Latest research in football - week 48 - 2023

#1 Aluminum Concentrations in Male and Female Football Players during the Season

Reference: Toxics. 2023 Nov 10;11(11):920. doi: 10.3390/toxics11110920.

Authors: María C Robles-Gil, Víctor Toro-Román, Marcos Maynar-Mariño, Jesús Siquier-Coll, Ignacio Bartolomé, Francisco J Grijota

Summary: Aluminum (Al) is one of the most abundant trace mineral elements in the earth's crust. Al is considered a potent neurotoxicant. Physical exercise could cause modifications in some trace mineral elements. On the other hand, there could be sex differences in the exposure and deposits of toxic mineral elements. The aim of the present study was to compare sex and seasonal differences in extracellular and intracellular Al concentrations in football players. The study involved 22 male and 24 female football players from the fifth and second national category, respectively. Three assessments were carried out during the season (beginning, middle and end). Al concentrations in plasma, urine, erythrocytes and platelets were determined. Male football players ingested more Al (p < 0.05). Higher plasma Al concentrations were reported in male football players (p < 0.01). On the other hand, in both groups, increases and decreases in Al in the plasma and urine were observed in the second and third assessment, respectively (p < 0.01). There were sex differences in platelet Al concentrations (p < 0.05). Plasma and platelet Al concentrations may be different between the sexes. Al concentrations may change over the course of a season in football players.

 

 

#2 Distinguishing skill from technique in football

Reference: Sci Med Footb. 2023 Nov 24. doi: 10.1080/24733938.2023.2288138. Online ahead of print.

Authors: Kyle J M Bennett, Job Fransen

Summary: The current commentary adopts a skill acquisition science perspective on the distinction between skill and technique, two constructs often confused in football science and practice. It first positions technique as a coordination pattern. It then argues that experts rarely (if ever) coordinate their neuromuscular system in the same way through evidence of inter- and intra-individual movement variability from football science and other domains of sport science. It concludes by asserting that skill distinguishes itself from technique by its requirement for functional and beneficial coordination patterns, meaning that coaches, sporting practitioners and researchers should consider skill as any technique that an athlete successfully applies to a situation that requires it.

 

 

#3 Long-Term Bovine Colostrum Supplementation in Football Players

Reference: Nutrients. 2023 Nov 14;15(22):4779. doi: 10.3390/nu15224779.

Authors: Mirosława Cieślicka, Błażej Stankiewicz, Radosław Muszkieta, Małgorzata Tafil-Klawe, Jacek Klawe, Anna Skarpańska-Stejnborn, Joanna Ostapiuk-Karolczuk

Summary: Physical exercise, especially of high intensity, is a significant burden on an athlete's body. It should be emphasized that achieving high results in competitive sports requires the use of significant, sometimes extreme, exercise loads during training, which may result in homeostasis disorders, adversely affecting the fitness of athletes. This study aims to investigate the effects of 6 months of bovine colostrum supplementation on indicators of immune system functioning, selected parameters related to iron management, and anabolic/catabolic balance in young football players. Twenty-eight male football players completed a double-blind, placebo-controlled crossover protocol (24 weeks of colostrum/placebo). A standardized exercise test was executed at the beginning of the trial and after 3 and 6 months of supplementation. Blood samples were taken before and after the exercise test and after 3 h of recovery. Markers of iron homeostasis, pro- and anti-inflammatory balance, and hormonal responses were determined. A significant increase in immunoglobulin G concentration was observed, accompanied by a decrease in inflammatory markers in supplemented athletes. Bovine colostrum supplementation had no significant effect on athletes' performance or on iron management and hormonal response. The use of bovine colostrum, which is characterized by a high content of immunologically active compounds, can be an element of a relatively mild and safe intervention for reducing inflammation induced by intense physical exercise.

 

 

#4 Performance Analysis of the Spanish Men's Top and Second Professional Football Division Teams during Eight Consecutive Seasons

Reference: Sensors (Basel). 2023 Nov 11;23(22):9115. doi: 10.3390/s23229115.

Authors: Ibai Errekagorri, Roberto López Del Campo, Ricardo Resta, Julen Castellano

Download link: https://www.mdpi.com/1424-8220/23/22/9115

Summary: The present study aimed to analyse the performance of the Spanish men's top (LaLiga1) and second (LaLiga2) professional football division teams for eight consecutive seasons (from 2011-2012 to 2018-2019). The variables recorded were Passes, Successful Passes, Crosses, Shots, Goals, Corners, Fouls, Width, Length, Height, distance from the goalkeeper to the nearest defender (GkDef) and total distance covered (TD). The main results were that (1) LaLiga1 teams showed lower values of Length from 2013-2014, and lower values of GkDef and TD from 2014-2015; (2) LaLiga2 teams showed fewer Passes and lower values of GkDef and TD from 2014-2015, and fewer Goals and lower values of Length from 2015-2016; and (3) LaLiga1 teams showed more Passes, Successful Passes, Shots and Goals and higher values of TD compared to LaLiga2 teams during the eight-season period. This study concludes that LaLiga1 teams showed fewer final offensive actions, LaLiga2 teams showed fewer Passes and Goals and the teams of both leagues played in a space with greater density (meters by player), covering less distance as the seasons passed. The information provided in this study makes it possible to have reference values that have characterised the performance of the teams.

 

 

#5 Imaging of muscle injuries in soccer

Reference: Skeletal Radiol. 2023 Nov 22. doi: 10.1007/s00256-023-04514-1. Online ahead of print.

Authors: Rafael Heiss, Johannes L Tol, Tobias Pogarell, Frank W Roemer, Guus Reurink, Jerome Renoux, Michel D Crema, Ali Guermazi

Summary: Accurate diagnosis of muscle injuries is a challenge in everyday clinical practice and may have profound impact on the recovery and return-to-play decisions of professional athletes particularly in soccer. Imaging techniques such as ultrasound and magnetic resonance imaging (MRI), in addition to the medical history and clinical examination, make a significant contribution to the timely structural assessment of muscle injuries. The severity of a muscle injury determined by imaging findings has a decisive influence on therapy planning and affects prognosis. Imaging is of high importance when the diagnosis or grade of injury is unclear, when recovery is taking longer than expected, and when interventional or surgical management may be needed. This narrative review will discuss ultrasound and MRI for the assessment of sports-related muscle injuries in the context of soccer, including advanced imaging techniques, with the focus on the clinical relevance of imaging findings for the prediction of return to play.

 

 

#6 A 5-year follow-up of Achilles tendon reconstruction using a full-thickness graft processed with the clearant method and retrograde fixation in the calcaneus: a case study of an amateur soccer player

Reference: J Exp Orthop. 2023 Nov 22;10(1):119. doi: 10.1186/s40634-023-00690-0.

Authors: Luis Alberto Buendia Saavedra

Download link: https://jeo-esska.springeropen.com/counter/pdf/10.1186/s40634-023-00690-0.pdf

Summary: We present a case of a 41-year-old male amateur soccer player with no comorbidities, who experienced a rerupture of the Achilles tendon 5 years after his initial end-to-end plasty. To address this, we opted for a full-thickness reconstruction using a graft under the Clearant Process of the Achilles tendon. As an innovative approach, we proposed an alternative fixation technique, employing a Bio Composite Arthrex 9 mm x 35 mm interference screw, placed at the apex of the calcaneus body. For a period of 5 years, the patient underwent regular imaging follow-ups with Magnetic Resonance Imaging (MRI) and clinical assessments using the Foot and Ankle Ability Measure Activity Subscale Score and Foot and Ankle Ability Measure Sports Subscale Score. This case highlights the importance of exploring novel fixation methods for Achilles tendon reconstruction, particularly in cases of rerupture. The use of the Bio Composite Arthrex screw, in conjunction with the Clearant Process graft, demonstrated promising results both in imaging and functional outcomes, but more case studies with positive results are needed to evaluate the effectiveness of this reconstruction.

 

 

#7 An investigation into the effect of audiences on the soccer penalty kick

Reference: Sci Med Footb. 2023 Nov 23. doi: 10.1080/24733938.2023.2285963. Online ahead of print.

Authors: Ran Zheng, John van der Kamp, Kjeld Kemperman, Iris de Jong, Simone Caso

Summary: The effects of audiences in boosting the performance of the home team (i.e. home advantage) in sports like soccer have been studied extensively. However, much less attention has been paid to how audiences influence the performance of individual team members. To this end, the current study compared in-game penalty kicks taken by home and away teams in eight major European leagues with audiences in the 2018-2019 season to kicks taken without audiences in the 2020-2021 season during the COVID-19 pandemic. No unequivocal evidence for home or away team advantage with respect to penalty outcome (i.e. goal, no goal) was revealed. Yet, results did show that the number of missed penalties of home teams (i.e. penalties kicked at or outside the frame of the goal) significantly reduced when no audience was present. This supports the hypothesis that home audiences increase anxiety of penalty takers and thus the likelihood of choking. However, the reduced number of missed penalties did not significantly increase penalty outcome of home teams when playing without audiences, suggesting additional, unidentified effects of audiences, possibly also including opponent goalkeepers. Finally, when no audience was present, away teams demonstrated significantly poorer penalty outcome. Future research investigating the effects of audiences on the penalty kick should consider more detailed performance measures of both penalty takers and goalkeepers.

 

 

#8 Effects of the New COVID-19-Induced Rule on Substitutions and Performance in Italian Elite Soccer

Reference: Sports (Basel). 2023 Oct 26;11(11):208. doi: 10.3390/sports11110208.

Authors: Bruno Ruscello, Matteo Tozzi, Gennaro Apollaro, Alberto Grossi, Gabriele Morganti, Mario Esposito, Laura Pantanella, Giuseppe Messina, Elvira Padua

Summary: COVID-19 has resulted in widespread changes, including within the realm of sports. Professional soccer has adapted by allowing more substitutions, leading to tactical adjustments and potential physical benefits. Accordingly, this study analyzed the impact of the new rule in Italian top-level soccer, focusing on substitution patterns and performance differences between the pre-COVID (2017-2018, 2018-2019 seasons) and post COVID (2020-2021, 2021-2022 seasons) eras. As such, publicly available data from 1520 matches (760 matches per era) were recorded. The sample included matches played from 40 Italian top division teams in both the pre- and post-COVID eras. Analyses confirmed substitutions follow a consistent temporal pattern throughout the match in both eras, highlighting a slight difference in second-half management, and showed the new rule is still not used to its full potential, thus raising concerns about teams' financial strength, as not all managers possess "deep benches" (i.e., a large number of top-level players available to play). Further analyses revealed a statistically significant increment (p = 0.002) in the quantity of collectively produced sprints in the post-COVID era compared to the pre-COVID one. The results from this study emphasize the need to carefully address sprint preparation and repeated sprint abilities, also considering factors such as the number of substitutes and their skill level.

 

 

#9 Leg and Joint Stiffness of the Supporting Leg during Side-Foot Kicking in Soccer Players with Chronic Ankle Instability

Reference: Sports (Basel). 2023 Nov 7;11(11):218. doi: 10.3390/sports11110218.

Authors: Akihiro Tamura, Keita Shimura, Yuri Inoue

Summary: Soccer players with chronic ankle instability (CAI) may stabilize their supporting leg by the proximal joint to compensate for the ankle instability during kicking motion. This study aimed to investigate the characteristics of leg and joint stiffness of the supporting leg during side-foot kicking in soccer players with CAI. Twenty-four male collegiate-level soccer players with and without CAI participated in this study. The kinematic and kinetic data were obtained using a three-dimensional motion analysis system. Leg stiffness and joint (hip, knee, and ankle) stiffness in the sagittal and frontal planes were calculated and analyzed. The results clarified that soccer players with CAI (0.106 ± 0.053 Nm/°) had greater knee stiffness in knee adduction during the kicking cycle compared to those without CAI (0.066 ± 0.030 Nm/°; p = 0.046), whereas no characteristic differences were observed in knee stiffness in knee flexion and hip and ankle stiffness (p > 0.05). Knee stiffness is believed to occur to compensate for ankle joint instability in the supporting leg. Therefore, adjusting knee stiffness to accommodate ankle joint instability is crucial for maintaining kicking performance. Based on results of this study, it may be important to consider training and exercises focused on joint coordination to improve knee stiffness in soccer players with CAI.

 

 

#10 The Influence of Somatic Maturity on Anthropometrics and Body Composition in Youth Soccer Players

Reference: Children (Basel). 2023 Oct 26;10(11):1732. doi: 10.3390/children10111732.

Authors: Pavlína Kalčíková, Miroslava Přidalová 

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7664635/pdf/ijerph-17-08247.pdf

Summary: The primary aim of this investigation was to compare players' anthropometric (AP) and body composition (BC) characteristics between distinct maturity bands (pre-PHV, circa-PHV, post-PHV) in youth elite soccer. This study considered 320 male soccer players (mean age 13.8 y). Participants were from U14 (n = 157) and U15 (n = 163) age categories. The Khamis-Roche method was applied to calculate the percentage of predicted adult height (PAH) at the time of assessment based on which the players were further divided into maturity bands (pre-PHV ≤ 87%, circa-PHV = 88-95%, post-PHV > 95%). The findings indicated that most of the players were in the circa-PHV stage at the time of investigation. Measurements included height and weight. The estimates of BC parameters were derived using bioelectrical impedance (BIA) analysis. These various AP and BC attributes displayed significant differences among the maturity bands (F = 139.344-7.925; p < 0.001; large effect sizes) except in body fat mass (BFM) (F = 2.998; p = 0.051; small effect size). The current somatic maturity stage of the athletes should be considered when evaluating BC results, otherwise there is a risk of misinterpretation.

 

 

#11 Does the Video Assistant Referee (VAR) mitigate referee bias on professional football?

Reference: PLoS One. 2023 Nov 27;18(11):e0294507. doi: 10.1371/journal.pone.0294507. eCollection 2023.

Authors: Thadeu Gasparetto, Kirill Loktionov

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10681297/pdf/pone.0294507.pdf

Summary: The purpose of the paper is to check whether the introduction of the VAR system mitigated the referee bias against away teams. The dataset comprises 2279 matches played in the first tier of the Brazilian League from 2016 to 2021. We analyze 6 seasons of the first tier of the Brazilian domestic football league- 3 seasons before and 3 seasons after the introduction of the VAR technology. Potential bias is viewed through the lens of yellow cards, red cards and number of penalties awarded for both home and away clubs. A paired t-test is used to reveal potential statistical differences between pre-VAR and post-VAR periods, followed by Ordinary Least Squares regressions to inspect whether certain referee' categories have changed their behavior after the implementation of this technology. Our empirical findings offer evidence that the referee bias is diminished, but still present.

 

 

#12 Gambling, cryptocurrency, and financial trading app marketing in English Premier League football: A frequency analysis of in-game logos

Reference: J Behav Addict. 2023 Nov 27. doi: 10.1556/2006.2023.00066. Online ahead of print.

Authors: Jamie Torrance, Conor Heath, Maira Andrade, Philip Newall

Download link: https://akjournals.com/view/journals/2006/aop/article-10.1556-2006.2023.00066/article-10.1556-2006.2023.00066.xml?body=pdf-26836

Summary: The gamblification of UK football has resulted in a proliferation of in-game marketing associated with gambling and gambling-like products such as cryptocurrencies and financial trading apps. The English Premier League (EPL) has in response banned gambling logos on shirt-fronts from 2026 onward. This ban does not affect other types of marketing for gambling (e.g., sleeves and pitch-side hoardings), nor gambling-like products. This study therefore aimed to assess the ban's implied overall reduction of different types of marketing exposure. We performed a frequency analysis of logos associated with gambling, cryptocurrency, and financial trading across 10 broadcasts from the 2022/23 EPL season. For each relevant logo, we coded: the marketed product, associated brand, number of individual logos, logo location, logo duration, and whether harm-reduction content was present. There were 20,941 relevant logos across the 10 broadcasts, of which 13,427 (64.1%) were for gambling only, 2,236 (10.7%) were for both gambling and cryptocurrency, 2,014 (9.6%) were for cryptocurrency only, 2,068 (9.9%) were for both cryptocurrency and financial trading, and 1,196 (5.7%) were for financial trading only. There were 1,075 shirt-front gambling-associated logos, representing 6.9% of all gambling-associated logos, and 5.1% of all logos combined. Pitch-side hoardings were the most frequent marketing location (52.3%), and 3.4% of logos contained harm-reduction content. Brand logos associated with gambling, cryptocurrency, and financial trading are common within EPL broadcasts. Approximately 1 in 20 gambling and gambling-like logos are subject to the EPL's voluntary ban on shirt-front gambling sponsorship.

 

 

#13 Simultaneous Talocalcaneal and Talonavicular Joint Dislocation With Navicular Bone Fracture of a Teenager While Playing Football: A Report of a Rare Case

Reference: Cureus. 2023 Oct 28;15(10):e47848. doi: 10.7759/cureus.47848. eCollection 2023 Oct.

Authors: Mahmut Gorkem Gurcinar, Muhammed Yusuf Afacan, Sinan Ustundag, Fecri Ciftlik

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10679841/pdf/cureus-0015-00000047848.pdf

Summary: Simultaneous talocalcaneal and talonavicular joint dislocation, in other words, subtalar joint dislocation, and navicular bone lateral process fracture are rare orthopedic injuries. In this case, we aimed to discuss the effectiveness and ergonomics of non-surgical follow-up with a short leg splint after reduction of talonavicular, talocalcaneal joint dislocation, and lateral process fracture of the navicular bone. A 17-year-old male patient was admitted to the emergency department with swelling and pain in his left foot after spraining his left foot while playing football. Pain, swelling, and deformity in the left foot were evident without a neurovascular deficit. Radiographs showed simultaneous left foot talonavicular joint dislocation, talocalcaneal joint dislocation, and navicular lateral process fracture. The patient underwent closed reduction and a short leg splint. We followed the patient regularly, removed the leg splint in the fourth week, and started various movement exercises. We started muscle strengthening exercises in the sixth week and reached full range of motion with full muscle strength without any deformity in the eighth week. In this case, closed reduction and short leg splint with traction along the axis of the left foot and manipulation of the talus laterally by everting the ankle were sufficient. We restricted the movement of the ankle and tarsometatarsal joint with a short leg splint and reached full range of motion with follow-ups and exercises.

 

 

#14 Changes in head staff members in male elite-level football teams are associated with increased hamstring injury burden for that season: the UEFA Elite Club Injury Study

Reference: BMJ Open Sport Exerc Med. 2023 Nov 15;9(4):e001640. doi: 10.1136/bmjsem-2023-001640. eCollection 2023.

Authors: Jan Ekstrand, Wart Van Zoest, Håkan Gauffin

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10660205/pdf/bmjsem-2023-001640.pdf

Summary: The aim was to evaluate whether a change of head coach or other head staff before or during a season is correlated to hamstring injury (HI) burden in male elite-level football (soccer) in Europe. The survey was conducted using a questionnaire reporting any staff change within the team. Data about the head staff changes and hamstring injury burdens were collected from 14 teams participating in the Elite Club Injury Study (ECIS) during the 2019/2020, 2020/2021 and 2021/2022 seasons. On average, replacing the head coach before or during a season happens in every second season. All changes, except for the change of the head coach during a season, indicate an association with an increase in HI burden (ranging from 10% to 81%). However, only changes in the fitness coach and team doctor roles reached statistical significance. The HI burden seems to be influenced by adding new staff members, such as the head of fitness/performance coach in 36% of the teams and the team doctor in 17%. New head coaches starting the season with their own, for the team new, fitness/performance coach was highly associated with increased HI burden (p<0.001). Bringing their own fitness/performance coaches is common for managers entering a new elite male football club. However, this paper has highlighted that this trend seems to lead to a three times increase in HI burden. Similarly, replacing the team doctor was also associated with increased HI burden. Instability among head staff members in male elite-level football teams seems associated with increased HI burden during the season.