Injury prevention in male youth soccer: Current practices and perceptions of practitioners working at elite English academies

Forty-one practitioners inclusive of physiotherapists, sports scientists and strength and conditioning coaches from the academies of elite soccer clubs in the United Kingdom completed an on-line questionnaire which examined their: (1) background information; (2) perceptions of injury occurrence and risk factors; (3) screening and return to play; and (4) approach to designing and delivering injury prevention programmes with a response rate of 55% (41/75). Contact injuries were the most common mechanism reported and players between 13–16 years of age were perceived to be at the greatest risk. Pertinent risk factors included: reduced lower limb and eccentric hamstring strength, proprioception, muscle imbalances, and under developed foundational movement skills. Joint range of motion, jump tests, the functional movement screen, overhead and single leg squats were the most utilised screening methods. Training modalities rated in order of importance included: resistance training, flexibility development, agility, plyometrics and balance training. Training frequency was most commonly once or twice per week, during warm-ups, independent sessions or a combination of both. Injury prevention strategies in this cohort appear to be logical; however, the classification of injury occurrence and application of screening tools to identify “at risk” players do not align with existing research. The frequency and type of training used may also be insufficient to elicit an appropriate stimulus to address pertinent risk factors based on current recommendations.     

Estimated maturity status and perceptions of adult autonomy support in youth soccer players

Abstract

In this study, we examined the relations between biological maturity status, body mass index, age, and perceptions of adult autonomy support in the context of youth soccer. A total of 70 female and 43 male soccer players, aged 9 – 15 years, completed three adult-specific versions (i.e. mother, father, coach) of the perceived autonomy support subscale from the Interpersonal Style Scale. The participants' percent predicted adult stature was used as an estimate of biological maturity status. Multiple linear regression analyses revealed that advanced maturity status in male players predicted lower perceptions of autonomy support from the coach. Maturity status was unrelated to perceptions of autonomy support from the coach in female soccer players, and paternal and maternal autonomy support in male and female players. Age and body mass index were unrelated to perceptions of adult (i.e. coach, mother, father) autonomy support in male and female players.     

Estimated maturity status and perceptions of adult autonomy support in youth soccer players

In this study, we examined the relations between biological maturity status, body mass index, age, and perceptions of adult autonomy support in the context of youth soccer. A total of 70 female and 43 male soccer players, aged 9 - 15 years, completed three adult-specific versions (i.e. mother, father, coach) of the perceived autonomy support subscale from the Interpersonal Style Scale. The participants' percent predicted adult stature was used as an estimate of biological maturity status. Multiple linear regression analyses revealed that advanced maturity status in male players predicted lower perceptions of autonomy support from the coach. Maturity status was unrelated to perceptions of autonomy support from the coach in female soccer players, and paternal and maternal autonomy support in male and female players. Age and body mass index were unrelated to perceptions of adult (i.e. coach, mother, father) autonomy support in male and female players.     

Age and maturity related differences in motor coordination among male elite youth soccer players

This study investigated differences in generic and soccer specific motor coordination, as well as speed and agility depending on age and maturity in elite youth soccer players (U10-U15, N = 619). Measurements included body height, body weight and sitting height to estimate age at peak height velocity (APHV); three Körperkoordinationstest für Kinder subtests (i.e. jumping sideways (JS), moving sideways (MS), balancing backwards (BB)) to assess generic motor coordination; the UGent dribbling test for soccer specific motor coordination; a 5m/30m sprint and T-test for speed and agility, respectively. Age specific z-scores of the predicted APHV identified players as earlier, on time or later maturing. (M)ANOVA analyses showed significant age by maturity interaction effects for the speed and agility test cluster, revealing maturity related differences in U14 and U15 players. Next to an overall higher performance with age for all test clusters (η² 0.080–0.468), earlier maturing players outperformed their later maturing peers in 5m/30m sprinting. The opposite was seen for JS and BB. So, players’ maturity status should be taken into account to adequately value performance in talent identification. Also, the focus on characteristics that appear to be minimally biased by an earlier maturational timing (i.e. motor coordination) should be increased.     

Dribbling determinants in sub-elite youth soccer players

Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s^?1, P < 0.01); reduced CoM mediolateral (0.91 ± 0.05 vs. 1.14 ± 0.16 m, P < 0.05) and vertical (0.19 ± 0.01 vs. 0.25 ± 0.03 m, P < 0.05) RoMs; higher right stride cadence (+20%, P < 0.05) with lower variability (P < 0.05); reduced hip and knee flexion RoMs (P < 0.05). In conclusion, faster players are able to run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.     

Estimating fat-free mass in elite youth male soccer players: cross-validation of different field methods and development of prediction equation

This study determined the most effective field method for quantifying fat-free mass (FFM) in elite youth male soccer players compared to dual X-ray absorptiometry (DXA) values and to develop prediction equations for FFM based on anthropometric variables. Forty-one male elite-standard youth soccer players, ages 16.2–18.0 years, undertook FFM assessments including bioelectrical impedance analysis, and different skinfold-based prediction equations. DXA provided a criterion measure of FFM. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses to develop soccer-specific prediction equations. Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998) equations showed the lowest biases, and no significant, standardized, and substantial differences against DXA. The new youth soccer-specific anthropometric equation explained 91% of the DXA-derived FFM variance using three circumferences, eight skinfolds, and one bone breadth. All field methods compared in this study may not be adequate for estimating FFM in elite youth male soccer players, except the equations of Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998). We recommend the use of the new soccer-specific equation proposed in this study as a valid alternative to DXA to quantify FFM among elite youth male players.     

Academic performance and self-regulatory skills in elite youth soccer players

Abstract

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12–16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.     

Academic performance and self-regulatory skills in elite youth soccer players

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self-efficacy) of elite youth soccer players aged 12-16 years (n = 128) with those of 164 age-matched controls (typical students). The results demonstrate that the elite youth soccer players are more often enrolled in the pre-university academic system, which means that they are high academic achievers, compared with the typical student. The elite players also report an increased use of self-regulatory skills, in particular self-monitoring, evaluation, reflection, and effort. In addition, control students in the pre-university system had more highly developed self-regulatory skills than those in the pre-vocational system, whereas no difference was observed within the soccer population. This suggests that the relatively stronger self-regulatory skills reported by the elite youth soccer players may be essential for performance at the highest levels of sport competition and in academia.     

Reliability and validity of field-based fitness tests in youth soccer players

This study aimed to establish between-day reliability and validity of commonly used field-based fitness tests in youth soccer players of varied age and playing standards, and to discriminate between players without (“unidentified”) or with (“identified”) a direct route to professional football through their existing club pathway. Three-hundred-and-seventy-three Scottish youth soccer players (U11–U17) from three different playing standards (amateur, development, performance) completed a battery of commonly used generic field-based fitness tests (grip dynamometry, standing broad jump, countermovement vertical jump, 505 (505COD) and T-Drill (T-Test) change of direction and 10/20 m sprint tests) on two separate occasions within 7–14?days. The majority of field-based fitness tests selected within this study proved to be reliable measures of physical performance (ICC?=?0.83–0.97; p?p?2 (7)?=?101.646, p?相似文献   

Knowledge and perceptions of sport psychology within English soccer

The aim of the present study was to examine knowledge and perceptions of applied sport psychology within English soccer. National coaches (n?=?8), youth academy directors (n?=?21) and academy coaches (n?=?27) were surveyed using questionnaire and interview methods. Questionnaire results revealed a lack of knowledge of sport psychology that appeared to underpin some of the most significant barriers to entry for sport psychologists. These included lack of clarity concerning the services of a sport psychologist, problems fitting in and players' negative perceptions of sport psychology. Overall, however, lack of finance was the highest rated barrier. Six barrier dimensions emerged from the interview data: negative perceptions of psychology, lack of sport psychology knowledge, integrating with players and coaching staff, role and service clarity, practical constraints, and perceived value of sport psychology. These findings were broadly compatible with the survey data, with finance emerging as a major barrier and misconceptions of sport psychology being common. Our conclusions are discussed in relation to the practical implications of the study for both applied research and the provision of sport psychology services within English soccer.     

The relative age effect in youth soccer across Europe

The potential asymmetries in the birth-date distributions of youth soccer players across ten European countries (2175 age citations) were considered. First, we examined the birth-dates of players representing national youth teams in international competitions. Second, the birth-dates of players representing professional club teams in international youth tournaments were analysed. Kolmogorov-Smirnov tests were used to assess differences between observed and expected birth-date distributions. Regression analyses were employed to examine the relationship between month of birth and number of players in the different samples. The results showed an over-representation of players born in the first quarter of the selection year (from January to March) for all the national youth selections at the under-15 (U-15), U-16, U-17 and U-18 age categories, as well as for the UEFA U-16 tournaments and Meridian Cup. Players with a greater relative age are more likely to be identified as "talented" because of the likely physical advantages they have over their "younger" peers. Some options for reducing the relative age effect are offered.     

Knowledge and perceptions of sport psychology within English soccer

The aim of the present study was to examine knowledge and perceptions of applied sport psychology within English soccer. National coaches (n = 8), youth academy directors (n = 21) and academy coaches (n = 27) were surveyed using questionnaire and interview methods. Questionnaire results revealed a lack of knowledge of sport psychology that appeared to underpin some of the most significant barriers to entry for sport psychologists. These included lack of clarity concerning the services of a sport psychologist, problems fitting in and players' negative perceptions of sport psychology. Overall, however, lack of finance was the highest rated barrier. Six barrier dimensions emerged from the interview data: negative perceptions of psychology, lack of sport psychology knowledge, integrating with players and coaching staff, role and service clarity, practical constraints, and perceived value of sport psychology. These findings were broadly compatible with the survey data, with finance emerging as a major barrier and misconceptions of sport psychology being common. Our conclusions are discussed in relation to the practical implications of the study for both applied research and the provision of sport psychology services within English soccer.     

欧洲青少年足球选材模式的研究热点

通过对欧洲青少年足球选材模式的3个研究热点进行分析,了解国内外足球选材模式发展动态,并与我国现阶段足球项目选材的现状进行比较。结果显示:运动员身体形态和生理机能的方法虽预测性较差,却对长期追踪成才意义重大;心理选材越来越受到重视,热点是在运动认知能力的研究上;基因选材作为未来研究的趋势,可以提高选材的准确性和科学性。     

Differences in game reading between selected and non-selected youth soccer players

Applying an established theory of cognitive development―Skill Theory―the current study compares the game-reading skills of youth players selected for a soccer school of a professional soccer club (n = 49) and their non-selected peers (n = 38). Participants described the actions taking place in videos of soccer game plays, and their verbalisations were coded using Skill Theory. Compared to the non-selected players, the selected players generally demonstrated higher levels of complexity in their game-reading, and structured the information of game elements―primarily the player, teammate and field―at higher complexity levels. These results demonstrate how Skill Theory can be used to assess, and distinguish game-reading of youth players with different expertise, a skill important for soccer, but also for other sports.     

The performance environment of the England youth soccer teams

In the present study, we examined the performance environment of the England youth soccer teams. Using a semi-structured protocol with a prospective sample, national coaches (n = 6), sport scientists (n = 3), and players (n = 4) were interviewed directly following international tournaments about the factors that positively and negatively influenced performance. Qualitative content analysis revealed the following factors as major positive influences on performance: adhering to a consistent tournament strategy, player understanding, strong team cohesion, organized entertainment activities, detailed knowledge of opposition, an effective physical rest/recovery strategy, and previous tournament experience. Major factors perceived to have negatively influenced performance included: over-coaching, player boredom, player anxiety, physical superiority of the opposition, physical fatigue over the tournament, problems sleeping, and lack of information on the opposition. Eight overall dimensions emerged to describe the performance environment: planning and organization, physical environment, tactical factors, development and performance philosophy, psychological factors, physical factors, social factors, and coaching. The findings support recent work that suggests the performance environment is multifaceted, with performance being contingent upon a broad range of interacting factors that go beyond the traditional psychosocial and physical domains.     

Practice and play as determinants of self-determined motivation in youth soccer players

Abstract

Based upon predictions derived from the Developmental Model of Sports Participation, we tested whether hours in domain-specific play (self-led activities) and practice (coach-led activities) during childhood (~5–12 year) in an elite group of youth soccer players from the UK (N = 144) were related to motivation. Independent analysis of three different age groups (Under 13, 15 and 17 year) did not show relations between play and practice activities during childhood and global measures of motivation. However, secondary analysis showed that when controlling for years in soccer, years in the UK Academy system were negatively related to global indices of self-determined motivation (SDI) and positively related to controlled motivation for the oldest players. Despite predictions, there was no evidence that play during childhood was positively related to more SDI. Prospective research is recommended to enable more robust conclusions about the role of early developmental practice activities, especially early specialisation in a high-performance system, on both skill and psychosocial development.     

The performance environment of the England youth soccer teams

Abstract

In the present study, we examined the performance environment of the England youth soccer teams. Using a semi-structured protocol with a prospective sample, national coaches (n = 6), sport scientists (n = 3), and players (n = 4) were interviewed directly following international tournaments about the factors that positively and negatively influenced performance. Qualitative content analysis revealed the following factors as major positive influences on performance: adhering to a consistent tournament strategy, player understanding, strong team cohesion, organized entertainment activities, detailed knowledge of opposition, an effective physical rest/recovery strategy, and previous tournament experience. Major factors perceived to have negatively influenced performance included: over-coaching, player boredom, player anxiety, physical superiority of the opposition, physical fatigue over the tournament, problems sleeping, and lack of information on the opposition. Eight overall dimensions emerged to describe the performance environment: planning and organization, physical environment, tactical factors, development and performance philosophy, psychological factors, physical factors, social factors, and coaching. The findings support recent work that suggests the performance environment is multifaceted, with performance being contingent upon a broad range of interacting factors that go beyond the traditional psychosocial and physical domains.     

Self-regulation and performance level of elite and non-elite youth soccer players

Abstract

In learning and development, self-regulation can be described as the extent to which individuals are metacognitively, motivationally, and behaviourally proactive participants in their learning process (Zimmerman, 1989 Zimmerman, B. J. 1989. A social cognitive view of self-regulated academic learning. Journal of Educational Psychology, 81: 329–339. [Crossref], [Web of Science ®] , [Google Scholar], 2006 Zimmerman, B. J. 2006. “Development and adaptation of expertise: The role of self-regulatory processes and beliefs”. In The Cambridge handbook of expertise and expert performance, Edited by: Ericsson, K. A., Charness, N., Feltovich, P. J. and Hoffman, R. R. 705–722. New York: Cambridge University Press. [Crossref] , [Google Scholar]). We examined the relationship between self-regulation and performance level in elite (n = 159) and non-elite (n = 285) youth soccer players aged 11–17 years (mean 14.5 years, s = 1.4). The players completed a questionnaire that assessed planning, self-monitoring, evaluation, reflection, effort, and self-efficacy. A logistic regression analysis was performed (controlling for age) to determine which self-regulatory aspects were associated with players' performance level (elite vs. non-elite). High scores on reflection and effort were associated with a higher level of performance. Findings suggest that elite players may be more aware of their strong and weak points as well as better able to translate this awareness into action. In addition, elite players appear to be more willing to invest effort into practice and competition. It is suggested that these better developed self-regulatory skills may translate into a more effective learning environment and ultimately result in an increased capacity for performance in elite players relative to their non-elite peers.     

Biomechanical mechanisms of jumping performance in youth elite female soccer players

ABSTRACT

We aimed to determine key biomechanical parameters explaining age-related jumping performance differences in youth elite female soccer players. Multiple biomechanical parameters from countermovement (CMJ) squat (SJ) and drop (DJ) jump testing of elite female soccer players (n = 60) within the same national training centre were analysed across ages 9-11y, 12-14y and 15-19y. Effects of age group and jump type on jump height were found, with the older jumping higher than the younger groups in all jumps (P < 0.05). For DJ, higher reactive strength index was found for older, compared to each younger group (P < 0.001). For CMJ and SJ, peak power was the most decisive characteristic, with significant differences between each group for absolute peak power (P < 0.0001) and body-weight-normalised peak power in CMJ (57 ± 7W/kg, 50 ± 7W/kg, 44.7 ± 5.5W/kg; P < 0.05) and between the older and each younger group in SJ (56.7 ± 7.1W/kg, 48.9 ± 7.1W/kg, 44.6 ± 6W/kg; P < 0.01). Age-related differences in jumping performance in youth elite female soccer players appear to be due to power production during standing jumps and by the ability to jump with shorter ground contact times during reactive jumps.