Footballscience.net
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 Impact of match-related contextual variables on weekly training load in a professional soccer team: a full season study
Reference: Biol Sport. 2022 Jan;39(1):125-134. doi: 10.5114/biolsport.2021.102927. Epub 2021 Mar 7.
Authors: Jose M Oliva Lozano, Vincenzo Rago, Víctor Fortes, José M Muyor
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8805347/pdf/JBS-39-102927.pdf
Summary: The purpose of this study was to analyse the impact of match-related contextual variables (match location, match outcome and level of the opponent) on the weekly training load in a professional soccer team throughout a full competitive season. Total distance, high-speed running distance (HSRD, > 18 km·h-1), highmetabolic load distance (HMLD, > 25.5 W·kg-1), player load and total number of impacts (above 3 G) were collected from training and match sessions in professional soccer players (n = 25) competing in LaLiga123. Comparisons of external load parameters by each match-related contextual variable were examined using a mixed-effect model. Differences between playing positions were found for total distance (p < 0.05; r = 0.11-0.15), HSRD (p < 0.05; r = 0.13-0.19), HMLD (p < 0.05; r = 0.12-0.19), player load (p < 0.05; r = 0.11-0.19) and impacts (p < 0.05; r = 0.15-0.26). However, no significant interaction was observed between match-related contextual variables and playing position for any variable (p > 0.05). In addition, a significant impact of match outcome (p < 0.05; r = 0.11-0.15), opponent level (p < 0.05; r = 0.11-0.17) and match location (p < 0.05; r = 0.14-0.20) on the weekly training load (before and after the match) was observed. In conclusion, match-related contextual variables seem to slightly affect weekly external training load. Thus, coaching and medical departments could consider the influence of these contextual variables when prescribing the training load relative to the match demands.
#2 Recovery following the extra-time period of soccer: practitioner perspectives and applied practices
Reference: Biol Sport. 2022 Jan;39(1):171-179. doi: 10.5114/biolsport.2022.104066. Epub 2021 Mar 11.
Authors: Adam Field, Liam David Corr, Chris James Thompson, Jean Carlos Gonzalez Lucena, Hugo Sarmento, Robert Joseph Naughton, Thomas Edward Brownlee, Matthew Haines, Richard Michael Page, Liam David Harper
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8805349/pdf/JBS-39-104066.pdf
Summary: Research has demonstrated that the extra-time (ET) period of soccer negatively impacts recovery. However, it is not known to what extent recovery practices are being adapted by practitioners following ET and where gaps exist between research and practice. Therefore, this study explored soccer practitioner perceptions of recovery practices following ET matches. A total of 72 practitioners from across different levels of soccer and several countries completed a bespoke online survey. Inductive content analysis of the responses identified five higher-order themes: 'conditioning', 'player monitoring', 'recovery practices', 'training', and 'future research directions'. Mixed responses were received in relation to whether practitioners condition players in preparation for ET, though 72% allowed players to return to training based on fatigue markers following this additional 30-min period. Sixty-three (88%) practitioners believed that ET delays the time-course of recovery, with 82% highlighting that practices should be adapted following ET compared with a typical 90-min match. Forty-nine practitioners (68%) reduce training loads and intensities for up to 48 hr post ET matches, though training mostly recommences as 'normal' at 72 hr. Sixty-three (88%) practitioners believed that more research should be conducted on recovery following ET, with 'tracking players physiological and physical responses', 'nutritional interventions to accelerate recovery' and 'changes in acute injury-risk' being the three areas of research that practitioners ranked as most important. These data suggest practitioners and coaches adjust recovery practices following ET matches compared to 90 min. Further research on the efficacy of recovery strategies following ET matches is required to inform applied practice.
#3 DNN-based multi-output model for predicting soccer team tactics
Reference: PeerJ Comput Sci. 2022 Jan 20;8:e853. doi: 10.7717/peerj-cs.853. eCollection 2022.
Authors: Geon Ju Lee, Jason J Jung
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8802790/pdf/peerj-cs-08-853.pdf
Summary: In modern sports, strategy and tactics are important in determining the game outcome. However, many coaches still base their game tactics on experience and intuition. The aim of this study is to predict tactics such as formations, game styles, and game outcome based on soccer dataset. In this paper, we propose to use Deep Neural Networks (DNN) based on Multi-Layer Perceptron (MLP) and feature engineering to predict the soccer tactics of teams. Previous works adopt simple machine learning techniques, such as Support Vector Machine (SVM) and decision tree, to analyze soccer dataset. However, these often have limitations in predicting tactics using soccer dataset. In this study, we use feature selection, clustering techniques for the segmented positions and Multi-Output model for Soccer (MOS) based on DNN, wide inputs and residual connections. Feature selection selects important features among features of soccer player dataset. Each position is segmented by applying clustering to the selected features. The segmented positions and game appearance dataset are used as training dataset for the proposed model. Our model predicts the core of soccer tactics: formation, game style and game outcome. And, we use wide inputs and embedding layers to learn sparse, specific rules of soccer dataset, and use residual connections to learn additional information. MLP layers help the model to generalize features of soccer dataset. Experimental results demonstrate the superiority of the proposed model, which obtain significant improvements comparing to baseline models.
#4 The Role of Crowd Support on Home Advantage during COVID-19 Restrictions on Italian Football Competitions. Comparison between 2018-19 and 2020-21 Seasons of the Italian Serie A and Serie B Championships
Reference: Sports (Basel). 2022 Jan 30;10(2):17. doi: 10.3390/sports10020017.
Authors: Matteo Vandoni, Ottavia E Ferraro, Alessandro Gatti, Luca Marin, Matteo Giuriato, Dario Silvestri, Nicola Lovecchio, Mariangela V Puci, Vittoria Carnevale Pellino
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8878181/pdf/sports-10-00017.pdf
Summary: The home advantage (HA) affects football competitions, especially due to the presence of crowd support. Even though several studies demonstrated that HA (which is influenced by the crowd) decreased in recent years, the empty stadia caused by COVID-19 restrictions offered unique situations to explore and quantify HA. For this reason, we aimed to assess HA in two seasons of the major Italian Championships. We conducted an observational study with the data from the last three seasons of the Italian football championship A-B series, analyzing a total of 2.964 individual game scores. To quantify the HA, the number of points won at home was calculated as a percentage of the total number of points won, home and away. In every season and for every team classification, HA was found (scored points > 50% in home matches). We reported a difference in HA median score for Serie B. Additionally, a difference was found in Serie A for middle-ranking HA median scores in the two seasons compared (p-value = 0.017), which was similarly found in Serie B (p-value = 0.009). The number of penalties was lower in the season with a crowd compared to one without a crowd (p = 0.001). The HA did not disappear in empty stadiums, so there must be other contributing factors. Additionally, we found that the referees were biased by the presence of the crowd in favor of the home teams, and this result could be considered by the football association during referees' training and formation.
#5 Assessing Omega-3 Intake in Sport: Brief Food Frequency Questionnaire is Associated with Omega-3 Index in Collegiate Women Soccer Players
Reference: J Athl Train. 2022 Feb 23. doi: 10.4085/1062-6050-0549.21. Online ahead of print.
Authors: Macy Essman, Danielle Christifano, Debra K Sullivan, Prabhakar Chalise, Aaron Carbuhn
Summary: Omega-3 fatty acids modulate inflammatory processes and are considered beneficial for sport populations highlighting a need to practically assess omega-3 intake. Food frequency questionnaires (FFQ) are inexpensive, non-invasive, tools aimed to evaluate nutrient intakes like omega-3 fatty acids. A tailored, brief FFQ for estimating omega-3 intake has been previously reported in healthy adults to be associated with erythrocyte omega-3 fatty acid levels, a biomarker for omega-3 tissue status and indicative of intake. However, the association between a brief omega-3 FFQ with respective erythrocyte levels, particularly Omega-3 Index has yet to be explored in a sport population. The aim was to examine the association between omega-3 intake using a brief FFQ and Omega-3 Index (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and EPA+DHA) in collegiate women soccer players. Thirty-one NCAA Division I collegiate women soccer players participated in this study. The brief omega-3 FFQ assessed dietary omega-3 intake: DHA, EPA. OmegaQuant blood test measured erythrocyte omega-3 fatty acids (EPA, DHA) and Omega-3 Index (EPA+DHA) levels. Brief FFQ intake of EPA, DHA, and EPA+DHA were positively correlated with erythrocyte EPA (r = 0.48, p = 0.007), DHA (r = 0.73, p < 0.001), and Omega-3 Index (r = 0.73, p < 0.001). In a sample of collegiate women soccer players, the brief omega-3 FFQ is correlated with erythrocyte omega-3 fatty acid levels and may be a practical tool for health practitioners in assessing omega-3 intake within this collegiate sport population.
#6 Relationships of Final Velocity at 30-15 Intermittent Fitness Test and Anaerobic Speed Reserve with Body Composition, Sprinting, Change-of-Direction and Vertical Jumping Performances: A Cross-Sectional Study in Youth Soccer Players
Reference: Biology (Basel). 2022 Jan 27;11(2):197. doi: 10.3390/biology11020197.
Authors: Ana Filipa Silva, Sumer Alvurdu, Zeki Akyildiz, Filipe Manuel Clemente
Download link: https://www.mdpi.com/2079-7737/11/2/197/htm
Summary: This study aimed to determine the relationships of locomotor profile (combination of a player's maximal oxygen uptake and running economy)-measured by the final velocity attained at 30-15 Intermittent Fitness Test (VIFT) and the anaerobic speed reserve (ASR)-with the body composition, countermovement jump (CMJ), sprinting performances, and change-of-direction (COD) ability of youth soccer players. A cross-sectional study design was implemented. A total of 124 youth soccer players from different age groups (15, 16, 17, 18, and 19 years old) were voluntarily recruited. ASR was determined based on the difference between maximal sprint speed (MSS) and VIFT. Players were tested for the following measures: (i) body composition (body mass and body fat percentage); (ii) CMJ (height of jump); (iii) sprinting time measured at 5, 10, 15, 20, 25, and 30 m; (iv) MSS measured in the best split time (5 m) over the 30 m test; (v) COD ability (time, asymmetry index); and (vi) final velocity at 30-15 IFT (VIFT). A Pearson product-moment correlation test was used to examine the relationships. Height and body mass exhibited large correlations with VIFT (r = 0.835 and r = 0.699, respectively) and small correlations with ASR (r = 0.177 and r = 0.256, respectively). The CMJ was largely correlated with VIFT (r = 0.631 to r = 0.650) while presenting small correlations with ASR (r = 0.227 to r = 0.232). Both VIFT and ASR had moderate (r = 0.3 to r = 0.5) correlations with sprinting time at different distances and very large correlations with MSS (r = 0.797 to r = 0.866). The COD time was largely correlated with VIFT (r = 0.765 and r = 0.775) while exhibiting small-to-moderate correlations with ASR (r = -0.279 and r = -0.301). In conclusion, it was found that locomotor performance at 30-15 VIFT presents high levels of correlation with anthropometry and physical fitness; ASR also presents correlations with these variables, but they are smaller. This suggest that ASR is an independent variable that should be considered for inclusion in information for characterizing players' capacities.
#7 Mental health problems and risk assessment in football players infected with SARS-CoV-2: a cross-sectional study
Reference: J Sports Med Phys Fitness. 2022 Feb 21. doi: 10.23736/S0022-4707.22.13493-6. Online ahead of print.
Authors: Yavuz Lima, Nevzad Denerel, Sergen Devran, Mehmet G Günver, Bülent Bayraktar, Simon Rice
Summary: Although the negative psychological impact of the pandemic on athletes is well known, there is currently insufficient evidence regarding mental health (MH) problems among athletes infected with SARS-CoV-2. The aim of the present study was to evaluate the association between MH problems, demographics, and SARSCoV-2 related variables in football players infected with SARS-CoV-2. An online survey included demographic questions, SARS-CoV-2 related questions, the Athlete Psychological Strain Questionnaire, and the Depression Anxiety Stress Scales-21 was distributed to male and female professional football players aged between 18-38 and infected with SARS CoV-2. A total of 261 football players participated in the study. The odds of athlete-specific distress in lowerlevel football players were up to 5.9 times more than those competing at the highest level (OR=3.06-5.93, 95% CI=1.27-14.43, p<0.01). The odds of depression and stress in lower-level football players were up to 6.7 times more than those competing at the highest level (both OR=3.70-6.77, 95% CI=1.18-19.20, p<0.01). In players who reported sleep problems, there was increased risk of athlete-specific distress (OR=2.43, 95% CI=1.31-4.52, p<0.01), depression (OR=3.71, 95% CI=1.98-6.95, p<0.01), anxiety (OR=2.93, 95% CI=1.62-5.28, p<0.01), and stress (OR=.7,08 95% CI=3.52-14.02, p<0.01). There was increased risk of depression and stress in female players (OR=5.78, 95% CI=2.03-16.4, p<0.01; OR=4.91, 95% CI=1.57-15.4, p<0.01; respectively). The odds of anxiety in players who reported severe SARS-C0V-2 symptoms were up to 2.2 times more than asymptomatic players (OR=2.28, 95% CI=1.08-4.82, p=0.03). MH problems in football players infected with SARS-CoV-2 were associated with female gender, participation in football in the lower-level, performance concerns, and sleep problems. MH assessment is indicated in athletes infected with SARS-CoV-2 to support detection, and appropriate and timely intervention.
#8 Most amateur football teams do not implement essential components of neuromuscular training to prevent anterior cruciate ligament injuries and lateral ankle sprains
Reference: Knee Surg Sports Traumatol Arthrosc. 2022 Feb 21. doi: 10.1007/s00167-022-06878-8.
Authors: Nikki Rommers, Roland Rössler, Bruno Tassignon, Jo Verschueren, Roel De Ridder, Nicky van Melick, Lieselot Longé, Tim Hendrikx, Peter Vaes, David Beckwée, Christophe Eechaute
Download link: https://link.springer.com/content/pdf/10.1007/s00167-022-06878-8.pdf
Summary: Neuromuscular training (NMT) is effective at reducing football injuries. The purpose of this study was to document the use of NMT to prevent anterior cruciate ligament injuries and lateral ankle sprains in adult amateur football and to identify barriers for using NMT. A preseason and in-season online survey was completed by players and coaches of 164 football teams. The survey contained questions concerning injury history, type and frequency of NMT, and barriers when NMT was not used. A total of 2013 players (40% female) and 180 coaches (10% female) completed the preseason survey, whereas 1253 players and 140 coaches completed the in-season survey. Thirty-four percent (preseason) to 21% (in-season) of players used NMT, but only 8% (preseason) to 5% (in-season) performed adequate NMT (i.e. both balance and plyometric exercises, at least twice per week). In the subpopulation of players with an injury history, 12% (preseason) and 7% (in-season) performed adequate NMT. With respect to the coaches, only 5% (preseason) and 2% (in-season) implemented adequate NMT. Most important barriers for using NMT for both players and coaches were a lack of belief in its effectiveness, a lack of knowledge, the belief that stretching is sufficient, and not feeling the need for it. Most amateur football teams do not implement essential components of NMT. The results highlight the urgent need for developing strategies to enhance the adequate use of NMT in amateur football.
#9 Influence of the Weekly and Match-play Load on Muscle Injury in Professional Football Players
Reference: Int J Sports Med. 2022 Feb 21. doi: 10.1055/a-1533-2110. Online ahead of print.
Authors: Víctor Moreno-Perez, Miguel Angel Campos-Vazquez, Javier Toscano, Victor Javier Sotos-Martinez, Roberto López-Del Campo, Ricardo Resta, Juan Del Coso
Summary: The aim of this investigation was to examine the impact of the weekly training load and the match running patterns prior to a muscle injury as potential risk factors of muscle injury in professional football players. Forty male professional football players participated in the investigation. Running distances at different intensities 5 min and 15 min prior to the injury were compared to the same time-points in official matches of the same player with no injury events. Furthermore, the cummulative session rating of perceived exertion (sRPE) and training load of the week prior to the injury were compared to a control week (mean value of training weeks without injury). Nineteen players suffered 31 non-contact muscle injuries during matches. The distance covered at 21-24 km/h (p<0.001; effect size (ES)=0.62) and at>24 km/h (p=0.004; ES=0.51) over the 5-min period prior to the injury was greater than in matches without injury. The cumulative sRPE (p=0.014; ES=1.33) and training volume (p=0.002; ES=2.45) in the week prior to the injury was higher than in a control week. The current data suggest that the combination of a training week with a high load and a short period of high intensity running during the match might increase the risk of muscle injury in professional footballers.
#10 Lower Limb Injuries in an English Professional Football Club: Injury Analysis and Recommendations for Prevention
Reference: Phys Sportsmed. 2022 Feb 22. doi: 10.1080/00913847.2022.2045176. Online ahead of print.
Authors: Mohamad Y Fares, Katy Stewart, Michael McBride, John Maclean
Summary: Lower limb injuries constitute a problem in the sport of football. Our aim is to explore patterns and trends of lower limb injuries in an English professional football club. This is a descriptive epidemiological study. Reports provided by the club's physical therapy team were screened for injuries among professional football players sustained over four seasons, from 2015/2016 to 2018/2019. Data included setting of injury (in-match or training), anatomical location of injury, type of injury, number of days off and month of injury. A total of 296 lower limb injuries were recorded in our study, with a rate of 11.14 per 1000 football hours. Injury rate during games was 51.38 per 1000 football hours, significantly greater than that during training at 3.81 per 1000 football hours (p=0.021). The thigh was significantly the most commonly injured location at 4.67 per 1000 football hours (p<0.001). Grade I tears were the most common injury type at 1.73 per 1000 football hours, significantly greater than grade III tears (p=0.027), contusions (p=0.043), fractures (p=0.02), and lacerations (p=0.019). Injury rates were found to be greatest during preseason and declined as season progressed. On average, an injury sidelined the affected footballer for a total of 20 days. Lower limb injuries were more common during matches than training. The thigh is the most common injury location, and grade I muscle tear was the most common type of injury. Injury rates were higher early on in the season. Potential prevention strategies include spacing out competition, adopting training and exercise regimens that cater for recovery, and increasing research regarding injury mechanisms.
#11 A video-based analysis of situations bearing the risk of respiratory disease transmission during football matches
Reference: Sci Rep. 2022 Feb 22;12(1):3034. doi: 10.1038/s41598-022-07121-7.
Authors: Oliver Faude, Simon Müller, Sebastian Schreiber, Jonas Müller, Lukas Nebiker, Florian Beaudouin, Tim Meyer, Florian Egger
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8863802/pdf/41598_2022_Article_7121.pdf
Summary: We aimed to analyze the number and type of contacts involving the risk of respiratory disease transmission during football match play. We analysed 50 matches from different playing levels. Two reviewers evaluated the contacts of all players in each match. We focused on between-player contacts, crowding, actions with potentially increased aerosol and droplet production and within-player hand-to-head contacts. We categorized the duels with direct contact into frontal and other ones and measured contact duration. The number of between-player contacts were similar between playing levels (median 28.3 [IQR 22.6, 33] contacts per player-hour). Frontal contacts summed up to 8% of all contacts. Contacts involving the head occurred less than once per player and match with none lasting longer than 3 s. Crowding included between two and six players and the duration was mostly less than 10 s. Aerosol and droplet producing activities were three to four times more frequent in adult compared to youth players. Our results suggest that the risk of respiratory pathogen transmission is low during football matches. This conclusion is based on the finding that most close contact situations are of short duration and on the fact that it is an outdoor sport.
#12 The effects of individual and collective variability on youth players' movement behaviours during football small-sided games
Reference: Res Sports Med. 2022 Feb 24;1-16. doi: 10.1080/15438627.2022.2042293. Online ahead of print.
Authors: Diogo Coutinho, Bruno Gonçalves, Sara Santos, Bruno Travassos, Wolfgang Schöllhorn, Jaime Sampaio
Summary: This study aimed to identify the effects of playing with additional individual (IND), collective (COL) or individual-collective (MIX) variability on youth football players' performance during small-sided games. Twelve youth football players (U17, age = 16.1 ± 0.9 years) played a goalkeeper (Gk) + 6 outfield players a-side (Gk+6vs6+Gk) under four conditions: (i) playing in the 1:2:3:1 formation without any other rule (control condition, CTR); (ii) 1:2:3:1 formation with additional body restrictions changing each minute (individual condition, IND); (iii) using different tactical formations modified each minute (collective condition, COL; (iv) using different tactical formations and body restrictions varied each minute (individual-collective condition, MIX). Generally, there were similar behaviours across conditions, especially for the CTR and the MIX. Nevertheless, the CTR condition presented moderate higher values in the lateral direction (p ≤ .05), while also higher longitudinal synchronization compared to the IND (p ≤ .05). The COL condition presented higher spatial exploration (p ≤ .05), which may justify the higher values for distance covered while running and sprinting (p ≤ .05). Overall, coaches may use the IND condition to refine players' technical actions, while the COL condition to develop players' ability to perform in different playing positions and team structures.
#13 Postmatch Recovery Practices Carried Out in Professional Football: A Survey of 56 Portuguese Professional Football Teams
Reference: Int J Sports Physiol Perform. 2022 Feb 24;1-7. doi: 10.1123/ijspp.2021-0343. Online ahead of print.
Authors: Sérgio M Querido, João Brito, Pedro Figueiredo, Filomena Carnide, João R Vaz, Sandro R Freitas
Summary: In football (ie, soccer), the effectiveness of recovery practices is critical to maintain high levels of performance, prevent residual fatigue, and reduce injury risk. However, the recovery methods that professional football teams put in place up to 72 hours postmatch are widely unknown. This study aimed to characterize the postmatch recovery practices in Portuguese football teams in different postmatch periods and match locations. Portuguese football teams (total, N = 56; male: first league [n = 17], second league [n = 16], under-23 league [n = 12]; female: first league, n = 11) participated in the study. The practitioners in charge of recovery strategies in each team filled out the online questionnaire in the middle of the 2019-20 season. The questions focused on the type of recovery methods to be used at different times after home and away matches. After home matches, stretching, electrostimulation, active recovery, and massage were used with higher frequency (P < .017) in later postmatch periods (ie, 12-24, and 24-72 h) compared with immediately postmatch. After away matches, several differences were found (P < .017) for the stretching, electrostimulation, active recovery, cold-water immersion, massage, nutrition, and sleep between postmatch periods. Regarding match location, stretching (r = .19), active recovery (r = .39), cold-water immersion (r = .46), and massage (r = .29) showed a higher frequency of use immediately after home matches. Conversely, the use of compression garments (r = .27) was higher immediately after away matches. It was concluded that in professional football, recovery methods are not applied uniformly along postmatch periods and differ depending on the match location.
#14 Predictors of selection into an elite level youth football academy: A longitudinal study
Reference: J Sports Sci. 2022 Feb 25;1-16. doi: 10.1080/02640414.2022.2044128. Online ahead of print.
Authors: Daniel Fortin-Guichard, Inge Huberts, Jurrit Sanders, Ruud van Elk, David L Mann, Geert J P Savelsbergh
Summary: Talent identification in football is complex. Research regarding talent indicators that predict selection into professional academies is increasingly multi-disciplinary, though is typically cross-sectional, failing to consider whether the rate of change of those indicators influences selection. The aim of this study was to determine if longitudinal changes in talent indicators are associated with selection into a professional football academy. A total of 110 Dutch male football players (aged 8-12) playing in a youth development programme of a professional club were included in the study. Players were assessed regularly on their anthropometry, physical fitness, gross motor coordination, technical ability, and psychosocial capacities over four years. A subset of players was then selected into the academy. Cross-sectional and longitudinal analyses revealed the indicators that best predicted selection. The best indicator was the 30 m sprint speed, with prediction not improving when including other predictors or their rate of change. The individuals that the club ultimately selected at age 12 could have been predicted well above chance levels using the sprint speeds at age nine or ten. The relative consistency of the rate of improvement in indicators across participants meant that the rate at which they developed played little role in selections.
#15 Semi-quantitative magnetic resonance imaging scoring of the knee detects previous injuries in professional soccer players
Reference: Knee Surg Sports Traumatol Arthrosc. 2022 Feb 19. doi: 10.1007/s00167-022-06897-5.
Authors: Goetz Hannes Welsch, Anna-Maria Behr, Karl-Heinz Frosch, Enver Tahir, Milena Pachowsky, Frank Oliver Henes, Gerhard Adam, Kai-Jonathan Maas, Malte Lennart Warncke
Download link: https://link.springer.com/content/pdf/10.1007/s00167-022-06897-5.pdf
Summary: The medical examination ("medical") is an important procedure in professional soccer since it has high economic relevance. In addition to clinical tests, magnetic resonance imaging (MRI) is used to assess joint health. In the present study, the reliability of semiquantitative knee MRI during the "medical" in professional soccer was tested, and its relationship with clinical data and days missed due to knee injury was observed. In this cross-sectional study, between 2012 and 2019, 69 newly assigned players (age 18-35 years) from a professional soccer club underwent MRI (3.0 T) of both knee joints during their "medical". Reported knee injuries and previously missed days due to injury were obtained from player anamnesis and the "transfermarkt.com" database. Based on the established "Whole-Organ Magnetic Resonance Imaging Score" (WORMS), two independent radiologists graded the MRI results. Further evaluation was based on the mean score of both knees. The mean WORMS for all subjects was 13.9 (median 10.5, range 0-61). Players with previous injuries had significantly higher scores than players without reported injuries (22.1 ± 17.7 vs. 8.9 ± 4.4, p < 0.002). Three outliers (previously undetected injuries) in the group of players without reported injuries were observed (6.7%). The WORMS was significantly correlated with a prior knee injury (r: 0.424, p < 0.0001) and days missed due to injury (r: 0.489, p < 0.001). Age was correlated with the WORMS (r: 0.386, p < 0.001). In a linear regression model, prior injury was the only significant predictor of a high WORMS (p = 0.001). The WORMS was a significant predictor of days missed due to injury (p < 0.0002) and prior injury (sensitivity: 78%, specificity: 91%, p = 0.006). The intraclass correlation coefficient was excellent (0.89). Semiquantitative knee MRI for WORMS determination during the soccer "medical" is a robust and reliable method. Prior injury, even in players without documented trauma, was detected by the WORMS, and previously missed days due to injury were correlated with the semiquantitative MR knee score.
#16 Age-Related Electrocardiographic Characteristics of Male Junior Soccer Athletes
Reference: Front Cardiovasc Med. 2022 Feb 3;8:784170. doi: 10.3389/fcvm.2021.784170. eCollection 2021.
Authors: Elena Cavarretta, Luigi Sciarra, Giuseppe Biondi-Zoccai, Francesco Maffessanti, Antonia Nigro, Fabio Sperandii, Emanuele Guerra, Federico Quaranta, Chiara Fossati, Mariangela Peruzzi, Annachiara Pingitore, Dimitrios M Stasinopoulos, Robert A Rigby, Rachele Adorisio, Andrea Saglietto, Leonardo Calò, Giacomo Frati, Fabio Pigozzi
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8850359/pdf/fcvm-08-784170.pdf
Summary: Very limited data exist on normal age-related ECG variations in adolescents and no data have been published regarding the ECG anomalies induced by intensive training, which are relevant in pre-participation screening for sudden cardiac death prevention in the adolescent athletic population. The purpose of this study was to establish normal age-related electrocardiographic measurements (P wave duration, PR interval, QRS duration, QT, and QTc interval) grouped according to 2-year age intervals. A total of 2,151 consecutive healthy adolescent Soccer athletes (trained for a mean of 7.2 ± 1.1 h per week, 100% male Caucasians, mean age 12.4 ± 1.4 years, range 7-18) underwent pre-participation screening, which included ECG and transthoracic echocardiography in a single referral center. Their heart rate progressively slowed as age increased (p < 0.001, ranging from 80.8 ± 13.2 to 59.5 ± 10.2 bpm), as expected. The P wave, PR interval, and QRS duration significantly increased in older age classes (p = 0.019, p = 0.001, and p < 0.001, respectively), and after Bonferroni's correction, the difference remained significant in all age classes for QRS duration. The QTc interval diminished progressively with increasing age (p = 0.003) while the QT interval increased progressively (p < 0.001). Significant variations in the normal ECG characteristics of young athletes exist between different age groups related to increasing age and training burden, thus, age-specific reference values could be adopted, as already done for echocardiographic measurements, and may help to further discriminate potentially pathologic conditions.
#17 The effects of repeated sprint training with vs. without change of direction on measures of physical fitness in youth male soccer players
Reference: J Sports Med Phys Fitness. 2022 Feb 21. doi: 10.23736/S0022-4707.22.13521-8. Online ahead of print.
Authors: Yassine Negra, Senda Sammoud, Rodrigo Ramirez-Campillo, Raja Bouguezzi, Jason Morán, Helmi Chaabene
Summary: Fitness characteristics such as linear sprinting, repeated sprint ability, and change of direction (CoD) are important for male youth soccer players to maximize training safety and physical performance. We aimed to compare the effects of a 9-week repeated sprint training (RST) program, with and without change of direction (CoD) movements, on repeated sprint ability (RSA total time [RSAtotal], RSA best time [RSAbest]), CoD speed (505 CoD test), linear sprint speed (10-m and 20-m linear sprint), and aerobic endurance (AE; Yo-Yo intermittent endurance test level 1) in male youth soccer players. During the in-season period, 20 soccer players were randomly assigned to a RST with CoD (RSTCoD) group (n = 10, age = 15.4±0.4 years) or a repeated linear sprint training group (n = 10, age = 15.6±0.3 years). Both training groups completed approximately two 15 minutes RST sessions per week, with the only difference between training programmes being the inclusion of one CoD movement during sprint repetitions for the RSTCoD group. The two-way ANOVA with repeated measures revealed a significant, moderate effect of time for RSAbest and RSAtotal (effect size [d] = 0.69 and 0.67, respectively). Likewise, significant, moderate-to-large effects of time were found for CoD (d=0.83), 10-m and 20-m sprint (d=0.68 and 0.67, respectively), and AE (d=0.66). No significant group × time interactions were observed for any measure of physical fitness (d=0.00 to 0.16). RST with and without CoD movements is equally effective in improving RSA total and best time, CoD speed, linear sprint speed, and AE in youth male soccer players.
#18 The effects of repeated sprint training with vs. without change of direction on measures of physical fitness in youth male soccer players
Reference: J Sports Med Phys Fitness. 2022 Feb 21. doi: 10.23736/S0022-4707.22.13521-8. Online ahead of print.
Authors: Yassine Negra, Senda Sammoud, Rodrigo Ramirez-Campillo, Raja Bouguezzi, Jason Morán, Helmi Chaabene
Summary: Fitness characteristics such as linear sprinting, repeated sprint ability, and change of direction (CoD) are important for male youth soccer players to maximize training safety and physical performance. We aimed to compare the effects of a 9-week repeated sprint training (RST) program, with and without change of direction (CoD) movements, on repeated sprint ability (RSA total time [RSAtotal], RSA best time [RSAbest]), CoD speed (505 CoD test), linear sprint speed (10-m and 20-m linear sprint), and aerobic endurance (AE; Yo-Yo intermittent endurance test level 1) in male youth soccer players. During the in-season period, 20 soccer players were randomly assigned to a RST with CoD (RSTCoD) group (n = 10, age = 15.4±0.4 years) or a repeated linear sprint training group (n = 10, age = 15.6±0.3 years). Both training groups completed approximately two 15 minutes RST sessions per week, with the only difference between training programmes being the inclusion of one CoD movement during sprint repetitions for the RSTCoD group. The two-way ANOVA with repeated measures revealed a significant, moderate effect of time for RSAbest and RSAtotal (effect size [d] = 0.69 and 0.67, respectively). Likewise, significant, moderate-to-large effects of time were found for CoD (d=0.83), 10-m and 20-m sprint (d=0.68 and 0.67, respectively), and AE (d=0.66). No significant group × time interactions were observed for any measure of physical fitness (d=0.00 to 0.16). RST with and without CoD movements is equally effective in improving RSA total and best time, CoD speed, linear sprint speed, and AE in youth male soccer players.
#19 Coaches' Criteria for Talent Identification of Youth Male Soccer Players
Reference: Sports (Basel). 2022 Jan 18;10(2):14. doi: 10.3390/sports10020014.
Authors: Jan Fuhre, Arild Øygard, Stig Arve Sæther
Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8875243/pdf/sports-10-00014.pdf
Summary: The main aim of this study was to examine which criteria coaches considered in the talent identification of youth male soccer players aged 13-16. The second aim was to describe how the coaches considered these criteria when identifying players for their club or regional teams and how these criteria take the impact of the relative age effect into consideration. We conducted qualitative, semi-structured interviews with six male coaches from a professional club academy or a regional team within the Norwegian Football Federation. In line with earlier research, the results showed that the coaches considered the technical, tactical, and mental factors as the most important in talent identification. Further in line with earlier research, they considered that the physiological and sociological factors were of secondary importance, while anthropometric measures were considered the least important. Regarding the relative age effect, the coaches were aware of the effect and its consequences, while few of them had ways to reduce the effect and its impact on their talent identification process. Even so, the coaches highlighted the importance of considering a holistic approach to talent identification. The results show similarities with earlier research, but there is still a need for more longitudinal studies that investigate criteria for talent identification in youth football.
#20 The Effects of Proprioceptive Training on Balance, Strength, Agility and Dribbling in Adolescent Male Soccer Players
Reference: Int J Environ Res Public Health. 2022 Feb 11;19(4):2028. doi: 10.3390/ijerph19042028.
Authors: Diana Victoria Gidu, Dana Badau, Marius Stoica, Adrian Aron, George Focan, Dan Monea, Alina Mihaela Stoica, Nicoleta Daniela Calota
Download link: https://www.mdpi.com/1660-4601/19/4/2028/htm
Summary: The aim of the study was to determine the effects of proprioceptive training (PT) on balance, strength, agility and dribbling in adolescent soccer players. In this research, we included an experimental (n = 48) and a control (n = 48) group (CG) with 14 years old players. The experimental group (EG) participated in an 8 week PT program, with four 30 min sessions per week. The experimental program included 12 bosu ball exercises to improve balance, stability and strength which were grouped into two subprograms: the first not using the soccer ball, the second subprogram using the soccer ball. The subprograms were implemented alternately during 16 proprioceptive training sessions, on two types of firm and foam surfaces. Pre- and post-tests included the static balance [Balance Error Scoring System (BESS)], vertical, horizontal, and lateral jumping, and the completion of agility ("arrowhead") and dribbling ("short dribbling") tests. Regarding the total BESS score, the CG has demonstrated progress between the pre- and the post-test, with 0.780 ± 0.895, fewer errors, while the EG had 5.828 ± 1.017 fewer errors. The difference between the two groups was of 5.148 fewer errors for the EG who had practiced the proposed program of proprioceptive training. The highest difference registered between the pre- and the post-test was at the test "single-leg forward jump with the right leg", with a result of 1.083 ± 0.459 cm for the CG and of 3.916 ± 0. 761 cm for the EG. Through the analysis of average differences between the pre- and the post-tests, we observe that, regarding the "Agility right side test", the EG has progressed with 0.382 s in comparison with the CG; regarding the "Agility left side test", the EG has progressed with 0.233 s compared to the CG; regarding the "Agility right and left side test", the EG has progressed with 0.196 s compared to the CG; in the "Short dribbling test", the EG has progressed with 0.174 s compared to the CG. The highest progress was made at the "Agility right side test", of 0.402 s for the EG, while the CG registered 0.120 s. Most of the results in all tests for both experimental groups show an effect size ranging from small to medium. The progress made by the experimental group in all tests was statistically significant, while in the control group the progress was mostly statistically insignificant for p < 0.05. The results suggest that a PT program performed at about 14 years of age could be successfully implemented in the training regime of soccer players to improve components of fitness along with dribbling skills. The results of the study revealed that sports training on the foam surfaces determined a superior progress of the development of proprioception compared to the increased training on the firm surfaces.
