A Bibliometric Analysis of Soccer Biomechanics

Soccer biomechanics is a field that applies principles of mechanics to improve performance and reduce the risk of injury for soccer players. The purpose of this research is to perform a mapping review of the existing knowledge in the current literature, identify leading researchers and institutions, and explore emerging research topics. After conducting a mini literature review, a bibliometric analysis was carried out using the VOSviewer software. The data imported into VOSviewer was obtained from the Scopus database and included 951 records. The analysis performed included: (a) performance analysis to calculate the number of records per year and the authors with the most citations; (b) science mapping analysis (co-authorship, co-citation, and bibliographic coupling); and (c) clustering analysis through the co-occurrence analysis of author keywords. Our findings highlight a significant growth in research publications on soccer biomechanics over the past few decades, with a notable increase in the number of articles published in high-impact journals. Additionally, the clustering analysis resulted in seven clusters, with each cluster providing valuable insights into different aspects of soccer biomechanics, which clearly reflects the multifaceted nature of the field

The Influence of Unstable Load and Traditional Free-Weight Back Squat Exercise on Subsequent Countermovement Jump Performance

The purpose of the present study was to examine the effects of a back squat exercise with unstable load (UN) and traditional free-weight resistance (FWR) on subsequent countermovement jump (CMJ) performance. After familiarisation, thirteen physically active males with experience in resistance training visited the laboratory on two occasions during either experimental (UN) or control (FWR) conditions separated by at least 72 h. In both sessions, participants completed a task-specific warm-up routine followed by three maximum CMJs (pre-intervention; baseline) and a set of three repetitions of either UN or FWR back squat exercise at 85% 1-RM. During the UN condition, the unstable load was suspended from the bar with elastic bands and accounted for 15% of the total load. Post-intervention, three maximum CMJs were performed at 30 s, 4 min, 8 min and 12 min after the last repetition of the intervention. The highest CMJ for each participant was identified for each timepoint. No significant increases (p > 0.05) in jump height, peak concentric power, or peak rate of force development (RFD) were found after the FWR or UN conditions at any timepoint. The lack of improvements following both FWR and UN conditions may be a consequence of the low percentage of unstable load and the inclusion of a comprehensive task-specific warm-up. Further research is required to explore higher UN load percentages (>15%) and the chronic effects following the implementation of a resistance training programme

Identifying soccer players’ playing styles: a systematic review

Identifying playing styles in football is highly valuable for achieving effective performance analysis. While there is extensive research on team styles, studies on individual player styles are still in their early stages. Thus, the aim of this systematic review was to provide a comprehensive overview of the existing literature on player styles and identify research areas required for further development, offering new directions for future research. Following the PRISMA guidelines for systematic reviews, we conducted a search using a specific strategy across four databases (PubMed, Scopus, Web of Science, and SPORTDiscus). Inclusion and exclusion criteria were applied to the initial search results, ultimately identifying twelve studies suitable for inclusion in this review. Through thematic analysis and qualitative evaluation of these studies, several key findings emerged: (a) a lack of a structured theoretical framework for player styles based on their positions within the team formation, (b) absence of studies investigating the influence of contextual variables on player styles, (c) methodological deficiencies observed in the reviewed studies, and (d) disparity in the objectives of sports science and data science studies. By identifying these gaps in the literature and presenting a structured framework for player styles (based on the compilation of all reported styles from the reviewed studies), this review aims to assist team stakeholders and provide guidance for future research endeavors

Analysis of playing styles in European football: insights from a visual mapping approach

Performance analysis is a rapidly evolving field in football and a subject of extensive international scientific research. Recognizing playing styles is now considered essential for effective performance analysis. This study aimed to create a map of 174 teams from 11 European leagues that could, through visualization, provide practical insights applicable to football teams' daily practice. The t-distributed Stochastic Neighbor Embedding (t-SNE) method was used to reduce the dimensions of 19 tactical situations derived from previous research. The resulting two coordinates were employed to generate a scatter plot, and simultaneous k-means cluster analysis (k = 11) was conducted. Greece (86%) and Scotland (83%) had the highest percentages of teams within the same cluster as their country's average, while Germany (11%) and Croatia (10%) had the lowest percentages. In terms of cluster dispersion, England ranked first with 9 clusters, followed by Spain and Germany with 7 clusters, while Greece and Scotland had the least with 2 clusters. The visualization and clustering of teams led to the following conclusions. a) There are variations in playing styles not only between teams from different countries but also within the same country, particularly when there is a disparity in quality. b) Coaches' philosophies and implemented strategies significantly influence the adoption of playing styles by teams. These findings provide valuable information for coaches, analysts, and team scouts, assisting them in their respective roles. By understanding the diverse playing styles present in European football, practitioners can tailor their approaches to optimize team performance and gain a competitive edge

Identifying soccer teams’ styles of play: a scoping and critical review

Identifying and measuring soccer playing styles is a very important step toward a more effective performance analysis. Exploring the different game styles that a team can adopt to enable a great performance remains under-researched. To address this challenge and identify new directions in future research in the area, this paper conducted a critical review of 40 research articles that met specific criteria. Following the 22-item Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, this scoping review searched for literature on Google Scholar and Pub Med database. The descriptive and thematic analysis found that the objectives of the identified papers can be classified into three main categories (recognition and effectiveness of playing styles and contextual variables that affect them). Critically reviewing the studies, the paper concluded that: (i) factor analysis seems to be the best technique among inductive statistics; (ii) artificial intelligence (AI) opens new horizons in performance analysis, and (iii) there is a need for further research on the effectiveness of different playing styles, as well as on the impact of contextual variables on them

A multivariate and cluster analysis of diverse playing styles across European football leagues

Performance analysis is a valuable tool for team coaches and has been the subject of extensive study in international research. A significant portion of the scientific literature in the field of football has been devoted to studying playing styles in recent years. The identification of playing styles is now regarded as crucial for conducting an efficient performance analysis. This study aimed to explore the variances in playing styles among eleven distinct European domestic football leagues. A comprehensive sample of 2996 matches, accounting for 5992 observations, was scrutinized. Nineteen latent variables, representing thirty-eight different game styles previously identified in sports science literature, served as the basis for this investigation. Multivariate analysis of variance (MANOVA) revealed significant differences across countries in ten out of nineteen variables. The variables with the highest effect sizes (partial η2) were transition game, effective game, and defending aggressively, implying that these factors contributed to the most substantial differences among countries. To visualize these disparities, the t-distributed stochastic neighbor embedding (t-SNE) method was employed. Subsequently, k-means clustering was applied to the t-SNE results, grouping the eleven participating countries into five distinct clusters. A unique playing style was discerned in the Scottish league (Cluster 4), setting it apart from all other leagues. Other clusters included Austria, Belgium, and Switzerland (Cluster 1); Spain, Turkey, and Croatia (Cluster 2); Greece and Italy (Cluster 3); and Germany and England (Cluster 5). The findings offer valuable insights for coaches, managers, scouts, and sporting directors, potentially guiding the development of effective game styles and enhancing recruitment strategies for both players and coaches