipated sidestep cutting in male soccer players. Knee angles at initial contact (IC), range of motion (ROM), peak knee moments, three-dimensional ground reaction force (GRF), weight acceptance (WA) duration, and loading rate (LR) during the WA phase. Significant fatigue condition × time interactions were observed for knee flexion (p < 0.001) and abduction angle at IC (p < 0.001), WA duration (p = 0.003), peak knee abduction moment (p < 0.001), peak vertical GRF (p = 0.014), and LR (p = 0.016). Post hoc analyses showed that PMF increased knee abduction angle at IC (p < 0.001), peak knee abduction moment (p < 0.001), peak vertical GRF (p = 0.012), and LR (p = 0.006), while decreasing knee flexion angle at IC (p < 0.001) and WA duration (p < 0.001). PMF resulted in greater alterations in knee biomechanics during unanticipated sidestep cutting compared with isolated fatigue states. These findings suggest that the combined effects of physical and cognitive fatigue should be considered when evaluating biomechanical responses during cognitively demanding motor tasks.
#5 Pelvic apophysitis and avulsion fracture treated with a regenerative combination of extracorporeal shockwave therapy and extracorporeal magnetotransduction therapy in an adolescent soccer player
Reference: Wien Med Wochenschr. 2026 Jul 16. doi: 10.1007/s10354-026-01175-2. Online ahead of print.
Author: Karsten Knobloch
Summary: Avulsion injuries of the pelvic muscles cause significant time-loss injuries, especially among adolescent soccer players. I report the case of an avulsion fracture of the anterior inferior iliac spine (AIIS) with associated significant inflammation visualized by MRI and superb microvascular imaging (SMI) Doppler ultrasonography in a 15-year-old soccer player. Regenerative treatment consisted of six combined sessions of radial pressure wave with novel burst mode (Storz Masterpuls Icon), focused extracorporeal shockwave therapy (ESWT), and extracorporeal magnetotransduction therapy (EMTT). As early as 1 week after the first combined session, a 50% reduction in inflammation was noted with SMI Doppler ultrasound, with resolution of the normal tendon insertion at 6 weeks and return to playing soccer. Combining radial pressure waves, ESWT, and EMTT in apophysitis with apophysiolysis in adolescent athletes is a reasonable regenerative noninvasive option.
#6 Cardiac Arrest in a Young Soccer Player With a Pathogenic SCN5A Variant
Reference: JACC Case Rep. 2026 Jul 15;31(28):108906. doi: 10.1016/j.jaccas.2026.108906.
Authors: Ian R Sigal, John Power, Amy R Kontorovich, Daniel Musikantow
Download link: https://www.jacc.org/doi/epdf/10.1016/j.jaccas.2026.108906
Summary: The SCN5A gene encodes the alpha subunit of the cardiac sodium channel; variants are associated with inherited cardiac diseases including long QT syndrome, sick sinus syndrome, dilated cardiomyopathy, arrhythmogenic cardiomyopathy, and Brugada syndrome. A 19-year-old male soccer player with a family history of sudden cardiac death collapsed during practice and received an automated external defibrillator shock for polymorphic ventricular tachycardia. Genetic testing identified a pathogenic SCN5A c.4222G>A (p.Gly1408Arg) variant previously associated with Brugada syndrome, although no Brugada pattern was identified on electrocardiogram. A subcutaneous implantable cardioverter-defibrillator was placed. After 8 months without arrhythmias and a reassuring exercise stress test, the patient returned to competitive sports through shared decision-making. This case highlights the value of genetic testing after unexplained cardiac arrest and challenges surrounding return-to-sport decisions in inherited arrhythmia syndromes. Consider genetic testing in cases of unexplained sudden cardiac arrest. Accessible automated external defibrillators are essential for safe athletic environments.
#7 Coil Closure of Peri-Device Leak After Left Atrial Appendage Occlusion: A „Soccer Ball“ Seal
Reference: JACC Case Rep. 2026 Jul 15;31(28):108571. doi: 10.1016/j.jaccas.2026.108571.
Authors: Arturo Giacaman, Georgi Fram, Brian O’Neill, Pedro Villablanca, Pedro Engel Gonzalez
Download link: https://pdf.sciencedirectassets.com/321622/1-s2.0-S2666084926X2023X/1-s2.0-S2666084926017304/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEL3%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEaCXVzLWVhc3QtMSJHMEUCIF0UVA3RZql1BnzZKQhFXp1En0Fi%2BXIx9wJdsNiai8uAAiEAu8EhYIJKGbmKLzMexRn0nKjqzm%2FWqWs%2FCoF4xgWqApQqvAUIhf%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FARAFGgwwNTkwMDM1NDY4NjUiDOVy0sswOO%2Bi%2BlLHqiqQBTUR87%2BmPqDZzg0Q66i8K%2FFB6%2FzgtnIKUvb5oylBoi8HPSYzEMFfrfYn0WtsHZnUt%2FazGyrUTguqIF0Ho7lMv5yvJDIExeVmbkgt5ga%2Bi%2Bap%2FbbtFLP7QyLZOfMhrQ2irBm6LqBF7cYHcV1AWdul7vduuO%2FdJhY%2Fqv52cn%2FdQcconnLVVhAaSKijJX5GKXBNe1IjMAZOa9zRv4tp0WFS3SuO3vHZzIpRrjs7Yt64vvCVQU1buOJpgXkC1wPj%2BakJq8lPUiWwqx8861Kz4TYD41jRaUgHQgTPE0%2FvWUoFlhHwirIQ4I%2FHBFHtIokO0TvvSC7MzgVnlc5h0cWaat%2FG2qxvi7OkT706ZLf5vcYK%2Bcl8JrC%2BDWi%2BuPwPZ7BEyyS9R10vQQ%2FeITzJtF8t8%2FKMOU4X8WGsTzh0n4r05tu%2FUN1YxWLq96fceoTBj7H8nayHBn5duPFAuz11OmRTVQFTC6uiUKAMLVflGCpv%2FYRTsz7aoykMpoXfMQzXs80hmN4c0JAnWL0LxxxAttYbsidbptb62mLa0UOstBX%2BEVYYWZpGkJZ8lgAY9mypQ7ibX8KU%2BjAUCIfTB0OBNMjVpxcMq1GcTA0T%2FvIlhQHFHtYhOmOxoL8VgOWRFywXUg28BUn3XKOALqmSHeptVJ1E%2FINMTtF%2FNA%2FBP6B6trKO%2Fh6K3aIgVYhiyJtMumveatoRf0pFd3Pu96DA7FHUduQRaNFnMPfNmGvOKTKEEdEG4ZjdftW0zFGV5qALkP7VwuCTq9Rq9NkLaJXk530s1PPKNwVjQZ0SpG%2B3L5slCIOAYGZu%2FTfwhY1ut6Pams8oCbo1R6gorNdYGzyJLQRkMVLPZEct%2Bl42s9kzRYI3S%2FB91oqmPJt7MJyf8dIGOrEBzYe6u5E3Sr4asLPkt3kPLIYVQ6a0O%2BNegAX776p1wGUnmnboQnGvHE78Ih9iSOTbl484q%2F86NlWjrCDHQ3Fpsdyljv3bMqUtWcZt6x2fEeeL%2FAwe6uJnmpugFyML2k4jSlKumRTgr7nQOHKedIJPjugASpAa9ji%2FfKd2VS%2BF7Z%2Fb1qg2snVT1Cqn2lGyFl0c%2BTntOJ3EAO8hBFK9ooptP3lfP69s5FfkIcyfRFRnMNqB&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20260719T050641Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTYT7ZDBIDF%2F20260719%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=6c05541a0c4f6c74408d24104424010390ff74363b09ef5749bb34de45adf268&hash=cf31ff3dec471b0e3854098033307ed63c008948295591318378c5debef62678&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S2666084926017304&tid=spdf-b33f52ef-c296-4133-b246-df5637d20158&sid=65405b2514c34446dd3b5834f454a1cfedb6gxrqa&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&rh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=1e03045105555c50075204&rr=a1d732c2db575778&cc=de
Summary: Peri-device leak after left atrial appendage closure has emerged as a clinically relevant finding, which has been associated with residual thromboembolic risk. Strategies to achieve complete seal after left atrial appendage closure (LAAC), including coil- and plug-based approaches, are increasingly being used in selected anatomies. An 82-year-old woman with paroxysmal atrial fibrillation underwent prior LAAC. Follow-up cardiac computed tomography and transesophageal echocardiography demonstrated a skirt leak caused by incomplete sealing of the inferior aspect of the device, with persistent communication between the left atrium and distal appendage lobes. Given concern for residual embolic risk, she underwent transcatheter leak closure under transesophageal echocardiography and fluoroscopic guidance using detachable coils (Ruby Coils; Penumbra). The final fluoroscopic appearance was a compact ball-like coil mass within the appendage, with complete angiographic occlusion. Multimodality imaging defined the mechanism of residual leak and guided selection of coil embolization over focal plug-based closure. In selected anatomies, coil closure alone may provide an effective solution for persistent peri-device leak. Residual peri-device leak after LAAC should be characterized mechanistically, not only by size. In anatomically selected skirt leaks, coil embolization can achieve durable closure with excellent imaging and clinical follow-up.
#8 Combined multidirectional plyometric and balance training enhances neuromuscular, postural and sport-specific performance in soccer players: a randomized controlled trial
Reference: Front Physiol. 2026 Jul 1:17:1848877. doi: 10.3389/fphys.2026.1848877. eCollection 2026.
Authors: Yazeed Nawahda, Thierry Paillard, Jamal Abubshara, Roland van den Tillaar, Mohamed Chedly Jlid
Download link: https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2026.1848877/full
Summary: This study examined the effects of combining multidirectional plyometric training with balance exercises performed on an unstable surface on neuromuscular performance, dynamic postural control, inter-limb balance asymmetry, and sport-specific motor skills in U17 soccer players. Forty-five male youth soccer players (16-17 years) were randomly assigned to a combined plyometric and balance training group (n = 15), a plyometric training group (n = 15), or a control group (n = 15). The intervention lasted 8 weeks, with three sessions per week. Assessments included squat jump, countermovement jump, drop jump, 10-, 20-, and 30-m sprint, reactive agility, Y-Balance Test performance, inter-limb asymmetry, slalom dribble, and wall-pass tests. Both experimental groups improved significantly in sprint, jump, dynamic balance, and sport-specific motor skill performance compared with the control group (p < 0.05). No significant between-group differences were found for jump performance. Reactive agility improved significantly more in the combined group than in the plyometric group. Dynamic postural control improved in both training groups, with greater gains in the combined group in the anterior and posteromedial directions for both dominant and non-dominant legs. Inter-limb asymmetry decreased in all three directions in the combined group, whereas the plyometric group improved only in the anterior and posterolateral directions. In sport-specific motor skills, both training groups improved, although no significant difference was found between the plyometric and control groups in the wall-pass test. Combined training appears to provide additional benefits for reactive agility, selected balance measures, inter-limb asymmetry and sport-specific skills in youth soccer players.
#9 The moderating role of age in the effect of hip and knee joint functions on explosive power performance in soccer players
Reference: BMC Sports Sci Med Rehabil. 2026 Jul 15. doi: 10.1186/s13102-026-01865-9. Online ahead of print.
Authors: Halil İbrahim Çakır, Recep Fatih Kayhan, Esranur Terzi, Harun Koç
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01865-9_reference.pdf
Summary: Explosive power is a key determinant of soccer performance and is closely associated with lower extremity joint function, particularly hip and knee range of motion (ROM) and muscle strength. These factors contribute to essential actions such as jumping, sprinting, and rapid changes of direction; however, their influence may vary across developmental stages due to age-related neuromuscular and physical differences. Despite existing evidence linking strength and flexibility to motor performance, the moderating role of age in these relationships remains unclear in youth soccer players. Therefore, this study aimed to investigate the effects of hip and knee joint ROM and muscle strength on motor performance and to evaluate the moderating role of age in these associations. A total of 59 male soccer players (U15: n = 14, U16: n = 15, U17: n = 15, U19: n = 15) from the youth academies of professional teams participated in the study. ROM values of the hip and knee joints, as well as quadricep and hamstring muscle strength, were measured; subsequently, motor performance assessments were conducted. The data were analyzed using multiple regression models including interaction terms with age, and regions of significance were determined using the Johnson-Neyman technique. For the reactive strength index, hip and knee ROM and quadriceps strength were identified as significant predictors; however, these effects were particularly pronounced in soccer players under the age of 17-18 (r2 = 0.076-0.239; p < 0.01). Similarly, for vertical and horizontal jump performance, hip and knee ROM, as well as quadriceps and hamstring muscle strength, were significant predictors, with these effects again being more evident in players under the age of 17-18 (r2 = 0.061-0.553; p < 0.01). Lower extremity physical characteristics influence motor performance in an age-dependent manner, with stronger effects observed in players under 17-18 years and reduced effects at older ages. These results suggest that training programs for younger age groups may benefit from incorporating range of motion and strength development alongside neuromuscular control exercises, though longitudinal research is needed to confirm causal relationships.
#10 Effects of repeated sprint training on repeated sprint ability and short-distance sprint performance in youth soccer players: a meta-analysis
Reference: BMC Sports Sci Med Rehabil. 2026 Jul 15. doi: 10.1186/s13102-026-01869-5. Online ahead of print.
Authors: Ziyi Lin, Qun Yang, Xiang Gao, Xuyan Cui
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01869-5_reference.pdf
Summary: Sprinting ability is crucial in soccer, determining a player’s performance in key scenarios such as repeated high-speed changes of direction, pressing, and tracking back. This systematic review and meta-analysis aimed to evaluate the effects of repeated sprint training (RST) on sprinting performance in youth soccer players. A systematic search was conducted across Chinese and English databases, including CNKI, PubMed, Web of Science, and Google Scholar, resulting in the inclusion of seven studies. The meta-analysis revealed that, compared to regular training, RST produced a significant improvement in RSAmean (SMD = -0.79, 95% CI: -1.40 to -0.18, P = 0.010) and short-distance sprint performance (SMD = -0.59, 95% CI: -0.92 to -0.26, p < 0.001). In contrast, the effect of RST on RSAbest (SMD = -0.08, 95% CI: -0.40 to 0.24, p = 0.60) was similar to that of regular training, with no significant difference. In conclusion, RST effectively enhances mean repeated sprint and short-distance sprint performance in youth soccer players. When implementing RST, factors such as the athlete’s age, fitness level, and training period should be taken into account.
#11 Reliability and validity of the individual GPS game data-based maximal acceleration-initial running speed regression line in youth elite soccer players
Reference: PLoS One. 2026 Jul 15;21(7):e0353385. doi: 10.1371/journal.pone.0353385. eCollection 2026.
Authors: Pascal Andrey, Karin Fischer-Sonderegger, Wolfgang Taube, Markus Tschopp
Download link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0353385
Summary: Modern load monitoring in soccer increasingly employs relative individualized acceleration intensity thresholds derived from individual maximal acceleration-initial running speed (amax-vinit) regression lines. This study examined the reliability and validity of soccer players‘ individual amax-vinit regression lines determined solely from game locomotion data. Using a GPS-based tracking system, we prospectively collected game locomotion data from 159 male youth elite soccer players over one season and repeatedly determined their amax-vinit regression lines using a recently introduced game data-based method. To examine the influence of data volume, regression lines were determined using different numbers of consecutive games. As a criterion measure, the amax-vinit regression line was determined using an acceleration test in 55 athletes. Reliability was assessed via the typical error (TE) and the intraclass correlation coefficient (ICC), and validity via the typical error of the estimate (TEE) and the Pearson correlation coefficient. The magnitude of errors and correlation coefficients was assessed using standardization and published thresholds, respectively. Reliability improved gradually with increasing data volume, resulting in TEs of 3.4% (amax intercept), 7.3% (vinit intercept), and 10.3% (slope). Nonetheless, all TEs were large in magnitude, and ICCs very low to low. Validity was unaffected by data volume, with TEEs consistently ~7% (amax intercept), ~ 12% (vinit intercept), and ~17% (slope). All TEEs were assessed as extremely large, and Pearson correlations as impractical. These findings indicate that the game data-based method currently lacks the precision required for individual-level applications, and this limitation cannot be resolved simply by including more games. Therefore, establishing relative individualized acceleration intensity thresholds within a team still requires a test-based approach. Moreover, the results suggest that properties inherent in GPS-based game locomotion data, rather than data volume, underlie the observed imprecision. We propose that substantial future improvements will depend on more precise tracking systems.
#12 Is Non-dominant Leg a Key Factor for Endurance Performance in Male Youth Soccer Players? Data-Driven Knowledge-Adjusted Causal Analysis and Literature Synthesis
Reference: Sports Med Open. 2026 Jul 15;12(1):99. doi: 10.1186/s40798-026-01076-z.
Authors: Magdalena Mikielewicz, Kacper Korzeniewski, Robert Makuch, Jakub S Gąsior, Marcel Młyńczak
Download link: https://link.springer.com/content/pdf/10.1186/s40798-026-01076-z.pdf
Summary: Soccer performance in youth players arises from a complex interaction of anthropometric, physiological, technical, and maturational factors. However, most studies emphasize correlation analyses, offering limited insight into causal mechanisms that shape athletic development and physical performance. This study aimed to identify causal pathways underlying potential targets for practical intervention in male youth soccer players. Data from 275 male Caucasian youth soccer players aged 8-18 years from youth soccer academy (Mazovian region) were collected during the pre-season and analyzed using the Greedy Fast Causal Inference algorithm to generate a data-driven directed acyclic graph. Complementarily, a scoping review of publications indexed in PubMed and Web of Science (search conducted up to July 2025) identified 102 eligible studies on associations between parameters in apparently healthy male youth soccer players. Data from studies were used to construct a chord diagram illustrating associations among players‘ characteristics. This approach revealed sprint ability, countermovement jump, agility as well as maturity as central nodes in performance networks. However, causal modeling and literature synthesis highlighted the non-dominant leg and functional deficits as a potentially modifiable determinants linked to sport-specific skills and endurance-related performance. The integration of data-driven causal discovery and review-based associations offers a methodological bridge from observational evidence toward hypothesis generation. The findings establish a rationale for a future randomized controlled trial aimed at testing whether intervention focused on reducing interleg asymmetries (i.e., differences in power/strength between lower extremities) can improve endurance capacity and specific soccer skills in male youth soccer players.
#13 Assessing Isometric Hip Adductor and Abductor Strength in Elite Youth Soccer Players: Does Hip-Flexion Angle Matter?
Reference: J Strength Cond Res. 2026 Jul 15. doi: 10.1519/JSC.0000000000005482. Online ahead of print.
Authors: Jonathan M Taylor, Hermes Pallotta, Alastair Hamilton, Craig Tears, Matthew D Wright
Summary: Isometric hip strength is a risk factor for hip and groin injuries in soccer and is assessed at various short lever positions (i.e., a hip-flexion angle of 45-90°). In this study, the effects of hip-flexion angle on peak adduction and abduction force, adduction-to-abduction ratio (ADD:ABD), and relationship between test positions were assessed. Twenty-four male soccer players (age 17.4 ± 0.8 years) completed 3 testing sessions across 2 weeks, during which peak adduction and abduction force and ADD:ABD were assessed at 45-, 60-, and 90° of hip flexion on a fixed frame dynamometer. Players completed three 5-second maximal voluntary contractions in each position, and the tests were completed in counterbalanced order. Robust repeated measures ANOVAs were used to compare peak force and ADD:ABD between positions, with significance set at p < 0.05. Pearson’s correlations were used to quantify associations between peak force on each test. Significant differences were observed in adduction between 45 and 60° (right -25.9 ± 23.1 N [±95% confidence limit]; left -33.4 ± 19.1 N); 45 and 90° (right 46.8 ± 23.2 N; left 32.6 ± 19.9 N) and 60 and 90° (right 72.7 ± 22.9 N; left 66.1 ± 19.9 N). Significant differences were also observed in abduction between 45 and 90° (right 32.2 ± 20.8 N; left 25.7 ± 21.1 N) and 60 and 90° (right 42.4 ± 20.9 N; left 41.6 ± 21.3 N). Very large correlations between tests were observed in adduction and abduction, respectively (r = 0.77-0.87). However, prediction errors were also large (∼40 N). Adduction-to-abduction ratio was highest at 60° (1.10). In conclusion, peak adduction and abduction force vary between short lever testing positions. Although strong associations between testing positions exist, large prediction intervals are evident, and these tests should not be used interchangeably.
#14 Exercise-induced fatigue and soccer kicking performance: a systematic review and meta-analysis of performance outcomes and contextual moderators
Reference: Front Physiol. 2026 Jun 30:17:1818415. doi: 10.3389/fphys.2026.1818415. eCollection 2026.
Authors: Wenkang Peng, Yecheng Zhang, Dantang Wang, Hugo Sarmento, João Paulo Vilas-Boas, João Ribeiro
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13364601/pdf/fphys-17-1818415.pdf
Summary: The effects of exercise-induced fatigue on soccer kicking performance remain inconsistent across studies and performance metrics, suggesting that fatigue-related impairments may depend on contextual and task-related factors. This systematic review and meta-analysis aimed to quantify the effects of exercise-induced fatigue on ball velocity, kicking accuracy, and lower-limb kinematics, and to examine whether selected fatigue protocol, task instruction, and player-level factors explained between-study variability in these effects. PubMed, Scopus, SPORTDiscus, and Web of Science were searched from inception to April 2025 and updated in December 2025. Experimental studies in male outfield players with pre-post fatigue comparisons were included. Random-effects meta-analyses (Hedges‘ g) and predefined subgroup analyses were conducted. Within-participant pre-post correlations were extracted, derived, or imputed, and sensitivity analyses were conducted using alternative correlation assumptions. Risk of bias was assessed using RoBANS-2 and certainty of evidence using GRADE. Thirty-five studies (733 players) were included in the systematic review, and 31 were meta-analysed. Exercise-induced fatigue was associated with lower ball velocity (Hedges‘ g = -0.589, 95% CI: -0.789 to -0.388; p <.001; I² = 72.2%; low certainty) and a smaller reduction in kicking accuracy (g = -0.265, 95% CI: -0.449 to -0.081; p = .005; I² = 58.2%; low certainty). Foot velocity also showed a negative pooled effect (g = -0.348, 95% CI: -0.618 to -0.078; p = .012), but certainty was very low. Hip, knee, and ankle angular velocities showed no clear pooled changes. Formal subgroup tests suggested moderation by kicking instruction for ball velocity and by fatigue protocol for kicking accuracy; no significant between-subgroup differences were found for player level or the remaining tested subgroup comparisons. Exercise-induced fatigue was associated with reduced soccer ball velocity and a smaller, less certain reduction in kicking accuracy. Evidence for reduced foot velocity was tentative, whereas evidence for changes in hip, knee, and ankle angular velocities was very uncertain. Contextual variation was partly supported, particularly for kicking instruction and fatigue protocol, but should be interpreted cautiously given heterogeneity and low or very low certainty of evidence.
#15 Adapting a Foundation Monocular Depth Model for Soccer Video: From Synthetic Supervision to Match-Level Reliability
Reference: Sensors (Basel). 2026 Jul 2;26(13):4192. doi: 10.3390/s26134192.
Authors: Ju-Seong Do, Ho-Young Jung
Download link: https://www.mdpi.com/1424-8220/26/13/4192
Summary: Soccer-video analysis centers on pitch-plane tracking, but camera-view depth cues such as occlusion and goal-area structure are not fully represented on the field plane. Synthetic benchmarks provide dense supervision unavailable for real broadcasts, but whether adaptation yields predictions that are reproducible across matches and operationally feasible remains unclear. We evaluate a Depth Anything V2 model adapted to SoccerNet-Depth with four components: Unaligned MDE accuracy, scale-and-shift aligned diagnostic, match-to-match reliability, and accuracy-cost trade-off. The model achieves an unaligned validation AbsRel of 0.00372. The aligned diagnostic shows that Base DAv2 retained substantial scene-depth structure, whereas SoccerNet adaptation enabled direct compatibility with the normalized target without per-frame ground-truth fitting. Relative to the VKITTI-fine-tuned reference, the adaptation improved all eight metrics in all 21 validation matches, with paired Wilcoxon tests significant after Bonferroni correction. On the challenge split, it reduced AbsRel by 34.1% versus the official baseline. The higher-resolution configuration improved the validation AbsRel by 5.9%, while the default retained a better accuracy-cost balance. At 401.57 ms per frame, the default is suited to post-match analysis, not live or near-real-time use. The study contributes a benchmark-scoped adaptation case study and protocol for foundation MDE on SoccerNet-Depth.
#16 The impact of COVID-19 on soccer players‘ health: A systematic review and meta-analysis
Reference: Int J Sports Med. 2026 Jul 14. doi: 10.1055/a-2896-9130. Online ahead of print.
Authors: Carlos H Almeida, Rui Freitas, José Afonso et al.
Summary: Despite growing research, the health effects of COVID-19 on soccer players remain poorly integrated. This meta-analytic review synthesized evidence across competitive levels and pandemic phases to characterize the effects of SARS-CoV-2 infection and pandemic-related restrictions. The study adhered to PRISMA 2020 and Cochrane standards, with searches conducted in PubMed, Scopus, SPORTDiscus, and Web of Science. Eligibility criteria followed the P.E.C.O.S. framework. From 6,048 records screened, nine studies (>1,525 players from Tiers 1-5) met the inclusion criteria. These observational investigations included predominantly male samples (94.2%) and assessed cardiovascular, respiratory, endocrine, metabolic/biochemical, hematologic, anthropometric, musculoskeletal, and gastrointestinal outcomes. Comparisons between pre- and during-pandemic periods suggested preserved cardiac integrity with infrequent post-infection sequelae, alongside mild pulmonary effects in infected players that tended to resolve with training resumption. Amid inconsistent endocrine findings, testosterone-to-cortisol ratios declined in non-infected players. Metabolic, hematologic, and anthropometric parameters were mostly stable, whereas hemoglobin exhibited a significant pooled increase. Musculoskeletal and gastrointestinal data were insufficient for broad conclusions. Moreover, meta-analytic estimates require cautious interpretation owing to few studies and very low certainty. Altogether, COVID-19 was associated with modest and mostly reversible effects, with structured home-based training potentially offsetting detraining. Rare cardiac abnormalities still warrant careful medical supervision.
#17 Sustained participation deficits following anterior cruciate ligament reconstruction in elite male soccer players globally
Reference: Knee Surg Sports Traumatol Arthrosc. 2026 Jul 14. doi: 10.1002/ksa.70537. Online ahead of print.
Authors: Haneef Khan, Amina Khan, Ashley Rosenberg, Stephen Marcaccio
Summary: Anterior cruciate ligament (ACL) injuries have been associated with reduced career longevity and decreased match participation in professional soccer players. Minutes played per match (MPM) offers an objective, normalised metric that captures not only return-to-play success but also the degree of sustained participation in competitive matches. This study sought to evaluate changes in match participation before and after ACL reconstruction in elite soccer players using MPM and related participation metrics. Player and match data were sourced from Transfermarkt.com. Professional soccer players from first or second-tier leagues globally who sustained ACL injuries between January 2007 and December 2022 with reported absence greater than 90 days were identified. The date of injury was considered ‚time zero‘. Year -1 corresponds to the 360 days preceding injury, and Year 1 to the interval between 361 and 720 days after injury. The primary outcome was MPM, calculated as total minutes played divided by number of appearances. The primary analysis compared MPM between Year -1 and Year 1 in players who returned to play with at least five appearances in Year -1 and 3 appearances in Year 1. Statistical significance was set at p < 0.05. After applying exclusion criteria, 9071 ACL injuries in 8022 unique players were included. Of these, 7172 injuries (79.1%) resulted in successful return to professional play, with mean time to return of 255.7 days. For the primary analysis, 4596 players with adequate match participation data were included. Mean MPM decreased significantly from 67.4 ± 19.3 min in Year -1 to 56.5 ± 23.3 min in Year 1 (p < 0.001), representing a mean reduction of 10.8 min (16.1% relative decrease) with moderate effect size (Cohen’s d = 0.51). Median MPM decreased from 72.1 min to 59.8 min. Mean appearances per year decreased from 21.5 to 14.7, and total minutes played per year decreased from 1527 to 924. While 79.1% of elite soccer players return to professional play following ACL reconstruction, there is a significant and clinically meaningful reduction in match participation as measured by MPM. Athletes and clinicians should be counselled regarding realistic expectations for post-ACLR participation levels.
#18 Athletic performance levels across biological maturity status in youth soccer players
Reference: Front Sports Act Living. 2026 Jun 22:8:1856821. doi: 10.3389/fspor.2026.1856821. eCollection 2026.
Authors: Giuseppe Scardina, Guglielmo Pillitteri, Domenico Savio Salvatore Vicari et al.
Summary: Biological maturation can produce substantial inter-individual variability in physical performance among youth soccer players. However, whether its influence differs in magnitude across physical domains has been little examined within a testing battery. Forty-four youth male soccer players (13.12 ± 1.75 years; U13-U16) were assessed for countermovement jump (CMJ) height, lower limb peak power, sprint speed over 10 and 30 m (reflecting acceleration and maximal velocity, respectively), and VO2max. Predicted maturity status was classified into pre-, circa-, and post-PHV (peak height velocity) groups using the modified Mirwald equation. Group differences were analyzed using the one-way ANOVA. Post-PHV group outperformed both pre- and circa-PHV groups across all outcomes (p ≤ 0.05). Effect sizes were large in all outcomes, and the most significant were recorded for lower limb peak power (ε2 = 0.73), followed by 30-m sprint (η2 = 0.63), 10-m sprint (η2 = 0.51), VO2max (ε2 = 0.51), and CMJ height (η2 = 0.40). Maturity status is associated with large performance advantages across all tested domains in youth soccer players. Post-PHV players demonstrated significantly higher performance in jumping, sprinting, aerobic capacity, and lower limb peak power and support the integration of predicted maturity assessments in physical profiling, training program design, as well as for facilitating talent identification.
#19 Mechanisms and situational patterns of anterior cruciate ligament injuries in professional women’s football (soccer): A systematic video analysis across 25 leagues (2022-2024)
Reference: Knee Surg Sports Traumatol Arthrosc. 2026 Jul 13. doi: 10.1002/ksa.70528. Online ahead of print.
Authors: Wyatt Hampstead, Ric Lovell, Matthew Whalan et al.
Download link: https://esskajournals.onlinelibrary.wiley.com/doi/epdf/10.1002/ksa.70528
Summary: The aim was to identify and describe the biomechanical characteristics and football-specific contextual factors associated with anterior cruciate ligament (ACL) injuries in professional women’s football. A media-based prospective cross-sectional study identified 247 ACL injuries across international matches and 25 national women’s leagues (tiers 3-5) between 2022 and 2024 using a validated media-based surveillance approach. Video footage was available for 127 injuries and analysed by three reviewers using Quality Appraisal for Sports Injury Video Analysis Study (QA-SIVA) informed protocols and frame-by-frame analysis. Situational variables included player action (e.g., pressing, tackling, landing, kicking), contact mechanism, match status, positional role, playing surface, competition, pitch location and time of injury. Most injuries (67%) occurred within the first 45 min and during defensive play (65%). Mechanisms were non-contact (49%), indirect contact (41%) and direct contact (10%). Frequent scenarios included pressing/tackling (53%), being tackled (15%), regaining balance after kicking (7%) and landing from a jump (5%). Among the biomechanical subsample (57 frontal/transverse and 46 sagittal cases), commonly observed patterns during pressing or tackling included ~50° hip flexion, ~25° knee flexion, a neutral trunk position (~0°), hip abduction (66%) and knee valgus (54%). ACL injuries in professional women’s football frequently occurred during defensive actions early in matches. Within the biomechanical subsample, these injuries commonly involved limited lower-limb flexion and valgus knee alignment, although findings should be interpreted cautiously due to the limited sample size. Together, these findings provide descriptive insight into common injury scenarios in professional women’s football and may help inform future prevention strategies and targeted biomechanical research.
#20 Energy intake and expenditure of Japanese male soccer, long-distance running, and road cycling athletes across multiple teams
Reference: Phys Act Nutr. 2026 Jun;30(2):53-62. doi: 10.20463/pan.2026.0020. Epub 2026 Jun 30.
Authors: Naoki Nakamura, Satoko Ozawa, Soshi Tokiwa et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13358611/pdf/pan-2026-0020.pdf
Summary: This study aimed to estimate the energy expenditure, intake, and balance of Japanese athletes to assess their intake of carbohydrate, protein, and fat as energy sources. Ninety male soccer players, long-distance runners, and road cyclists who belonged to multiple teams were included in this study. The study period covered one training day and one rest day. The energy, carbohydrate, protein, and fat intakes were assessed using food photographs and food records. Energy expenditure was calculated using metabolic equivalent and physical activity level based on practice questionnaires. Energy balance was calculated by subtracting the energy expenditure from the energy intake. The median values (25th-75th percentile) for energy balance on training day were negative: soccer, -767 (-1,079-98) kcal/day; long-distance running, -367 (-907-169); and road cycling, -948 (-2,577-329). The median daily carbohydrate intake were 5.0 (4.3-6.2), 6.4 (5.2-7.1), and 8.3 (6.6-10.0) g/kg for soccer, long-distance running, and road cycling, respectively. Our results indicated that the energy balance on training day may have been negative for the Japanese soccer players, long-distance runners, and road cyclists. Considering training time, carbohydrate intake was insufficient or tended to be insufficient compared to the recommended amounts for athletes. These findings should be incorporated into the development of nutritional support strategies.
#21 Injury characteristics and cost of ankle sprains in amateur soccer (football): a national analysis involving 3 years of Australian insurance data
Reference: Sci Med Footb. 2026 Jul 12:1-14. doi: 10.1080/24733938.2026.2701683. Online ahead of print.
Authors: Andrew G Ross, Patrick Rowe, Rees Thomas
Summary: This national retrospective analytical cross-sectional study investigated the injury characteristics and insurance costs associated with ankle sprains in Australian amateur soccer (football). Three years of insurance records (2018-2020) were analysed to describe claim characteristics, costs, and mechanisms of injury, stratified by sex and age group (junior: 7-17 years; senior: 18-34 years; veteran: 35+ years). Categorical variables were presented as frequencies and percentages and compared using Chi-squared or Fisher’s exact tests, while cost data were reported as means ± standard deviation (SD) with 95% confidence intervals (CI). Across three football seasons, 749 ankle sprain claims were reported, with a total insurance cost of AU$1,727,858 and a mean cost of AU$2,307 per claim. Indirect costs (AU$1,117,711) accounted for 65% of total expenditure and were six-fold higher than direct medical costs. Male players were responsible for 80% of total costs, reflecting higher claim numbers, while senior players (18-34 years) contributed 74% of the financial burden. Syndesmosis sprains were uncommon (3%) but had the highest mean cost (AU$7,690). Direct contact (56%) was the most common injury mechanism, although non-contact sprains incurred higher mean costs. No significant sex-based differences were observed in injury characteristics; however, junior players sustained proportionally more tackle-related sprains and fewer non-contact sprains than senior or veteran players. Ankle sprains impose a substantial economic burden within the insurance-covered costs captured in this dataset in amateur football, driven primarily by indirect costs. The disproportionate cost of syndesmosis and non-contact injuries identifies key areas for prevention and provides data for future economic evaluations in football.
#22 Acute effects of plyometric-dynamic stretching sequencing on athletic and neuromuscular performance in soccer players: a randomized crossover trial
Reference: BMC Sports Sci Med Rehabil. 2026 Jul 11. doi: 10.1186/s13102-026-01873-9. Online ahead of print.
Authors: Sedat Özcan, Bogdan Antohe, Doğukan Hakan Atceken et al.
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01873-9_reference.pdf
Summary: Dynamic stretching (DS) and plyometric exercises are commonly incorporated into warm-ups to acutely enhance athletic performance through increased range of motion, reduced muscle stiffness, and post-activation performance enhancement. However, the optimal sequencing of these two modalities prior to sport-specific activities remains unclear. This randomized crossover trial compared the acute effects of DS followed by vertical drop jumps (DJ) versus the reverse sequence on key athletic and neuromuscular performance outcomes in male amateur soccer players. Twenty male amateur soccer players (age 20.5 ± 1.7 years; height 176.6 ± 4.3 cm; body mass 71.9 ± 4.6 kg) completed three conditions in counterbalanced order: DS + DJ, DJ + DS, and a control condition (CC) consisting of standard dynamic activities only. Each session was separated by a minimum of 72 h. Outcomes included L-drill maneuverability, modified repeated sprint ability (RSA) total time and fatigue index, 10 m linear sprint speed, countermovement jump (CMJ) height, and standing broad jump distance. Significant Condition × Time interactions favored the DS + DJ sequence for L-drill agility (η² = 0.43, p < 0.001), 10 m sprint (η² = 0.35, p = 0.002), CMJ height (η² = 0.28, p = 0.002), and standing broad jump (η² = 0.18, p = 0.03). DS + DJ produced significant improvements from pre- to post-warm-up in L-drill (Δ = – 0.15 s, d = 0.78), 10 m sprint (Δ = – 0.05 s, d = 0.65), CMJ height (Δ = +1.23 cm, d = 0.29), and broad jump distance (Δ = +4.20 cm, d = 0.38). By contrast, neither DS + DJ nor DJ + DS enhanced RSA total time or fatigue index (both p > 0.05). Performing DS before plyometric conditioning improves single-effort sprinting, jumping, and pre-planned change of direction but not repeated sprint ability. Coaches should use DS + DJ sequencing to acutely enhance neuromuscular performance in soccer players.
#23 Cam morphology in Japanese adolescent male football player: a prospective study with 3-year follow-up
Reference: BMC Sports Sci Med Rehabil. 2026 Jul 17. doi: 10.1186/s13102-026-01862-y. Online ahead of print.
Authors: Ryota Yamamoto, Wataru Sakamaki, Toshiharu Tsutsui, Suguru Torii
Download link: https://link.springer.com/content/pdf/10.1186/s13102-026-01862-y_reference.pdf
Summary: Cam morphology developed during adolescent increases the risk of hip osteoarthritis by 4.3-6.2-fold over 5 and 10 years. Although cam morphology are believed to occur during the growth period, when significant physical changes take place, no studies have examined the relationship with physical maturation indicators. The aim of this study was twofold: (1) to examine the prevalence of cam morphology in Japanese adolescent football players.; (2) to investigate if cam morphology development is associated with peak height velocity age(PHVA) status. Fifty-seven adolescent male football players (114 hips) were prospectively 1enrolled. Hip morphology was assessed using dual-energy X-ray absorptiometry at baseline and at 1- and 2-year follow-up. Participants with missing data, longitudinal height records required for estimating peak height velocity age (PHVA), were excluded. Consequently, 47 participants (94 hips) were included in the final analysis. Cam morphology on these time points was defined as: (A) visual scores of the anterior head-neck junction, classified as: (1) normal, (2) flattening, and (3) prominence. We calculated the years from age at PHV of each participant by subtracting the chronological age from the age at PHV to determine the period until the peak of growth. Cam morphology based on visual scores was found in 79 of 94 hips(84.0%, 39 kicking leg, 40 shaft leg)at in 2-year follow-up. non-association between cam morphology development based on visual scores and PHVA status (OR = 1.08, 95% CI 0.81-1.52, p = 0.517). Although previous studies have suggested a lower prevalence of cam morphology in East Asian football players than in Western populations, we observed a relatively high hip-level prevalence of DXA-defined cam morphology, increasing from 53.2% (50/94 hips) at baseline to 84.0% (79/94 hips) at the 2-year follow-up, in this cohort of 47 Japanese adolescent football players. In addition, cam morphology developed both before and after peak height velocity age (PHVA), indicating that its development is not confined to a specific stage of biological maturation.
#24 Dominant and Nondominant Side Patterns in Hamstring Stiffness and Clinical Flexibility in Amateur Football Players and Healthy Controls
Reference: Eur J Appl Physiol. 2026 Jul 17. doi: 10.1007/s00421-026-06355-x. Online ahead of print.
Authors: Numan Mercan, Nurzat Elmali, Serdal Çitil, Kerem Bilsel, İbrahim Tuncay
Summary: Football-specific loading may be associated with different dominant and nondominant (D and ND) side patterns in hamstring stiffness and clinical flexibility. This study compared D and ND side patterns in semitendinosus (ST), semimembranosus (SM), and biceps femoris (BF) stiffness and in active knee extension (AKE) and straight leg raise (SLR) measurements between amateur football players and healthy controls. This cross-sectional study included 50 amateur football players and 50 healthy controls without organized athletic participation. Bilateral ST, SM, and BF stiffness values were measured using shear wave elastography (SWE). Clinical hamstring flexibility was assessed with AKE and SLR tests. D and ND side differences were examined within each group, and side difference patterns were compared between groups. In football players, SM stiffness was higher on the dominant side (D-ND estimate, 1.25 kPa, p = 0.012). In controls, BF stiffness was higher on the nondominant side (D-ND estimate, – 0.90 kPa, p = 0.044). In the primary between group comparison, only the BF D-ND difference differed significantly, with opposite directions of side difference between groups (between group estimate, 1.74 kPa, p = 0.013). Controls also showed dominant side AKE and SLR differences of 1.00° and 1.50°, both below reported measurement error thresholds. D and ND side patterns in hamstring stiffness and clinical flexibility varied according to the muscle, test, and group studied. The main between group difference emerged through BF stiffness, whereas the AKE and SLR differences observed in controls were limited in magnitude.
#25 Discrete Symmetry Metrics Mask Frequent Phase-Specific Lower Limb Asymmetry During Bilateral Countermovement Jumping in Youth Football Players
Reference: Scand J Med Sci Sports. 2026 Jul;36(7):e70350. doi: 10.1111/sms.70350.
Authors: Mark G L Sayers, Chloe Keogh, Kelly S Jensen, Bruno P Couto
Summary: Inter-limb asymmetry is frequently evaluated during bilateral tasks such as the countermovement jump (CMJ), typically using discrete peak-based metrics. However, these approaches may inadequately capture the complex, time-varying nature of inter-limb coordination. This study examined inter-limb asymmetry during CMJ in youth football players using both discrete and continuous assessments, with consideration of limb dominance. Forty-three male youth academy football players (14 ± 1.1 years) performed three maximal bilateral CMJs with data collected using dual force platforms and three-dimensional motion capture. Inter-limb asymmetry was quantified using discrete symmetry indices for peak vertical ground reaction force (GRFvert), joint displacements, and joint moments, alongside time-series approaches including statistical parametric mapping (SPM1D) and the normalized symmetry index (SInorm). Asymmetry threshold breaches (±10% and ±20%) and their duration across the movement cycle were assessed, with comparisons between dominant and non-dominant limbs. Discrete metrics indicated low levels of inter-limb asymmetry at the group level, with mean values typically within ±10% thresholds. In contrast, time-series analyses revealed frequent, phase-specific asymmetry within individual trials, particularly for joint moments, despite no significant group-level differences identified using SPM1D. A ±10% GRFvert asymmetry breach occurred in every trial. Limb dominance had minimal influence, except for longer GRFvert breach durations on the non-dominant limb. Inter-limb asymmetry during bilateral CMJ is observed frequently when assessed using time-series methods, despite apparently symmetrical discrete outcomes. These findings demonstrate that reliance on peak-based symmetry metrics may overlook substantial phase-specific asymmetry, with implications for the interpretation of bilateral loading during athlete monitoring and rehabilitation contexts.
#26 Premature Ventricular Contractions as a Result of Subacute Myocarditis in a Professional Football Player
Reference: JACC Case Rep. 2026 Jul 15;31(28):108864. doi: 10.1016/j.jaccas.2026.108864.
Authors: Charlotte Pirquet, Daniel Underberg, Brian Osler, Derek Schwabe-Warf, David Shipon
Summary: Return-to-play (RTP) decisions for professional athletes with arrhythmias are challenging, particularly when the diagnosis is uncertain. A 33-year-old professional football player presented for RTP evaluation of premature ventricular contractions (PVCs) and atypical chest pain. Work-up was significant for fragmented R waves and PVCs on electrocardiogram as well as late gadolinium enhancement on cardiac magnetic resonance imaging. Positron emission tomography scan was normal. These findings suggested possible subacute myocarditis. He elected to rest for 2 to 3 months and was treated with guideline-directed medical therapy. Risk stratification highlighted increased risks associated with late gadolinium enhancement and incomplete genetic evaluation, though PVC morphology and normal positron emission tomography scan supported a favorable risk profile. This case underscores the complexity of RTP decisions in athletes with arrhythmias of uncertain etiology, emphasizing individualized evaluation. Real-world RTP decisions often do not align with diagnostic pathways; clinicians must integrate clinical data, athlete goals, and evolving evidence.
#27 Scan frequency and timing in relation to performance in elite youth female football players during 11v11 match play
Reference: Front Sports Act Living. 2026 Jul 1:8:1853406. doi: 10.3389/fspor.2026.1853406. eCollection 2026.
Authors: Livio Abächerli, Jörg Fuchslocher, Michael Romann, Mirjam Hintermann
Download link: https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2026.1853406/full
Summary: In the fast-changing game of football, effective scanning is crucial to performance, as it enables players to gather essential information about their surroundings. Therefore, this study expands the current understanding of scanning by investigating the influence of scanning frequency (SF) before ball reception (SFb) and during ball possession (SFd), as well as scan timing on subsequent pass and dribbling performance, while controlling for opponent pressure and interindividual differences. 39 female players (age: 17.45 ± 0.88 years) from two elite teams in the Swiss U19 women’s national league were recorded during two official 11v11 championship matches. Scanning behavior was assessed through video analysis. A scan was defined as an active, self-initiated head movement away from the ball. In total, 819 events, defined as the last 10 s before ball reception until the execution of the subsequent action, were identified and examined using multilevel logistic regression models. The multilevel logistic regression models indicated that, while SFd was positively associated with subsequent passing success [OR = 1.09, 95%-CI(1.03, 1.15), z = 3.22, p = 0.001], SFb showed no significant association [OR = 1.07, 95%-CI(0.99, 1.16), z = 1.78, p = 0.075]. Neither SFd nor SFb were significantly associated with dribbling success. Direct play was positively associated with tighter opponent pressure but not SFb. Scan timing showed no significant associations with any performance indicator. This is the first field-based study to examine multiple scanning predictors in relation to performance during 11v11 matches in female players, while accounting for opponent pressure and interindividual differences. SFd and opponent pressure were identified as key factors in understanding scanning behavior in women’s 11v11 football. These findings emphasize the importance of research on female players.
#28 Transcriptomic Profiling of the Biceps Femoris Long Head 72 h Following a Football Match and Associations With Recovery Biomarkers
Reference: Scand J Med Sci Sports. 2026 Jul;36(7):e70339. doi: 10.1111/sms.70339.
Authors: Pedro L Cosio, Iago Pinal-Fernandez, Lia Moreno-Simonet et al.
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13371843/pdf/SMS-36-e70339.pdf
Summary: This secondary integrative analysis of a previously published cohort investigated the molecular pathways underlying muscle recovery of the biceps femoris long head (BFLH) after a football match, by integrating newly generated transcriptomic data with clinical recovery markers over a 72-h recovery period. BFLH muscle biopsies from 10 male, regional-first division football players were obtained 7 days before a football match (MD-7) and 3 days post-match (MD+3). The final sample included 9 participants because 1 biopsy provided insufficient material for sequencing. Bulk RNA-sequencing was conducted to analyze differential gene expression considering Benjamini-Hochberg correction. Pathway enrichment analyses were conducted to identify biological processes altered between pre- and post-match conditions. Clinical markers, including creatine kinase (CK), hamstring rate of torque development (RTD), and sprint performance, were assessed before the match (MD) and at 24 (MD+1), 48 (MD+2), and 72 h (MD+3) post-match. Correlations between transcriptomic and clinical variables were calculated using Spearman’s rank correlation. MYH1 was the most responsive gene, showing significant downregulation at MD+3 (log2FC = -1.116, q-value = 3.8 × 10-2). Pathway analyses identified 440 transcriptomic signatures at MD+3, reflecting stress response, immune and cytokine signaling, protein turnover, and structural remodeling. Changes in clinical variables during recovery were associated with coordinated expression shifts across genes related to different phases of the muscle damage-regeneration continuum, including muscle contraction, damage control, protein turnover, repair signaling, and myogenic regeneration. BFLH is not fully recovered 3 days after a football match, as evidenced by sustained downregulation of MYH1, pathway enrichment, and associations with clinical markers. Molecular recovery processes extend beyond 72 h, suggesting this period is insufficient for complete BFLH recovery in football players.
#29 Psychosocial correlates of children’s football participation: a psychological network analysis of parental support, stereotypes, and dualistic passions
Reference: Front Psychol. 2026 Jul 1:17:1897362. doi: 10.3389/fpsyg.2026.1897362. eCollection 2026.
Authors: Xiancheng Zeng, Min Hu, Wei He, Zechen Xie
Download link: https://pmc.ncbi.nlm.nih.gov/articles/PMC13368343/pdf/fpsyg-17-1897362.pdf
Summary: Football serves as a premier platform for youth development, yet gender-based participation gaps remain a persistent challenge within the global sporting landscape. Drawing on Ecological Systems Theory as a conceptual framework, this study utilized psychological network analysis to examine selected psychosocial factors related to football participation among primary school students. The sample comprised primary school students (M = 9.322, SD = 0.677, age range = 8 to 13 years). We employed psychological network analysis with the Network Comparison Test for network estimation and gender comparisons. Harmonious passion emerged as the most central node across both construct and item level networks, showing strong connections to parental support and behavioral engagement. While the Network Comparison Test confirmed a largely invariant psychosocial architecture across genders, exploratory analysis revealed localized descriptive variations: obsessive passion items occupied more central positions in girls‘ networks, whereas gender stereotypes were more prominent in boys‘ networks. These findings indicate that harmonious passion occupies a central position in the network structure of children’s football participation. This study underscores the need for interventions that prioritize autonomous motivation while addressing the subtle, gender-specific nuances within children’s sporting environments.
#30 Return to Sport After Arthroscopic Bankart Repair in Professional Male Football Players
Reference: J Clin Med. 2026 Jul 6;15(13):5259. doi: 10.3390/jcm15135259.
Authors: Yener İnce, Muhammed Yusuf Afacan, Goker Utku Deger, Tolgahan Korkmaz
Download link: https://www.mdpi.com/2077-0383/15/13/5259
Summary: Traumatic anterior shoulder instability is a clinically relevant problem in professional football (soccer) players, for whom restoration of shoulder function, postoperative stability and timely return to sport are critical. Despite a growing body of evidence supporting arthroscopic Bankart repair in athletic populations, data on sport-specific outcomes in professional male football players remain limited. Twenty-two professional male football (soccer) players who underwent arthroscopic Bankart repair following first-time anterior traumatic shoulder instability between 2011 and 2021 were retrospectively analyzed. No control group was included. The Rowe score and American Shoulder and Elbow Surgeons (ASES) score were assessed preoperatively and at 12 months postoperatively. Return-to-sport time was defined as the time from surgery to return to competitive match play and was recorded in weeks. Recurrent instability was assessed throughout the follow-up period. IBM SPSS Statistics, v27 was used for statistical analyses. The median age was 25 years old (15-34). The right shoulder was involved in 15 patients (68%) and the left in 7 (32%). The median time to return to sport was 18 weeks (range, 14-25). During a median follow-up of 6.5 years (range, 4-14), recurrent instability occurred in one patient (4.5%) at 14 months after surgery. After surgery, both functional scores improved significantly. The median preoperative Rowe score increased from 55 (range, 35-60) to 100 (range, 85-100) (p < 0.001), and the median ASES score improved from 55 (range, 40-68) to 100 (range, 85-100) (p < 0.001) at 12 months. Postoperative ASES and Rowe scores were positively correlated (r = 0.666, p = 0.001). Neither score was significantly associated with return-to-sport timing. In this retrospective series of professional male football players with first-time anterior shoulder instability, arthroscopic Bankart repair was associated with significant improvements in 12-month Rowe and ASES scores, a median return-to-sport time of 18 weeks, and a low observed recurrence rate during long-term follow-up. These findings should be interpreted within the context of the study’s retrospective design and limited sample size.
#31 Injury Profile in German Amateur Women’s Football Is Knee-Centred and Match-Dominated: A Prospective One-Season Cohort Study
Reference: J Clin Med. 2026 Jun 29;15(13):5059. doi: 10.3390/jcm15135059.
Authors: Niklas Engel, Markus Geßlein, Maximilian Willauschus et al.
Download link: https://www.mdpi.com/2077-0383/15/13/5059
Summary: Injury epidemiology in women’s football has primarily focused on elite athletes, whereas the amateur level, representing the vast majority of female players worldwide, remains largely under-explored. We aimed to provide a first prospective one-season characterisation of injuries in German amateur women’s football. In this prospective observational cohort study, 26 clubs comprising 450 female amateur players in Bavaria were monitored over the 2023/24 season using standardised time-loss injury questionnaires as used in current professional registry studies. Injuries were characterised by anatomical location, type, mechanism, and activity context (match vs. training); proportions are reported with 95% binomial exact confidence intervals (CI). A total of 68 injuries were recorded. Regarding injuries with documented information, 66.7% (95% CI 54.0-77.8) were acute traumatic and 78.2% (95% CI 65.0-88.2) occurred during matches. Lower-extremity injuries dominated (80.3%; 95% CI 71.2-90.5), led by the knee as the single most frequent region (28.2%; 95% CI 18.1-40.1). Ligament injuries were the most common injury type (27.9%). Seven ACL ruptures were documented (10.3%; 95% CI 4.2-20.1), all of which occurred during match play. Indirect-contact mechanisms were significantly over-represented among all knee injuries (OR 6.92, 95% CI 1.52-31.6; p = 0.012). Amateur injury profile in this study reproduced the knee-centred, match-dominated pattern of elite female football while carrying a relative ACL burden at the upper end of professional reference data; given the small number of ACL events (n = 7), this signal is hypothesis-generating. These findings support the extension of structured neuromuscular prevention programmes into German amateur women’s football.
#32 Associations between internal training load and changes in sprint endurance and aerobic fitness during a 4 – week off-season HIIT program in adolescent female football players
Reference: Sci Rep. 2026 Jul 11. doi: 10.1038/s41598-026-61983-9. Online ahead of print.
Authors: Marco Panascì, Gennaro Apollaro, Vittoria Ferrando et al.
Download link: https://www.nature.com/articles/s41598-026-61983-9_reference.pdf
Summary: This single-group observational study investigated, in female football players, the associations between internal training load (ITL) metrics and changes in sprint endurance and aerobic fitness following a 4-week off-season training program combining small-sided games (SSGs) and repeated-sprint training (RST). Fifteen adolescent female football players (age: 14.9 ± 1.6 years) completed two SSG and two RST sessions per week, for a total of 16 sessions. Sprint endurance was assessed by the 30-s all-out test (30-s test), while aerobic fitness was evaluated using the Yo-Yo Intermittent Recovery Test Level 1 (YYIR1), both administered pre- and post-intervention. ITL was quantified using heart rate-derived measures, including time spent at ≥ 90% of peak heart rate (T ≥ 90%HRpeak), training impulse (TRIMP), and session rating of perceived exertion training load (sRPE-TL). Significant changes were observed in both sprint endurance (30-s test: p = 0.004, d = 1.88) and aerobic fitness (YYIR1: p < 0.001, d = 1.21). Weekly TRIMP and T ≥ 90%HRpeak showed significant increases throughout the intervention period (p < 0.01), whereas sRPE-TL remained relatively stable. Correlation analyses revealed significant associations (p ≤ 0.008) between ITL metrics and performance changes: sRPE-TL was correlated with changes in the YYIR1 (ρ = 0.94), TRIMP with the 30-s test (ρ = 0.66), and T ≥ 90%HRpeak with the 30-s test (r = 0.87) and YYIR1 (r = 0.67). These findings suggest that, in adolescent female football players, ITL metrics, particularly T ≥ 90%HRpeak, are associated with changes in sprint endurance and aerobic fitness during a short-term, HIIT off-season program. Moreover, sRPE-TL and TRIMP may provide practical indicators for monitoring individual training responses in short off-season periods. However, our findings should be interpreted with caution due to the absence of a control group.