The impact phase of drop punt kicking for maximal distance and accuracy

Impact is an important aspect of the kicking skill. This study examined foot and ball motion during impact and compared distance and accuracy punt kicks. Two-dimensional high-speed video (4000 Hz) captured data of the shank, foot and ball through impact of 11 elite performers kicking for maximal distance and towards a target 20 m in distance. Four phases were identified during impact, with an overall reduction in foot velocity of 5.0 m · s^?1 (± 1.1 m · s^?1) and increase in ball velocity of 22.7 m · s^?1 (± 2.3 m · s^?1) from the start to end of contact. Higher foot velocity was found in distance compared to accuracy kicks (22.1 ± 1.6 m · s^?1 vs. 17.7 ± 0.9 m · s^?1, P < 0.05), and was considered to produce the significant differences in all impact characteristics excluding foot-to-ball speed ratio. Ankle motion differed between the kicking tasks; distance kicks were characterised by greater rigidity compared to accuracy kicks evident by larger force (834 ± 107 N vs. 588 ± 64 N) and smaller change in ankle angle (2.2 ± 3.3° vs. 7.2 ± 6.4°). Greater rigidity was obtained by altering the position of the ankle at impact start; distance kicks were characterised by greater plantarflexion (130.1 ± 5.8° vs. 123.0 ± 7.9°, P < 0.05), indicating rigidity maybe actively controlled for specific tasks.     

Biomechanical considerations of distance kicking in Australian Rules football

Kicking for distance in Australian Rules football is an important skill. Here, I examine technical aspects that contribute to achieving maximal kick distance. Twenty-eight elite players kicked for distance while being videoed at 500 Hz. Two-dimensional digitized data of nine body landmarks and the football were used to calculate kinematic parameters from kicking foot toe-off to the instant before ball contact. Longer kick distances were associated with greater foot speeds and shank angular velocities at ball contact, larger last step lengths, and greater distances from the ground when ball contact occurred. Foot speed, shank angular velocity, and ball position relative to the support foot at ball contact were included in the best regression predicting distance. A continuum of technique was evident among the kickers. At one end, kickers displayed relatively larger knee angular velocities and smaller thigh angular velocities at ball contact. At the other end, kickers produced relatively larger thigh angular velocities and smaller knee angular velocities at ball contact. To increase kicking distance, increasing foot speed and shank angular velocity at ball contact, increasing the last step length, and optimizing ball position relative to the ground and support foot are recommended.     

Influence of football size on kicking performance in youth Australian rules footballers

In Australian rules football structured increases in ball size during development end with the transition to the Size 5 (adult) ball at the Under-15 age group. This study assessed changes in kick technique and performance in experienced junior performers when using Size 4 and 5 Australian rules footballs. Participants (n = 22, 13.77 ± 0.61 years) performed drop punt kicks in 2 representative tasks; a Decision-Making Test (DMT) (n = 14) and Set-Shot Test (SST) (n = 14 + 8). Results indicate participants sustained their level of kick performance (accuracy and quality of ball spin) in both tests when using a Size 5 football. Sustained kick performance in the DMT primarily resulted from adaptations to time-point technical measures at ball release. No significant differences were detected for technical measures between ball sizes in the SST. A dynamic kicking task (DMT) in combination with ball size manipulation may have placed greater demand on skill execution in comparison to a self-paced kicking task (SST). Results provide initial support for the utility of challenging representative dynamic and self-paced tasks, such as the DMT and SST used here for Australian football, for skill testing and practice in sport     

Home advantage and player nationality in international club football

Abstract

The home advantage effect was investigated at a team and player level in Union of European Football Associations (UEFA) Champions League football using in-depth performance and disciplinary variables. Performance analysis revealed that the home team scored more goals, had more shots on and off target, had a greater share of possession, and won more corners than the away team. There was an opposite trend for disciplinary variables, with the home team committing less fouls than the away team, and receiving less yellow and red cards. There were home advantage effects at player level for goals, total shots, shots on target, assists, and yellow cards, as found in the team analysis. In addition, foreign players demonstrated a home advantage effect for goals scored, whereas domestic players scored an equivalent number of goals at home and away venues. Results are discussed in relation to the home advantage literature and wider implications for the sport.     

A mathematics-based new penalty area in football: tackling diving

ABSTRACT

A novel penalty area (PA) for football (soccer) is proposed; it is based on considering mathematically the actual scoring possibility on the 2 dimensions near the goal. It is shown that the 150-year-old rectangular area is mathematically disproportionate; this can be causing too much diving or simulation by players around the goal and also too many matches that are decided unfairly. The goal or objective is to reduce these problems – and others – with a new PA based on the proposed scoring potential measure which is in turn based on the angle towards the goal line (between posts) and the distance to the centre of this line.     

体育院系足球普修课踢球技术的教学顺序研究

合理地安排足球的各种踢球教学顺序，可以使学生尽快地掌握其技术动作。对足球踢球技术教学两种不同顺序的安排进行了研究认为，合理的教学顺序应为：先教脚背内侧踢球，再教正脚背踢球，最后再教脚内侧踢球。     

足球技术教学中促进学生综合能力提高的实验研究

在足球技术教学中运用现代的教育理念和方法,对提高学生的综合能力素质进行了实验对照.结果显示,通过创新教学模式能显著提高教学质量和学生的综合素质,促使学生掌握学法、锻炼能力、培养创新精神.     

Psychological characteristics of developing excellence in elite youth football players in English professional academies

ABSTRACT

This mixed-longitudinal prospective study examined the development of psychological characteristics of developing excellence in relation to the career progression of elite youth football players. In a 20-month period, 111 academy football players aged 11–16 completed the Psychological Characteristics of Developing Excellence Questionnaire (PCDEQ) on 1–5 occasions. This combination of single and repeated assessments resulted in a mixed-longitudinal sample of 226 completed PCDEQs. Players were then prospectively tracked, and their scholarship status assessed at follow-up, at age U17. Multilevel modelling revealed that coping with performance and developmental pressures scores increased with age, and that Category 1–2 academy scholars (4.35 ± 0.61) scored higher than Category 3–4 academy scholars (3.99 ± 0.67) and non-scholars (4.02 ± 0.78) (p < .05). Evaluating performances and working on weaknesses scores increased with age for Category 1–2 academy scholars (U12-U14 vs. U15-U16 = 5.16 ± 0.48 vs. 5.38 ± 0.45), compared to non-scholars (U12-U14 vs. U15-U16 = 5.11 ± 0.59 vs. 5.03 ± 0.71) (p < .05). Imagery use during practice and competition scores decreased with age (U12-U14 vs. U15-U16 = 4.45 ± 0.66 vs. 4.29 ± 0.70) (p < .05). A blend of PCDEs may facilitate optimal career progression. Football academies should develop players’ PCDEs, with a particular focus on developing their coping skills and their ability to realistically evaluate performances and work on weaknesses.     

职业足球联赛球场暴力的成因及对策

中外男子足球职业联赛球场暴力行为有逐年上升趋势；球场暴力从表面上看与裁判的判罚有直接关系，但实际是多种综合因素导致；遏制足球球场暴力，关键要做好对广大球迷的教育与疏导工作，同时要加强完善职业足球裁判员管理制度，减少误判、错判发生的机率，发挥媒体正面宣传作用；警方应进一步加强球场的安全保卫工作，借鉴世界足球先进国家在防范与治理球场暴力方面的经验。     

足球操在足球教学准备活动中运用的实验研究

借鉴动作技能迁移规律，遵循体操创编原则和足球运动特点编制足球操，将其运用于足球教学的准备活动中，对常规足球准备活动进行了适宜的改革。实验结果表明：足球操有助于学生动作技术的形成，有利于提高教学质量，加速教学进程。     

Defining the attributes for specific playing positions in football match-play: A complex systems approach

ABSTRACT

Introduction

Talent identification and development programmes that retain and develop athletes are integral to the sporting success of National Governing Bodies in football. Currently, player attributes are studied in isolation without considering the complexity of interacting components of football performance. The current study applied a systems analysis framework to describe, in a structured and systematic way, the attributes for specific playing positions in football match-play. Methods: Eight high-level football coaches were interviewed. Models of the interacting attributes were developed for each position using Work Domain Analysis (WDA). Results: Six WDA models detail the attributes associated with each playing position. The models identified purposes of playing positions (restrict opposition actions, organise and coordinate, building up of offence, goal scoring and stretch opposition), performance-related measures and the functions required to achieve the playing position purposes (game play, psychological functions, time and space and player actions). Critically, the relationships between the purposes, measures, functions, processes, and objects are described in the models.     

Women’s association football (soccer) in Brisbane,Queensland 1921–1933: new perspectives on early competition

ABSTRACT

In September 1921, two representative women’s teams played association football (soccer) on the Brisbane Cricket Ground in Queensland, Australia. The crowd size, approximately 10,000, was not commensurate with those attending matches featuring Dick, Kerr Ladies in England during the same period, but it was nonetheless a significant crowd at a match now widely acknowledged as Australia’s first public game of women’s association football. New evidence suggests it may have been the first between representative female association football sides, with players selected from local teams.

Contemporary accounts note the match as a single event. Regular organised competition did not occur until the early 1970s, but led to the formation of a national association in 1974. An overview of current literature and new archival research highlights the emergence of a strong culture around woman’s association football that begins before the Brisbane Cricket Ground match. The evidence presents a possible imbalance between what occurred and what has been recorded, and suggests a much more prolonged, if somewhat fragmented, engagement with association football between 1921 and 1933 in southern Queensland. The emergence of competition in Brisbane in the 1920s foregrounds the city’s – and, with it, Queensland’s – contribution to the history and development of Australian women’s football.     

Analysis of direct free kicks in the women's football World Cup 2007

Abstract

The location and outcome of all free kicks taken directly at goal in the 2007 women's football World Cup were assessed to identify areas with the most goal-scoring potential and assist with tactical decisions and training design. Video of all free kicks taken directly at goal in the 32 games was captured and the location of the ball on the pitch was calculated from pitch markings and image pixel coordinates using a customized curve-fitting method. The outcome of each free kick was determined and for those that resulted in a goal or were saved, information on ball flight time and the placement of the ball relative to the goal was reported. All seven free kicks that resulted in a goal were taken from a central area within 7 m of the penalty circle, placed at the edge of the goal within approximately 1 m of the goalpost, and had an average flight time of 1.09 s, which was significantly faster than for those that were saved. All free kicks directed towards the bottom and centre of the goal resulted in straightforward saves for the goalkeeper. It is recommended that teams should consider a direct shot from free kicks awarded within 7 m of the penalty circle. For free kicks from wide areas and areas further from the goal, players should be aware of their individual ability and only take a shot when they perceive the probability of scoring a goal to be high. Otherwise, alternative attacking strategies should be considered to avoid an easy turnover of possession.     

Relative age effect in Spanish association football: Its extent and implications for wasted potential

Abstract

Spain is one of the largest and most successful powers in international youth football, but this success has not extended to the national team. This lack of continued success seems to indicate a loss of potential. The relative age effect has been detected in football in many countries. Understanding the extent of this bias in the youth teams of Spanish elite clubs may help to improve selection processes and reduce the waste of potential. Comparisons between players from: the Spanish Professional Football League, all age categories of these clubs' youth teams, the Under-17 to Under-21 national teams, the national team, and the Spanish population, show a constant tendency to under-represent players from the later months of the selection year at all age groups of youth and Under-17 to Under-21 national teams. Professional and national team players show a similar but diminished behaviour that weakens with ageing, which suggests that talent identification and selection processes can be improved to help better identify potential talent early on and minimize wasted potential.     

Fluid and electrolyte balance in elite male football (soccer) players training in a cool environment

There are few data in the published literature on sweat loss and drinking behaviour in athletes training in a cool environment. Sweat loss and fluid intake were measured in 17 first-team members of an elite soccer team training for 90 min in a cool (5°C, 81% relative humidity) environment. Sweat loss was assessed from the change in body mass after correction for the volume of fluid consumed. Sweat electrolyte content was measured from absorbent patches applied at four skin sites. Mean (?± s) sweat loss during training was 1.69?±?0.45 l (range 1.06?-?2.65 l). Mean fluid intake during training was 423?±?215 ml (44?-?951 ml). There was no apparent relationship between the amount of sweat lost and the volume of fluid consumed during training (r ² = 0.013, P = 0.665). Mean sweat sodium concentration was 42.5?±?13.0 mmol?·?l^?1 and mean sweat potassium concentration was 4.2?±?1.0 mmol?·?l^?1. Total salt (NaCl) loss during training was 4.3?±?1.8 g. The sweat loss data are similar to those recorded in elite players undergoing a similar training session in warm environments, but the volume of fluid ingested is less.     

中国职业足球俱乐部联盟建立的必要性

建立中国职业足球联盟的必要性在于:(1)可以弥补足球项目管理的宏观和微观性失灵,增强俱乐部的博弈力量;(2)使所有者监督成为可能;(3)联盟可改变委托-代理性质,从而产生高效的管理绩效;(4)职业足球俱乐部的成长需要更为高效、专业的组织提供所需的公共服务,以解决公共性失灵问题;(5)有效解决俱乐部高成本问题。提出未来中国职业联盟的构想:(1)明确联盟与足协的权力边界;(2)联盟要保护职业俱乐部之间的竞争与合作;(3)足协成员进入联盟决策层,是防止俱乐部业主合谋的约束机制。     

关于在中小学校建立足球俱乐部的可行性研究

通过对部分学校进行实地调查，与部分专家、教师、学生进行面谈获得翔实的第一手资料，认为在有条件的中小学建立足球俱乐部是可行的。其依据为：一是学生崇尚足球运动的热情为学校建立足球俱乐部提供了会员基础；二是得到了教育行政部门、体育行政部门、足协、有关专家、部分学校领导的支持和学生家长、体育教师、非体育教师及社会的支持与肯定；三是国内外中小学校现有的足球俱乐部为建立同类型俱乐部提供了成功的范例和宝贵的经验。     

普通高校足球技术考核项目标准化设置的研究

运用测量统计学的有关原理 ,对经过筛选的足球技术考核项目的信度、效度、难度、鉴别力进行了标准化检验 ,以便科学地设置普通高校足球选项课学期技术考核项目     

A method to assess the influence of individual player performance distribution on match outcome in team sports

This study developed a method to determine whether the distribution of individual player performances can be modelled to explain match outcome in team sports, using Australian Rules football as an example. Player-recorded values (converted to a percentage of team total) in 11 commonly reported performance indicators were obtained for all regular season matches played during the 2014 Australian Football League season, with team totals also recorded. Multiple features relating to heuristically determined percentiles for each performance indicator were then extracted for each team and match, along with the outcome (win/loss). A generalised estimating equation model comprising eight key features was developed, explaining match outcome at a median accuracy of 63.9% under 10-fold cross-validation. Lower 75th, 90th and 95th percentile values for team goals and higher 25th and 50th percentile values for disposals were linked with winning. Lower 95th and higher 25th percentile values for Inside 50s and Marks, respectively, were also important contributors. These results provide evidence supporting team strategies which aim to obtain an even spread of goal scorers in Australian Rules football. The method developed in this investigation could be used to quantify the importance of individual contributions to overall team performance in team sports.     

Hydration,sweat and thermoregulatory responses to professional football training in the heat

Abstract

This study examined the relationship between intensity of training and changes in hydration status, core temperature, sweat rate and composition and fluid balance in professional football players training in the heat. Thirteen professional football players completed three training sessions; “higher-intensity” (140 min; HI₁₄₀), “lower-intensity” (120 min; LI₁₂₀) and “game-simulation” (100 min; GS₁₀₀). Movement demands were measured by Global Positioning System, sweat rate and concentration were determined from dermal patches and body mass change. Despite similar environmental conditions (26.9 ± 0.1°C and 65.0 ± 7.0% relative humidity [Rh]), higher relative speeds (m · min^?1) and increased perceptions of effort and thermal strain were observed in HI₁₄₀ and GS₁₀₀ compared with LI₁₂₀ (P < 0.05). Significantly (P < 0.05) greater sweat rate (L · h^?1) and electrolyte losses (g) were observed in HI₁₄₀ and GS₁₀₀ compared with LI₁₂₀. Rate of rise in core temperature was correlated with mean speed (r = 0.85), session rating of perceived exertion (sRPE) (r = 0.61), loss of potassium (K⁺) (r = 0.51) sweat rate (r = 0.49), and total sweat loss (r = 0.53), with mean speed the strongest predictor. Sodium (Na⁺) (r = 0.39) and K⁺ (r = 0.50) losses were associated with total distance covered. In hot conditions, individualised rehydration practices should be adopted following football training to account for differences in sweat rate and electrolyte losses in response to intensity and overall activity within a session.