Latest research in football - week 47 - 2023

#1 Are We Jumping to the Wrong Conclusions? Longer Jumps and More Hops in Female Football Players Who Went on to Sustain a Primary or Secondary ACL Injury Compared to Those Who Did Not

Reference: Sports Med Open. 2023 Nov 10;9(1):105. doi: 10.1186/s40798-023-00656-7.

Authors: Anne Fältström, Joanna Kvist, Martin Hägglund

Download link: https://sportsmedicine-open.springeropen.com/counter/pdf/10.1186/s40798-023-00656-7.pdf

Summary: Different functional performance tests are used to assess patients in the clinic and before return to sport (RTS), where the rehabilitation goal is to reach good strength and jumping ability. A limb symmetry index of ≥ 90% is a common target in rehabilitation before RTS. The aim of this short communication is to use data from our 2-year prospective cohort study on female football players, either with or without an anterior cruciate ligament (ACL) reconstruction, to discuss whether hop performance in 3 commonly used hop tests can inform safe football participation, that is, with a low risk for ACL injury or reinjury. At baseline, 117 active female football players (mean age ± standard deviation, 20 ± 2 years) were included 19 ± 9 months after ACL reconstruction as well as 119 matched female knee-healthy players (age 19 ± 3 years). All players performed a single hop for distance test, 5-jump test and side hop test at baseline and were then prospectively followed for 2 years. Twenty-eight (24%) players sustained a second ACL injury and 8 (7%) sustained a primary ACL injury. Longer jumps in the 5-jump test (922 cm vs. 865 cm, Cohen's d = - 0.60) and more hops in the side hop test for both limbs (41-42 hops vs. 33-36 hops, d = - 0.43 to - 0.60) were seen in players who sustained a second ACL injury compared with those who did not. Longer jumps in the single hop for distance test (both limbs) (139-140 cm vs. 124-125 cm, d = - 0.38 to - 0.44), in the 5-jump test (975 cm vs. 903 cm, d = -0.42) and more hops in the side hop test (both limbs) (48-49 hops vs. 37-38 hops, d = - 0.38 to - 0.47) were seen in players who sustained a primary ACL injury compared with those who did not. The average hop performance, i.e. longer jumps or more hops, was greater in players who went on to sustain a primary or secondary ACL injury compared to those who did not over a two-year follow-up period. Even though hop tests are not used in isolation to evaluate readiness to RTS, their interpretation needs consideration in the decision-making process of returning to pivoting sports.

 

 

 

#2 'More than likely the men come first. That's just very frustrating'. A qualitative exploration of contextual factors affecting the implementation of injury prevention initiatives and the provision of effective injury management in elite-level women's club football in Ireland

Reference: Br J Sports Med. 2023 Nov 9:bjsports-2022-106548. doi: 10.1136/bjsports-2022-106548.

Authors: Dan Horan, Eamonn Delahunt, Mark Roe, Martin Hägglund, Catherine Blake, Seamus Kelly

Summary: The aim of our study was to explore the contextual factors that affect the implementation of football injury prevention initiatives and the provision of effective injury management in the Irish Women's National League (WNL). We used a criterion-based purposive sampling approach to recruit coaches (n=7), players (n=17) and medical personnel (n=8) representing eight of the nine clubs in the WNL to participate in one-to-one semistructured interviews. Our study was located within an interpretivist, constructivist research paradigm. The interview data were analysed using reflexive thematic analysis. The participants identified academic and work pressures, financial challenges, conflict with college football, inadequate facilities and gender inequity as being barriers to the implementation of injury prevention initiatives and the provision of effective injury management. Financial constraints within clubs were perceived to limit the provision of medical care and strength and conditioning (S&C) support and this was deemed to be associated with a heightened risk of injuries. Specific contextual factors were identified which curtail the implementation of injury prevention initiatives and the provision of effective injury management in elite-level women's club football in Ireland. Gender inequity was identified as one of the factors impacting the availability of high-quality medical care, S&C support, as well as access to training and match facilities. Our results provide new insights that could be used to inform the design and implementation of injury prevention and management initiatives for women football players in Ireland.

 

 

#3 Generations, events, and social movement legacies: Unpacking social change in English football (1980-2023)

Reference: Br J Sociol. 2023 Nov 10.  doi: 10.1111/1468-4446.13065. Online ahead of print.

Authors: Mark Turner, Jan Andre Lee Ludvigsen

Download link: https://onlinelibrary.wiley.com/doi/epdf/10.1111/1468-4446.13065

Summary: This article critically employs the case of association football in England, from 1980 to 2023, as a social movement timescape, to examine the political consciousness and long-term mobilisations of a generation of football supporter activists, and their capacity to influence politics, and respond to new, emerging, critical junctures, through networks of trust and shared memories of historical events. This is of crucial importance to sociology because it reveals the tensions between what are considered legitimate and illegitimate social practices which characterise contemporary society's moral economy. Focusing on temporal contestations over regulation, policing, governance and cultural rituals, the article deconstructs the role of generations in social movements, and critically synthesises relational-temporal sociology and classic and contemporary work on the sociology of generations, to show how legacy operates as a multifaceted maturing concept of power and time. In English football's neoliberal timescape, the supporters' movement has reached a critical juncture; the future will require a new generation of activists, to negotiate, resist and contest the new hegemonic politics of social control and supporter engagement.

 

 

#4 Relationships Between Task Constraints, Visual Constraints, Joint Coordination and Football-Specific Performance in Talented Youth Athletes: An Ecological Dynamics Approach

Reference: Percept Mot Skills. 2023 Nov 10:315125231213124. doi: 10.1177/00315125231213124.

Authors: Pieter Heuvelmans, Stefano Di Paolo, Anne Benjaminse, Laura Bragonzoni, Alli Gokeler

Download link: https://journals.sagepub.com/doi/epub/10.1177/00315125231213124

Summary: Individual performance in team sports is a multifactorial reflection of how well a player can cope and accomplish tasks in varied playing situations. Thus, performance analysis should not only focus on outcomes, but also on underlying mechanisms of those outcomes. We adopted principles of the ecological dynamics approach (EDA) to investigate the effect of introducing constraints on players' joint coordination responses for a football-specific performance drill outcome. Seventeen talented youth football (soccer) players performed a football-specific drill under different conditions: basic constraints, additional defender dummies, stroboscopic glasses, and a combination of the latter two constraints. We recorded these players' execution time, passing accuracy, and lower extremity joint kinematics. We calculated joint coordination for hip-knee, knee-ankle, and trunk-hip couplings. The added constraints negatively affected execution time and passing accuracy, and caused changes in joint coordination. Furthermore, we identified a relationship between execution time and joint coordination. This study serves as an example how the EDA can be adopted to investigate mechanisms that underlie individual performance in team sports.

 

 

#5 Prediction of ACL-tear by lower limbs muscle strength and flexibility: a prospective cohort study in 95 female soccer players

Reference: Res Sports Med. 2023 Nov 15:1-23. doi: 10.1080/15438627.2023.2280554. Online ahead of print.

Authors: Antonio Cejudo, José Manuel Armada-Zarco, Francisco Ayala, Pilar Sainz de Baranda

Summary: The aims of the study were to build models using logistic regression analysis of flexibility and strength tests to prospectively predict risk factors for anterior cruciate ligament tear (ACL-tear) in female soccer (FS) players, and to determine training cut-off for risk factors of the predictive model built. A prospective cohort study of 95 female players (aged 14-33 years) was conducted. Age, anthropometric data, soccer history, lower limb range of motion (ROM) and hip maximal isometric strength (MIS) were measured. At the prospective follow-up after 12 months, 7.4% of the players had developed an ACL-tear. The model showed a significant relationship (χ2(93) = 30.531, p < 0.001) between the ACL-tear and the predictor variables (leg length, HAD-NH [hip adduction] MIS, asymmetric ROM [ankle dorsiflexion with knee extended (AD-KE) and with knee flexed (AD-KF), and HE (hip extension)], hip ROM [HIR (internal rotation) and HAB (abduction)]). The Akaike Information Criteria (AIC) and Bayesian Information Criteria (BIC) for model fit were 30.24 and 51.79, respectively. The value R2 showed good model fit, 76.5% for Nagelkerke´s R2, 71.4% for McFadden´s R2 and 67.5% for Tjur´s R2. For the screening test, cut-off for leg length of ≥0.40 m, for HIR ROM of ≤44º and for asymmetry of HE ROM of ≥5° were set, which have an acceptable (AUC ≥ 0.755) discriminatory ability for the development of ACL-tear.

 

 

#6 Determinants of Performance in Professional Soccer Players at 2 and 5 Years After ACL Reconstruction

Reference: Am J Sports Med. 2023 Nov 13:3635465231207832. doi: 10.1177/03635465231207832.

Authors: Vítor Hugo Pinheiro, Kyle A Borque, Mitzi S Laughlin, Mary Jones, Ganesh Balendra, Madison R Kent, Ryan Ajgaonkar, Andy Williams

Summary: A number of studies have investigated return to play after anterior cruciate ligament reconstruction (ACLR) in professional soccer players, but it is unclear which factors are associated with a return to the preinjury performance and ability to play over time. The purpose was to identify factors that contribute to a professional soccer player's return to preinjury performance after ACLR, as well as to report their playing performance at 2 and 5 years after ACLR compared with their preinjury performance. A consecutive cohort of professional soccer players undergoing primary ACLR were analyzed between 2005 and 2019. A minimum 2-year follow-up was required. The effect of patient, surgical, and postoperative factors on performance rates, defined as a combination of league level and playing time, was evaluated with univariate and multivariate logistic regression models. A total of 200 male professional soccer players were included. When combining league level and playing time, 30% of athletes returned to their preinjury performance at 2 years and 22% at 5 years. However, 53% of athletes returned to their preinjury performance for at least 1 season by year 5. At 2 years, a chondral lesion of grade 3 or 4 decreased the odds of return to preinjury performance (odds ratio [OR], 0.37; P = .010). Athletes receiving an ACLR with the addition of a lateral extra-articular tenodesis procedure were 2.42 times more likely to return to preinjury performance at 2 years than athletes with ACLR alone (P = .004). By 5 years after ACLR, athletes aged ≥25 years at the time of reconstruction were 3 times less likely to be performing at their preinjury performance (OR, 0.32; P < .001), and those with a grade ≥3 chondral lesion were >2 times less likely to be performing at their preinjury performance (OR, 0.43; P = .033). The presence of >50% thickness chondral pathology, ACLR without lateral extra-articular tenodesis, and age >25 years at the time of surgery were all significant risk factors of worse performance rates after ACLR. Significant decreases in performance rates were noted at 2 and 5 years postoperatively.

 

 

#7 Adaptation of YOLOv7 and YOLOv7_tiny for Soccer-Ball Multi-Detection with DeepSORT for Tracking by Semi-Supervised System

Reference: Sensors (Basel). 2023 Oct 25;23(21):8693. doi: 10.3390/s23218693.

Authors: Jorge Armando Vicente-Martínez, Moisés Márquez-Olivera, Abraham García-Aliaga, Viridiana Hernández-Herrera

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10650813/pdf/sensors-23-08693.pdf

Summary: Object recognition and tracking have long been a challenge, drawing considerable attention from analysts and researchers, particularly in the realm of sports, where it plays a pivotal role in refining trajectory analysis. This study introduces a different approach, advancing the detection and tracking of soccer balls through the implementation of a semi-supervised network. Leveraging the YOLOv7 convolutional neural network, and incorporating the focal loss function, the proposed framework achieves a remarkable 95% accuracy in ball detection. This strategy outperforms previous methodologies researched in the bibliography. The integration of focal loss brings a distinctive edge to the model, improving the detection challenge for soccer balls on different fields. This pivotal modification, in tandem with the utilization of the YOLOv7 architecture, results in a marked improvement in accuracy. Following the attainment of this result, the implementation of DeepSORT enriches the study by enabling precise trajectory tracking. In the comparative analysis between versions, the efficacy of this approach is underscored, demonstrating its superiority over conventional methods with default loss function. In the Materials and Methods section, a meticulously curated dataset of soccer balls is assembled. Combining images sourced from freely available digital media with additional images from training sessions and amateur matches taken by ourselves, the dataset contains a total of 6331 images. This diverse dataset enables comprehensive testing, providing a solid foundation for evaluating the model's performance under varying conditions, which is divided by 5731 images for supervised system and the last 600 images for semi-supervised. The results are striking, with an accuracy increase to 95% with the focal loss function. The visual representations of real-world scenarios underscore the model's proficiency in both detection and classification tasks, further affirming its effectiveness, the impact, and the innovative approach. In the discussion, the hardware specifications employed are also touched on, any encountered errors are highlighted, and promising avenues for future research are outlined.

 

 

#8 Under-Fuelling for the Work Required? Assessment of Dietary Practices and Physical Loading of Adolescent Female Soccer Players during an Intensive International Training and Game Schedule

Reference: Nutrients. 2023 Oct 24;15(21):4508. doi: 10.3390/nu15214508.

Authors: Samuel J McHaffie, Carl Langan-Evans, Juliette A Strauss, José L Areta, Christopher Rosimus, Martin Evans, Ruth Waghorn, James P Morton

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10649861/pdf/nutrients-15-04508.pdf

Summary: Previous studies demonstrate that "under-fuelling" (i.e., reduced carbohydrate (CHO) and energy intake (EI) in relation to recommended guidelines) is prevalent within adult female soccer players, the consequence of which may have acute performance and chronic health implications. However, the dietary practices of adolescent female soccer players, a population who may be particularly at risk for the negative aspects of low energy availability (LEA), are not well documented. Accordingly, we aimed to quantify EI and CHO intake, physical loading and estimated energy availability (EA) in elite national team adolescent female soccer players (n = twenty-three; age, 17.9 ± 0.5 years) during a 10-day training and game schedule comprising two match days on day six (MDa) and nine (MDb). The players self-reported their EI via the remote food photography method, whilst the physical loading and associated exercise energy expenditure were assessed via GPS technology. The relative CHO intake was significantly greater (all p < 0.05) on the day before the first match (MD-1a) (4.1 ± 0.8 g·kg-1), on the day before the second match (MD-1b) (4.3 ± 1.1 g·kg-1), MDa (4.8 ± 1.2 g·kg-1) and MDb (4.8 ± 1.4 g·kg-1) in comparison to most other days (<4 g·kg-1). The mean daily measured EA over the 10-day period was 34 ± 12 kcal·kg FFM-1·day-1 (with six players, i.e., 34%, presenting LEA), though, when adjusting the energy intake for potential under-reporting, these values changed substantially (44 ± 14 kcal·kg FFM-1·day-1, only one player was classed as presenting LEA). Such data suggest that the prevalence of LEA amongst female team sport athletes may be over-estimated. Nonetheless, players are still likely under-fuelling for the work required in relation to the daily CHO recommendations (i.e., >6 g·kg-1) for intensive training and game schedules. These data provide further evidence for the requirement to create and deliver targeted player and stakeholder education and behaviour change interventions (especially for younger athletes) that aim to promote increased daily CHO intake in female soccer players.

 

 

#9 Rehabilitation of Soccer Players' Knee Injuries: Cartilage Reconstruction, Anterior Cruciate Ligament Surgery, and Intensive Recovery-A Pilot Study

Reference: J Clin Med. 2023 Nov 1;12(21):6893. doi: 10.3390/jcm12216893.

Authors: Bartłomiej Kacprzak, Karolina Rosińska

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10650160/pdf/jcm-12-06893.pdf

Summary: Knee injuries, particularly anterior cruciate ligament (ACL) damage and cartilage defects, are highly prevalent among athletes and affect their sports performance and long-term joint function. The purpose of this research was to evaluate the effectiveness of a comprehensive combination therapy approach for individuals with ACL and cartilage injuries. Twelve professional soccer players aged 18 to 30 years underwent bone-tendon-bone ACL reconstruction, microfracture cartilage repair surgery, and hyaluronic acid scaffold treatment. Early postoperative rehabilitation included immediate supervised physiotherapy and complete weight bearing. Follow-up assessments involved clinical evaluations, functional joint assessments, and magnetic resonance imaging (MRI) scans to measure cartilage defect repair and symptom alleviation. The results showed that patients resumed pain-free activities within 3-4 weeks and returned to their pre-injury level within 4.5 months. MRI demonstrated the absence of inflammatory reactions, repair of marrow edema, and the emergence of new cartilage. Six months and one year after surgery, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Short Form (36) Health Survey (SF-36) questionnaire results demonstrated considerable improvement in patients' health condition and quality of life. Overall, the study suggests that the combination of Hyalofast membranes, microfracture surgery, tissue adhesive, and intensive postoperative physical therapy may be a potential alternative to commonly used treatments for patients with ACL rupture, allowing them to recover efficiently and return to sports activities.

 

 

#10 Normative data on horizontal power, acceleration, and change-of-direction ability in amateur youth female soccer players

Reference: J Sports Med Phys Fitness. 2023 Nov 13. doi: 10.23736/S0022-4707.23.15426-0. Online ahead of print.

Authors: William H Suits, Meg A Darmofal, Ryan A Bean

Summary: Physical performance measures such as horizontal power, acceleration, and change-of-direction ability are related to performance in soccer, and may aid in talent selection, coaching decisions and the prescription of training programs. The purpose of this study was to describe the normative values of three performance tests in amateur female youth soccer players. A cross-sectional descriptive study design was employed with 151 amateur female youth soccer players (age 14.20±1.13 years). Physical performance measures included the standing broad jump, 10-meter sprint, and Pro-Agility Test. Time since peak height velocity (PHV) was calculated to represent physical maturity status. Descriptive statistics were sought, and Pearson's correlation coefficients were used to identify correlations between variables. One-Way Analysis of Variance with a Tukey post-hoc test was used to calculate the relationship between categorical groups of chronological ages and years since PHV. Significance was set at P<0.05. Normative data for each physical performance measure are presented based on chronological age and physical maturity status for amateur female youth soccer players. Chronological age was significantly associated with improved performance in standing broad jump (R=0.558; 95% CI: 0.436, 0.658; P<0.01), 10-meter sprint time (R=-0.375; 95% CI: -0.495, -0.217; P<0.01), and Pro-Agility Test time (R=-0.424; 95% CI: -0.546, -0.284; P<0.01). Physical maturity status was also significantly associated with improved performance in standing broad jump (R=0.650; 95% CI: 0.426, 0.711; P<0.01), 10-meter sprint time (R=-0.430; 95% CI: -0.507, -0.232; P<0.01), and Pro-Agility Test time (R=-0.453; 95% CI: -0.554, -0.293; P<0.01). The normative data from this study demonstrates differences in physical performances across chronological ages and physical maturity status. Physical maturity status had a slightly stronger association for all performance measures than chronological age. The variance and range tended to increase across performance measures with increasing age.

 

 

#11 Reliability and validity of a reactive agility test with soccer goalkeeper-specific movements for adolescents

Reference: J Sports Med Phys Fitness. 2023 Nov 13. doi: 10.23736/S0022-4707.23.15048-1. Online ahead of print.

Authors: Yosuke Abe, Masao Nakayama, Noriteru Morita

Summary: There is a lack of objective measures and assessments of goalkeeping proficiency and performance in the literature. Furthermore, no reports have focused on adolescent goalkeepers (under the age of 15). The aim of this study was to determine the reliability and validity of the Goalkeeper Reactive Agility Test for Adolescents (GRATA). Content validity was assessed by seven experts and the Item-Content Validity Index (I-CVI) was calculated. We used similar settings to an agility test for college-aged goalkeepers, although the number of repetitions and running direction of the latter parts of the test were modified (number of repetitions: from 3 to 2; running direction: from forward to backward). Eighty-five adolescent male goalkeepers (age: 13.4 years) performed the test three times. The intraclass correlation coefficient (ICC) was used for relative reliability and the standard error of measurement (SEM) and the smallest worthwhile change (SWC) for absolute reliability. The I-CVI was 0.86, above the acceptable level of 0.78. The mean running time of the GRATA was 11.98 s. The ICC value was 0.91 (P<0.01; 95% confidence interval [95% CI]: 0.87-0.94), the SEM 0.26 s and the SWC 0.17 s.

 

 

#12 Comparable Outcomes between Bone-Patellar Tendon-Bone Autograft and Quadriceps Tendon Autograft for ACL Reconstruction in an All-Female Soccer Player Cohort with Mean 4.8-Year Follow Up

Reference: J ISAKOS. 2023 Nov 10:S2059-7754(23)00592-8. doi: 10.1016/j.jisako.2023.11.002.

Authors: Zachary J Herman, Neilen Benvegnu, Sahil Dadoo, Audrey Chang, Robert Scherer, Ehab M Nazzal, Emre Anil Özbek, Janina Kaarre, Jonathan D Hughes, Bryson P Lesniak, Dharmesh Vyas 

Download link: https://www.jisakos.com/action/showPdf?pii=S2059-7754%2823%2900592-8

Summary: The purpose is to compare functional outcomes, return to soccer rates, and revision rates in an all-female soccer player cohort undergoing quadriceps tendon (QT) autograft ACLR versus bone-patellar tendon-bone (BPTB) autograft ACLR. Female soccer players who sustained an ACL rupture and underwent primary anatomic, single-bundle ACLR with BPTB autograft or QT autograft were included. Demographic and surgical characteristics were collected. Outcomes of interest included Tegner score, International Knee Documentation Committee (IKDC) score, Marx score, return to soccer rates, and failure rates. Data on 23 patients undergoing BPTB autograft ACLR and 14 undergoing QT autograft ACLR was available. Average age was 18.7 years, and average follow up was 4.8 years. Overall, 76% (28/37) returned to soccer and 5.4% (2/37) underwent revision ACLR. No major significant differences were found in demographic or surgical characteristics. No differences were found in postoperative IKDC scores, preoperative, postoperative, or change from pre-to postoperative Marx activity scores, or pre-and postoperative Tegner scores between the groups. QT autograft ACLR patients had significantly less change in Tegner scores pre-to postoperatively compared to the BTPB autograft ACLR group (0.6 + 1.2 versus 2.1 + 1.8; p = 0.02). Both groups had similar rates of return to soccer [78% (18/23) BPTB autograft ACLR versus 71% (10/14) QT autograft ACLR; p = 0.64]. BPTB autograft ACLR and QT autograft ACLR produced comparable, successful functional and return to soccer outcomes in this all-female soccer player cohort study. Larger, prospective studies are needed to improve the strength of conclusions and provide more information on the optimal graft choice for female soccer players.

 

 

#13 The impact of crowd effects on home advantage of football matches during the COVID-19 pandemic-A systematic review

Reference: PLoS One. 2023 Nov 16;18(11):e0289899. doi:10.1371/journal.pone.0289899. eCollection 2023.

Authors: Sihang Wang, Yang Qin

Download link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0289899

Summary: This review aimed to (1) analyze whether the home advantage was diminished; (2) investigate the impact of the crowds' support on the match outcome and team performance; (3) explore the bias of the referee without crowds. Based on the PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines, this systematic review searched of literature was conducted in December 2022. The keywords related to soccer, COVID-19 and home advantage were used. The search returned 135 articles. After screening the records against set criteria, 28 articles were analyzed. Results showed that the absence of crowds would reduce the home advantage of teams, but the findings varied by country. Most leagues have evidence that without the support of the spectators, their technical, tactical and physical performances would be worse. The referee seems likely to be fairer when the spectators are absent. Therefore, crowd supports is an important factor affecting home advantage, the clubs can at least try to strengthen the home advantage and increase the winning possibility by encouraging spectators to enter the stadium or reducing the ticket price.

 

 

#14 Mental, physiological and medical considerations for elite football players in the Saudi Pro League: a call for action

Reference: BMJ Open Sport Exerc Med. 2023 Nov 7;9(4):e001789. doi: 10.1136/bmjsem-2023-001789. eCollection 2023.

Authors: Ismail Dergaa, Helmi Ben Saad, Abdelfatteh El Omri, Juan David Peña Duque, Mokthar Chaabane, Karim Chamari

Download link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10632892/pdf/bmjsem-2023-001789.pdf

 

 

#15 Effects of tactical dimension and situational variables in throw-ins on the offensive performance in football

Reference: PLoS One. 2023 Nov 15;18(11):e0294317. doi: 10.1371/journal.pone.0294317. eCollection 2023.

Authors: Claudio A Casal, Vasilis Armatas, José Luis Losada, Michalis Mitrotasios

Download link: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0294317

Summary: The aim of the study was to describe the usual practices in the execution of throw-ins by La Liga teams during the 2021-2022 season, identify tactical indicators related to the outcome of plays that start with a throw-in, calculate their predictive power, and finally analyse the influence of situational variables on the effectiveness of these plays. A total of 2,658 throw-ins, during 80 matches were analysed. Two UEFA PRO coaches designed an ad hoc observation instrument "Thrinfoot" and two observers coded the data after a training process. Inter and intra-observer reliability was calculated using Cohen´s Kappa coefficient, revealing almost perfect agreement. Multinomial logistic regression was applied to predict the throw-ins outcome (p<0.05). Results showed how fast throw-ins (OR = 0.7, p<0.05), without pressing (OR = 0.4, p<0.001), short and backwards (OR = 0.3, p<0.01) in the central zone (OR = 0.6, p<0.01) and made in the 16´-30´ (OR = 0.6, p<0.01), 61´-75´ (OR = 0.7, p< 0.05) periods, presented higher probabilities of continuing with possession. Match status losing>2 (OR = 4.1, p< 0.05) showed higher probabilities of success. On the other hand, throw-ins from the defensive zone presented higher probabilities of unsuccess (OR = 8.6, p<0.01) and losing possession (OR = 1.8, p<0.01). Finally, the bottom teams showed the highest probability of losing the ball. In conclusion, tactical indicators such as duration, press, distance, direction and zone were identified as key performance indicators and the situational variables team quality, match status and time influence the outcome of throw-ins. These findings provide valuable insights to coaches regarding the factors that influence the outcome of throw-ins. This allows them to design optimal strategies for both executing and defending these plays based on the game situation and their immediate aims.

 

 

#16 #ReadyToPlay: health problems in women's football-a two-season prospective cohort study in the Norwegian premier league

Reference: Br J Sports Med. 2023 Nov 15:bjsports-2023-107141. doi: 10.1136/bjsports-2023-107141.

Authors: Roar Amundsen, Solveig Thorarinsdottir, Benjamin Clarsen, Thor Einar Andersen, Merete Møller, Roald Bahr

Download link: https://bjsm.bmj.com/content/bjsports/early/2023/11/15/bjsports-2023-107141.full.pdf

Summary: The aim was to describe the prevalence, incidence and burden of all health problems in the Norwegian women's premier league. During the 2020 and 2021 seasons, players in the Norwegian women's premier league reported all health problems (sudden-onset injuries, gradual-onset injuries and illnesses) weekly, using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. Team medical staff diagnosed reported problems using the Sport Medicine Diagnostic Coding System. We calculated average weekly prevalence, incidence and burden of all health problems reported. We included 294 players (age: 22±4 years) from 11 teams. Response rate to the weekly questionnaire was 79%. On average, 32% (95% CI: 31% to 33%) of the players reported at least one health problem at any time and 22% (95% CI: 21% to 23%) reported a substantial health problem negatively affecting their training volume or performance. The overall incidence was 10.7 health problems per 1000 hours of football exposure. Sudden-onset injuries were most severe (68% of the total time loss), followed by gradual-onset injuries (25%) and illnesses (8%). Thigh was the most common injury location (26%), while knee injuries were most severe, causing 42% of the total injury time loss. Anterior cruciate ligament (ACL) injuries alone caused 30% of the total injury time loss. One in five players had a health problem negatively affecting their training volume or performance at any time. Sudden-onset injuries represented the most burdensome health problem. Thigh injuries were most frequent, while knee injuries, ACL injuries especially, were most severe.