Postural threat can induce conscious involvement in movement control. This internal focus has been implicated in compromising attentional processing efficiency during postural control, leading to behavioral adaptations that might increase the risk of falling in the elderly. It is suggested that electroencephalography (EEG) coherence, or 'communication', between T3 (verbal-analytical) and Fz (motor-planning) regions may provide an objective measure of internal focus in learned movement skills. However, it is currently unknown whether this experimental technique can be applied to the control of gait and posture; skills which develop early in life, without the use of declarative knowledge/explicit verbal cues to guide performance. We validate the utility of the EEG T3-Fz coherence analysis in a postural task. A total of 24 young adults produced small voluntary swaying movements in medial-lateral or anterior-posterior direction under conditions that directed their attentional focus either internally or externally. Although EEG coherence was sensitive to voluntary changes in attentional focus, the lack of observed between-group (High/Low-trait-reinvestment) difference in coherence may suggest that younger adults cannot be assumed to utilize explicit verbal cues to control voluntary postural sway unless explicitly instructed to do so. As a result, while these results indicate that EEG T3-Fz is a valid technique for assessing attentional focus in postural tasks, our data do not support the clinical application of this method of analysis in providing an objective indication of trait-reinvestment in tasks involving voluntary postural sway.

RESUMOO objetivo do estudo foi comparar a eficiência do comportamento tático entre os jogadores de futebol de diferentes categorias etárias. A amostra foi composta por 400 jogadores divididos em quatro categorias (sub-11, sub-13, sub-15 e sub-17), que realizaram no total 23.855 ações táticas. Para avaliação da eficiência do comportamento tático dos jogadores foi utilizado o FUT-SAT. Para o tratamento estatístico, foram realizadas análises descritivas, os testes Kolmogorov-Smirnov, Kruskal-Wallis, Mann-Whitney e foi considerado um nível de significância de p<0,05. Os resultados indicam que a eficiência do comportamento tático tende a aumentar ao longo do tempo, com exceção da categoria Sub-15 que apresenta uma queda acentuada em relação às demais. Assim é possível concluir que existem variações na eficiência do comportamento tático de jogadores de futebol de diferentes categorias etárias. Palavras-chave: Futebol. Comportamento tático. Categorias etárias. ABSTRACTThe aim of this study was to compare the tactical behavior efficiency between soccer players from different age levels. The sample comprised 400 players from four age groups , who performed 23,855 tactical actions. Players' tactical behavior efficiency was assessed through FUT-SAT. Statistical procedures included descriptive analysis and the tests Kolmogorov-Smirnov, Kruskal-Wallis and Mann-Whitney. The significance level adopted was p<0.05. Results indicated that the tactical behavior efficiency tends to increase over time, except for the U-15 age level, that displayed an accentuated drop in relation to the others. It is concluded that the efficiency of tactical behavior of the players in soccer displayed differences across different age levels.

This study aims to expand the process of tactical assessment of soccer players through the development and validation of a video-based test based on core tactical principles of play. The TacticUP video test for soccer is composed of offensive and defensive video sequences of 11vs11 soccer situations. Participants should choose the most appropriate solution for each video sequence. Content validity was established based on a panel of nine experts from four different countries. Construct validity was assessed through the comparison between players with distinct expertise levels. Comparisons between groups’ final scores showed statistical differences ( p < 0.05) in 10 out of the 15 variables assessed, in which the expert group displayed higher values compared to the non-expert group. Face validity examined the acceptability and suitability of the test by players. Reliability was determined through the test–retest method for each video sequence, and Cohen’s Kappa values ranged from 0.622 to 1.0. Therefore, the TacticUP video test showed adequate content, construct, and face validity and was a reliable measure of perceptual-cognitive and decision-making skills in soccer. We overcame limitations from previous video-based tests in soccer by introducing situations concerning off-the-ball movements in both offensive and defensive phases. The practical applications of this test are: (i) it can be used to monitor players’ perceptual-cognitive and decision-making skills; (ii) the test is based on players’ response selection in a video-based test, which enables the measurement of their perceptual-cognitive and decision-making skills based on the core tactical principles of play; (iii) generate players’ tactical profile considering their perceptual-cognitive and decision-making skills based on core tactical principles of play; and (iv) measure the effectiveness of intervention/training programs on the development of perceptual-cognitive and decision-making skills.

da Silva, CD, Machado, G, Fernandes, AA, Teoldo, I, Pimenta, EM, Marins, JCB, and Garcia, ES. Muscle damage–based recovery strategies can be supported by predictive capacity of specific global positioning system accelerometry parameters immediately after soccer match-load. J Strength Cond Res 35(5): 1410–1418, 2021—Soccer match-load can be linked to recovery kinetic markers. However, match variability hinders the magnitude of relationship between parameters of interest. Therefore, we examined the correlation between 21 global positioning system accelerometry (GPS-A) parameters and changes in serum creatine kinase (CK) concentrations, muscle soreness (MS), and perceptive recovery quality (PRQ) assessed at baseline (1 h before) and post (0 minute, 2, 4, and 24 hours) a standardized 90-minute match-simulation in 20 university players. Global positioning system accelerometry (15 Hz) data were tested as manufacturer and configurable thresholds. Four GPS-A parameters showed moderate to very large correlations with CK changes at all time points (average speed [avgSP, r = 0.75 to r = 0.84]; running symmetry foot strikes [RSfst, r = 0.53–0.63]; running series [RunS, r = 0.53–0.61]; and acceleration distance [AccD ≥ 1.5 m·s−2; r = 0.46–0.61]). Sprint count (≥2 m·s−2), AccD (≥2.5 m·s−2) and speed exertion (SpEx) had a moderate to large correlation (r = 0.46–0.56) with CK changes from 2 to 24 hours. Changes in MS at 0 minute had large correlation with avgSP (r = 0.53) and moderate with deceleration distance (≥−2 and ≥−3 m·s−2; r = 0.47, r = 0.48, respectively). The PRQ changes had moderate inverse correlation with avgSP at 0 minute (r = −0.39) and SpEx at 2 h (r = −0.69). Our results suggest that during a simulated soccer protocol with a standard workload, only the avgSP has practical application for predicting CK changes over 24 hours, allowing for a decision-making toward a postgame recovery based on previously known CK cutoff points. Global positioning system accelerometry parameters and subjective variables did not demonstrate relevant correlation.

In soccer, different tactical behaviours of individuals are necessary to perform well as a team. The demands put on players from different positional roles can be manipulated in training through small-sided and conditioned games and tactical behaviours might be stimulated. The aim of this study was to assess the effects of positional role in tactical behaviour of U-17 youth soccer players based on core tactical principles in a four-a-side small-sided and conditioned game. The sample was comprised of 268 U-17 youth Brazilian soccer players. They were of five positional roles: centre backs; fullbacks; defensive midfielders; offensive midfielders; and forwards. The instrument used to collect and analyse data was the System of Tactical Assessment in Soccer (FUT-SAT). Results revealed that players of different positional roles showed no differences in the quantity of tactical actions performed. Moreover, forwards showed lower quality of tactical behaviour in the defensive phase (M=69.1, SD=16.0; p&lt;.05) compared to fullbacks (M=77.0, SD=13.1; p&lt;.05) and worse in actions far from the ball that ensured team cohesion in the defensive phase (M=69.7, SD=22.8; p&lt;.05) compared to fullbacks (M=80.1, SD=18.4; p&lt;.05). This study showed that the four-a-side format allows U-17 players to perform a similar quantity of tactical actions regardless of their positional role, but the player’s positional role influence quality of their tactical behaviour. Therefore, this structure might be used for trainings that promotes similar tasks and stimuli for players’ development that do not focus on specific tactical roles.

No abstract

O objetivo deste estudo é verificar as associações entre o período do ano de nascimento dos jogadores e a eficiência do comportamento tático sobre o desempenho tático em jogadores de futebol da categoria sub-17. A amostra foi composta por 6308 ações táticas, realizadas por 100 jogadores. O instrumento utilizado foi o Sistema de Avaliação Tática no Futebol (FUT-SAT). Utilizou-se a Regressão Logística Multinomial para verificação da associação entre o desempenho tático com a eficiência do comportamento dos princípios táticos e a data de nascimento dos jogadores. Verificaram-se associações positivas entre a eficiência do comportamento tático e o desempenho tático para os princípios Espaço, Penetração e Contenção. Foram encontradas associações positivas entre o período do ano de nascimento e o desempenho tático para os jogadores nascidos no 2º e 3º quartil. Conclui-se que para esta amostra, a eficiência do comportamento tático e a data de nascimento influenciaram o desempenho tático.

-Aims:The aim of this study was to assess the visual search strategy of soccer players from different age groups. Methods: The sample comprised 51 youth soccer players. The instrument used to collect and analyse data was the Mobile Eye. This system is used to verify gaze behaviour through visual focus. Players were grouped according to their age group: U-13 (17), U-15 (17), U-17 (17). Participants were presented with a video based test. Visual search stimuli were grouped into five categories: "player in possession of the ball"; "ball"; "teammates"; "opponent"; "space". The number and time of fixations made by players, in each stimuli category was analysed. One-way ANOVA was performed to compare the three groups. Results: Results displayed significant differences in one of the categories. The "space" category displayed significant differences in the number of fixations between U-13 (74.35±12.41) compared to U-15 (58.78±14.22) and U-17 (61.88±16.44) soccer players. No other significant differences were found in other categories. Conclusion: The U-13 players employed most of their visual search related with "space" compared with players from the U-15 and U-17 age groups. These findings are important for coaches and researchers to understand how visual search strategy change according to age group.