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Sam Robertson Bart Spencer Nicole Back Damian Farrow 《Journal of sports sciences》2019,37(11):1280-1285
Representative learning design provides a framework for the extent to which practice simulates key elements of a performance setting. Improving both the measurement and analysis of representative learning design would allow for the refinement of sports training environments that seek to replicate competition conditions and provide additional context to the evaluation of athlete performance. Using rule induction, this study aimed to develop working models for the determination of high frequency, representative events in Australian Rules football kicking. A sample of 9005 kicks from the 2015 Australian Football League season were categorised and analysed according to the following constraints: type of pressure, kick distance, possession source, time in possession, velocity and kick target. The Apriori algorithm was used to develop two models. The first consisted of 10 rules containing the most commonly occurring constraint sets occurring during the kick in AF, with support values ranging from 0.15 to 0.22. None of the rules contained more than three constraints and confidence values ranged from 0.63 to 0.84. The second model considered ineffective and effective kick outcomes and displayed 70% classification accuracy. This research provides a measurement approach to determine the degree of representativeness of sports practice and is directly applicable to various team sports. 相似文献
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随着全国青少年校园足球特色学校规模的不断扩大,富有足球天赋的优秀苗子会不断涌现,我国青少年足球训练中心的建设与发展趋势势不可挡。运用文献资料法、访谈法和现场考察法等研究方法对英国足球青训学院新的分类系统及新的分类系统下各类足球学院管理评价模式进行实证研究。研究认为：英国足球青训学院依据关键绩效产出理论划分为4类足球学院,其不同的培养模式体现了新分类系统的完整性、科学性和可操作性;基于10项关键业绩指标体系下的英国足球青训学院管理模式具有客观性与严谨性等特点,可为我国各级各类青少年足球训练中心制度的建立与完善提供一定的理论指导和实践参考。 相似文献
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Mostafa Zarei Hamed Abbasi Abdolhamid Daneshjoo Tohid Seif Barghi Nikki Rommers Oliver Faude 《Journal of sports sciences》2018,36(21):2447-2454
This study examined the long-term effects of the 11+ on physical performance in adolescent male football (soccer) players. Eighty-two 14- to 16-year-old male football players (11+ = 42 players, control = 40 players) participated. Teams were randomised to control (CON) and intervention (INT) groups. INT applied the 11+ injury prevention programme for 30 weeks at least twice a week as a warm-up. CON performed their standard warm-up. Motor performance tests were conducted 1 week prior and 1 week after the competition season. We used magnitude-based inferences and linear mixed-effects models to analyse performance test results. INT showed superior results compared to CON in the vertical jump height 7.5% (95%-CI 4.4%, 10.7%), the Bosco 15-s-jump test 7.2% (95%-CI 2.2%, 12.4%), and the Illinois agility test ?2.6% (95%-CI ?4.1%, ?1.1%). Possibly beneficial effects in favour of INT were found in the 9.1 m sprint test ?3.1% (95%-CI ?6.1%, 0.1%). Possibly harmful effects (i.e. in favour of CON) were observed in the dribbling test 2.8% (95%-CI ?0.8%, 6.4%). The 11+ warm-up programme can improve different performance measures in football players. Coaches might implement additional dribbling drills next to the 11+ to achieve improvements observed in dribbling ability when using a regular warm-up programme. 相似文献
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《运动与健康科学(英文)》2023,12(5):619-629
BackgroundTraumatic brain injury can be caused by head impacts, but many brain injury risk estimation models are not equally accurate across the variety of impacts that patients may undergo, and the characteristics of different types of impacts are not well studied. We investigated the spectral characteristics of different head impact types with kinematics classification.MethodsData were analyzed from 3262 head impacts from lab reconstruction, American football, mixed martial arts, and publicly available car crash data. A random forest classifier with spectral densities of linear acceleration and angular velocity was built to classify head impact types (e.g., football, car crash, mixed martial arts). To test the classifier robustness, another 271 lab-reconstructed impacts were obtained from 5 other instrumented mouthguards. Finally, with the classifier, type-specific, nearest-neighbor regression models were built for brain strain.ResultsThe classifier reached a median accuracy of 96% over 1000 random partitions of training and test sets. The most important features in the classification included both low- and high-frequency features, both linear acceleration features and angular velocity features. Different head impact types had different distributions of spectral densities in low- and high-frequency ranges (e.g., the spectral densities of mixed martial arts impacts were higher in the high-frequency range than in the low-frequency range). The type-specific regression showed a generally higher R2 value than baseline models without classification.ConclusionThe machine-learning-based classifier enables a better understanding of the impact kinematics spectral density in different sports, and it can be applied to evaluate the quality of impact-simulation systems and on-field data augmentation. 相似文献
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Andreas Hohmann 《体育科研》2019,(4):1-9
足球是世界第一运动，在德国拥有广泛的群众基础，那么如何有效地对足球运动员进行科学合理的筛选就成为了一项重要的课题。本文由德国拜罗伊特大学体育系运动训练科学小组完成，目的是为了揭示足球人才在一般运动测试中所表现的中期预后有效性以及从实验结果计算出的足球特定表现分数。在此之前已经对包括体操、滑雪和网球在内的几项人才筛选计划实施了运动诊断分析。然而，与大多数其他运动相比，足球运动对这种早期测试的预测价值尚不清楚。测试对象由参与德国富尔达地区运动表现能力测试（FMC）的U9二年级儿童组成（N=2 965）。FMC是一个对测试者基础运动表现能力的筛查，由两个人体测量学特征参数和德国运动能力表现测试（GMT6-18）的8个测试项目组成，并增加了一个投掷球测试。测试数据来自2011-2014年在德国富尔达地区参与测试的所有儿童，并记录了至2016-2017赛季结束时（2017年9月30日）选择足球（N=316）的儿童的足球比赛表现水平。然后依据比赛表现水平的高低将球员分别分配到4个不同的表现级别中，并使用ANOVA，比值比和判别分析法确定运动测试的预后有效性，并将测试结果与测试儿童在U12~U15年龄段所表现出的足球运动表现水平进行分析，最终得出9项基础运动测试的预后相关性。 相似文献
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The relationships between team performance indicators and match outcome have been examined in many team sports, however are limited in Australian Rules football. Using data from the 2013 and 2014 Australian Football League (AFL) regular seasons, this study assessed the ability of commonly reported discrete team performance indicators presented in their relative form (standardised against their opposition for a given match) to explain match outcome (Win/Loss). Logistic regression and decision tree (chi-squared automatic interaction detection (CHAID)) analyses both revealed relative differences between opposing teams for “kicks” and “goal conversion” as the most influential in explaining match outcome, with two models achieving 88.3% and 89.8% classification accuracies, respectively. Models incorporating a smaller performance indicator set displayed a slightly reduced ability to explain match outcome (81.0% and 81.5% for logistic regression and CHAID, respectively). However, both were fit to 2014 data with reduced error in comparison to the full models. Despite performance similarities across the two analysis approaches, the CHAID model revealed multiple winning performance indicator profiles, thereby increasing its comparative feasibility for use in the field. Coaches and analysts may find these results useful in informing strategy and game plan development in Australian Rules football, with the development of team-specific models recommended in future. 相似文献
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跨学科研究虽早已为体育学界所熟知,但对研究本身的内涵、特征、应用原则等基本问题的探索仍相对欠缺。研究选择聚焦体育人文科学,结合跨学科研究理论与体育人文科学现状,明确跨学科研究的价值内涵及其在体育人文科学中的价值定位。研究认为,以体育发展现实中的复杂问题为导向是跨学科研究的前提,识别、选择与熟识体育人文相关学科知识是跨学科研究的基础,整合问题的相关学科见解并构建更全面的新认识是跨学科研究的实现方式。据此提出实现路径：深入体育发展现实探寻亟待跨学科研究的体育人文问题,完善体育人文科学的跨学科研究范式与学科知识基础,推进从单向的学科知识借鉴转向互动的跨学科知识互鉴。 相似文献
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T. E. Carl Woods J. Annette Raynor Lyndell Bruce Zane McDonald 《Journal of sports sciences》2015,33(11):1132-1140
This study examined whether skill tests were predictive of status in junior Australian football. Players were recruited from the 2013 under 18 (U18) West Australian Football League competition and classified into two groups: elite (state U18 squad representative; n = 25; 17.9 ± 0.5 years) and subelite (nonstate U18 squad representative; n = 25; 17.3 ± 0.6 years). Both groups completed the Australian football kicking (AFK) and Australian football handballing (AFHB) tests, assessing kicking accuracy/ball speed and handballing accuracy on dominant and nondominant sides. A multivariate analysis of variance (MANOVA) modelled the main effect of “status”, whilst logistic regression models were built for the predictive analysis using the same test parameters. Between-group differences were noted across all parameters, with the combination of kicking accuracy and ball speed on the dominant and nondominant sides being the best predictor of status for the AFK test (wi = 0.25, AUC = 89.4%) and the combination of accuracy on the dominant and nondominant sides being the best predictor of status for the AFHB test (wi = 0.80, AUC = 88.4%). The AFK and AFHB tests are predictive of status, suggesting that their use is warranted as a means of talent identification in junior Australian football. 相似文献
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足球运动在世界范围内的普及化与社会化程度日益增强，各国（地区）若要获得全球化竞争中的优势，应注重探讨社会与足球运动发展的关系。通过对1993-2017年131个国家（地区）的人类发展指数与足球排名积分的面板数据建模，以揭示两者之间的关系。研究结果表明，不同国家（地区）的人类发展指数对足球运动发展的影响应建立个体和时点双固定效应模型，模型最高的R2为0.871 32，F检验值为71.014 65，P<0.001，该模型具备较高的解释能力。结论：固定效应模型在考虑历时性因素与不宜观测因素后，在1993-2017年阶段，人类发展指数对于足球运动的发展作用存在分化现象，尤其对亚洲与人口大国的足球运动发展存在制约作用，对南美洲与中等人口国家存在促进作用，人类发展指数与足球运动发展存在一定的或然关系。人类发展指数反映了社会发展的综合水平，对于存在制约效应的国家而言，应当着重考虑社会其它领域（经济、教育、医疗卫生等）与足球运动的互动、协同与融合发展。 相似文献
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Mikael Swarén Mikael Therell Anders Eriksson Hans-Christer Holmberg 《Sports Engineering》2013,16(4):255-264
The aim of the study was to develop an objective classification method for cross-country ski poles. A test device was designed to expose different pole models to maximal loading and impact tests. A load cell measured the axial forces in the pole shafts, and a laser distance meter measured shaft deflection when a load was applied via the wrist strap. In the loading tests, each shaft reached a plateau where no more force could be transferred. This maximal force transfer (MFT) value was a characteristic measure for flexural rigidity and thereby also strength. The developed test method enables a loading that is more similar to real-life skiing than a standard three-point bending test. Results show that the introduction of shaft indices for buckling strength is beneficial for comparison purposes. The MFT is a relevant parameter used in the characterization of poles. 相似文献
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Susana C. A. Póvoas Carlo Castagna José M. C. Soares Pedro M. R. Silva Mariana V. M. F. Lopes 《European Journal of Sport Science》2016,16(7):755-763
The purpose of this study was to examine the test–retest reliability and construct validity of three age-adapted Yo-Yo intermittent tests in football players aged 9–16 years (n?=?70) and in age-matched non-sports active boys (n?=?72). Within 7 days, each participant performed two repetitions of an age-related intensity-adapted Yo-Yo intermittent test, i.e. the Yo-Yo intermittent recovery level 1 children's test for 9- to 11-year-olds; the Yo-Yo intermittent endurance level 1 for 12- to 13-year-olds and the Yo-Yo intermittent endurance level 2 test for 14- to 16-year-olds. Peak heart rate (HRpeak) was determined for all tests. The distance covered in the tests was 57% (1098?±?680 vs. 700?±?272?m), 119% (2325?±?778 vs. 1062?±?285?m) and 238% (1743?±?460 vs. 515?±?113?m) higher (p?≤?.016), respectively for football-trained than for non-sports active boys aged 9–11, 12–13 and 14–16 years. The typical errors of measurement for Yo-Yo distance, expressed as a percentage of the coefficient of variation (confidence interval), were 11.1% (9.0–14.7%), 10.1% (8.1–13.7%) and 8.5% (6.7–11.7%) for football players aged 9–11, 12–13 and 14–16 years, respectively, with corresponding values of 9.3% (7.4–12.8%), 10.2% (8.1–14.0%) and 8.5% (6.8–11.3%) for non-sports active boys. Intraclass correlation coefficient values for test–retest were excellent in both groups (range: 0.844–0.981). Relative HRpeak did not differ significantly between the groups in test and retest. In conclusion, Yo-Yo intermittent test performances and HRpeak are reliable for 9- to 16-year-old footballers and non-sports active boys. Additionally, performances of the three Yo-Yo tests were seemingly better for football-trained than for non-sports active boys, providing evidence of construct validity. 相似文献
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We identified the perceptual–cognitive skills and player history variables that differentiate players selected or not selected into an elite youth football (i.e. soccer) programme in Australia. A sample of elite youth male football players (n?=?127) completed an adapted participation history questionnaire and video-based assessments of perceptual–cognitive skills. Following data collection, 22 of these players were offered a full-time scholarship for enrolment at an elite player residential programme. Participants selected for the scholarship programme recorded superior performance on the combined perceptual–cognitive skills tests compared to the non-selected group. There were no significant between group differences on the player history variables. Stepwise discriminant function analysis identified four predictor variables that resulted in the best categorization of selected and non-selected players (i.e. recent match-play performance, region, number of other sports participated, combined perceptual–cognitive performance). The effectiveness of the discriminant function is reflected by 93.7% of players being correctly classified, with the four variables accounting for 57.6% of the variance. Our discriminating model for selection may provide a greater understanding of the factors that influence elite youth talent selection and identification. 相似文献
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Luke Hogarth Vaughan Nicholson Jemima Spathis Sean Tweedy Emma Beckman Mark Connick 《Journal of sports sciences》2019,37(4):404-413
This study examined the validity of isometric strength tests for evidence-based classification in Para swimming. Thirty non-disabled participants and forty-two Para swimmers with physical impairment completed an isometric strength test battery designed to explain activity limitation in the freestyle discipline. Measures pertaining to dominant and non-dominant limb strength and symmetry were derived from four strength tests that were found to be reliable in a cohort of non-disabled participants (ICC = 0.85–0.97; CV = 6.4–9.1%). Para swimmers had lower scores in strength tests compared with non-disabled participants (d = 0.14–1.00) and the strength test battery successfully classified 95% of Para swimmers with physical impairment using random forest algorithm. Most of the strength measures had low to moderate correlations (r = 0.32 to 0.53; p ≤ 0.05) with maximal freestyle swim speed in Para swimmers. Although, fewer correlations were found when Para swimmers with hypertonia or impaired muscle power were analysed independently, highlighting the impairment-specific nature of activity limitation in Para swimming. Collectively, the strength test battery has utility in Para swimming classification to infer loss of strength in Para swimmers, guide minimum eligibility criteria, and to define the impact that strength impairment has on Para swimming performance. 相似文献
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Katrine Okholm Kryger Séan Mitchell Diwei Zhou Steph Forrester 《Sports Engineering》2018,21(4):401-408
Touch/control football boots are reportedly designed for optimal passing and dribbling. Little research exists on the effect of boot design on touch/control performance and no validated protocol has been developed for assessing passing and dribbling from an equipment focus. This study aimed to assess the effect of upper padding on dribbling and passing performance using a test–retest reliable test setup. Eight university players performed a protocol of dribbling, short and long passing in football boots with 0 and 6 mm of upper padding (Poron foam). The protocol was completed twice; the 0-mm padding results were used for test–retest validation, while the 0-mm versus 6-mm padding results were used to investigate the effect of padding. Dribbling performance was assessed though completion time, number of touches applied and lateral deviation from cones and passing performance through ball velocity and offset from target. The protocol demonstrated good test–retest reliability and indicated no significant differences in any of the 12 performance variables between the 0- and 6-mm padded boots. These findings suggest an element of design freedom in the use of padding within football boot uppers without affecting dribbling or passing performance. 相似文献
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文章对日本青少年足球后备人才培养的各种模式进行研究分析,归纳日本足球培养模式优势以及存在的问题,总结日本青少年足球培养的成功经验,为我国足球后备人才的培养和足球运动水平的提高提出相应的对策。 相似文献
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Existing methods for developing decision–making skill for Australian football umpires separate the physical and perceptual aspects of their performance. This study aimed to determine the efficacy of incorporating video-based decision-making training during high-intensity interval training sessions, specific for Australian football umpires. 20 amateur Australian football umpires volunteered to participate in a randomised control trial. Participants completed an 8-week training intervention in a conditioning only (CON; n=7), combined video-based training and conditioning (COM; n=7), or separated conditioning and video-based training (SEP; n=6) group. Preliminary and post-testing involved a Yo-Yo Intermittent Recovery Test (Yo-YoIR1), and 10x300m run test with an Australian football specific video-based decision-making task. Overall, changes in decision-making accuracy following the intervention were unclear between groups. SEP was possibly beneficial compared to COM in Yo-YoIR1 performance, whereas CON was likely beneficial compared to COM in 10x300m sprint performance. There was no additional benefit to completing video-based training, whether combined with, or separate to physical training, suggesting that this was not an optimal training method. For video-based training to be an effective decision-making tool, detailed feedback should be incorporated into training. It is recommended that longer conditioning and video-based training interventions be implemented to determine training effectiveness. 相似文献
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从足球运动员协调能力的概念、外部表现特征、内部结构特征以及分类模式四个方面对其进行探讨分析,研究表明,足球运动员的协调能力是一种复杂的能力,既不单纯的是身体素质,也不单纯的是运动技术。它是运动员在足球运动中,熟练地控制与调整自身身体动作、特别是下肢动作,最优化主动或被动完成各种有球与无球技术动作的能力。 相似文献
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Over the last two decades there has been a growth in research directly related to football. Although most of this research is focused on soccer (association football), there has been a steady increase in publications related to the other football codes. There is evidence of more systematic training and selection influencing the anthropometric profiles of players who compete at the highest level. Fitness is being optimized to cope with match demands while accommodating the need for specific requirements of positional roles. There is evidence of work rate being higher in contemporary football games than in previous decades, with consequences for training and dietary practices. Notation analysis of actions during matches is now used regularly to provide detailed objective feedback on performance to players and coaches. Training regimens are designed for game-specific purposes where possible. Sports psychologists working in a football context have a more eclectic body of knowledge to draw from. In the professional soccer clubs, the rewards associated with a successful investment in youth academies have helped to focus attention on talent identification and development models. It is a challenge to those specializing in science and football to contribute to the success of such schemes. 相似文献