Correct muscular activation of the body segments during an overhand throw is achieved when movement originates in the larger and more proximal legs and trunk and moves sequentially to the smaller, distal segments of the shoulder and arm. This sequence permits angular velocity to transfer progressively through the throw as part of an open kinetic chain. The athlete can summate angular velocity and segmental forces only if he is able to create a separation between the body segments during the movement pattern, and this separation is thus essential to effective segmental sequencing for activation of the trunk muscles to occur separately from distal segment motion. Limited mobility of the shoulder and scapula during the kinematic sequence will limit the ability of that segment to receive and contribute to the angular velocity of its proximal neighbors and to apply its own muscle torque to the throwing implement. This may result in compensatory motion of the proximal muscle groups to meet the demands placed on the body. To establish a link between compensatory activation of the trunk muscles and mobility in the rotator cuff and to apply this relationship to the pattern of the overhand throw, activity in the latissimus dorsi and external oblique/quadratus lumborum muscles was measured using surface electromyography in 40 college-age participants during arm flexion and lateral shoulder rotation. Muscle activation was recorded both before and after mobilization of relevant throwing muscles through targeted functional exercise. Results showed no significant change but suggested a general decrease in the level of peak muscle activation after participants engaged shoulder exercises. This is indicative of a downward trend in compensatory trunk activation during the initiation of shoulder motion. An increase in overall trunk muscle activity was also observed after exercise, which may imply a simultaneous engagement of the proximal throwing muscles in response to shoulder motion.

Made available in DSpace on 2016-06-02T20:19:14Z (GMT). No. of bitstreams: 1 3228.pdf: 1290499 bytes, checksum: b265c618eaa3f97d66f4b3ab4a0e214c (MD5) Previous issue date: 2010-08-19 / Universidade Federal de Minas Gerais / Repetitive throwing movement causes adaptations to athletes shoulders and predisposes them to the development of impingement symptoms. The objective of this study was to investigate if there are alterations in sensorimotor control and in the functional torque ratio of shoulder rotation in overhead athletes with impingement symptoms and to distinguish these from alterations due to sporting practice. To this end, three groups of subjects were evaluated: athletes with impingement symptoms, asymptomatic athletes and a control group of nonathletes. The participants were evaluated with a Biodex System 3 isokinetic dynamometer in a seated position with the shoulder at 90º of adduction and 90º of elbow flexion. Sensorimotor control was evaluated using an isometric torque steadiness evaluation. The isometric peak torque and submaximal torque steadiness at 35% peak torque were tested during medial rotation and lateral rotation of the shoulder. For each submaximal repetition, the standard deviation, coefficient of variation and time to stability were calculated. Only the standard deviation during medial rotation was greater in asymptomatic athletes than in control group. The isokinetic evaluation was carried out at the velocities 90°/s e 180°/s and 240°/ in concentric and eccentric modes. Peak torque-to-body weight and the functional torque ratios LREcc/MRCon and MREcc/LRCon were compared between groups. Asymptomatic athletes presented greater peak torque-to-body weight for concentric medial rotation at 180°/s and a lower LREcc/MRCon ratio at 90°/s and 180°/s than CG. The velocity 240°/s was excluded from the analyses because many participants were unable to reach the predetermined velocity in the eccentric tests, principally during lateral rotations. This difficulty was attributed to the low peak torque of lateral rotation that could be generated in this position. Overall, the results demonstrated that overhead sports training leads to adaptations in maximal torque and in the torque steadiness of medial rotation in healthy athletes, which may be related to throwing performance. Nevertheless, it is not possible to conclude that such alterations predispose these athletes to injury, since athletes with impingement symptoms group was not significantly different from the other groups in any of the evaluations. / O movimento repetitivo de arremesso gera adaptações no ombro de atletas, e os predispõe ao desenvolvimento de sintomas de impacto. O objetivo deste estudo foi investigar se há alterações no controle sensório-motor e na relação funcional de torque isocinético de rotação do ombro em atletas arremessadores com sintomas de impacto e diferenciar daquelas relacionadas a adaptações da prática esportiva. Sendo assim, foram avaliados três grupos de indivíduos: atletas com sintomas de impacto, atletas assintomáticos e um grupo controle de sujeitos não treinados. Os participantes foram avaliados no dinamômetro isocinético Biodex System 3, sentados, com o ombro posicionado a 90º de abdução e 90º de flexão do cotovelo. O controle sensório-motor foi avaliado por meio da flutuação do torque isométrico submáximo. O pico de torque isométrico e a flutuação do torque a 35% do pico de torque isométrico foram avaliados durante as rotações medial e lateral do ombro. Para cada repetição submáxima foram calculados o desvio-padrão, o coeficiente de variação e o tempo para atingir a estabilidade. Apenas o desvio-padrão de rotação medial foi maior no grupo de atletas assintomáticos comparado ao grupo controle. A avaliação isocinética foi realizada nas velocidades de 90°/s, 180°/s e 240°/s, nos modos concêntrico e excêntrico. O pico de torque/peso corporal e as relações funcionais de torque de rotação lateral excêntrico/rotação medial concêntrico (RLExc/RMCon) e rotação medial excêntrico/rotação lateral concêntrico (RMExc/RLCon) foram comparados entre os grupos. O grupo de atletas assintomáticos apresentou maior pico de torque/peso corporal de rotação medial concêntrica, a 180°/s, e menor relação RLExc/RMCon, a 90°/s e 180°/s, quando comparado ao controle. A velocidade de 240°/s foi excluída das análises, pois muitos participantes não conseguiram atingir a velocidade pré-determinada nos testes excêntricos, principalmente de rotação lateral. Essa dificuldade foi atribuída ao baixo pico de torque de rotação lateral capaz de ser gerado nessa posição. Em conjunto, os resultados demonstram que o treino de arremesso gera adaptações no torque máximo e na flutuação do torque submáximo de rotação medial em arremessadores saudáveis, possivelmente relacionados ao desempenho do arremesso. Entretanto, não é possível concluir se estas alterações predispõem esses atletas ao desenvolvimento de lesões, uma vez que o grupo de atletas com sintomas de impacto não se apresentou diferente dos outros grupos em nenhuma das situações avaliadas.

This research is an investigation of the Late Holocene technological transition from the spearthrower and dart to the bow and arrow in north central Texas. It is conducted through a theoretical approach that utilizes ethnographic research, experimental archaeology and the archaeological record to elucidate differences in the behaviors and hunting strategies of Late Archaic and Late Prehistoric groups. It first confirms that there was a transition. Second, a lithic analysis demonstrates that there are fundamental differences in the sizes of the stone dart and arrow points that relate to the propulsive requirements of the weapon systems. Third, it is shown these size differences constrain maintenance potentials and that indeed dart and arrow points exhibit stark differences in their life histories in spite of being employed for the same task. And finally, the faunal record suggests that this transition was associated with an increase in foraging efficiency.

Prevalence of physical inactivity in children and adolescents and the associated epidemic of obesity are increasing concerns. U.S. national health statistics indicate early adolescence (i.e., 10-14 years) appears to be a period of importance regarding physical activity, sedentary behavior, health-related physical fitness, and obesity trends. Considering a significant portion of their waking hours are spent in school, it is widely held that schools' should play a significant role in increasing students' physical activity and health-related physical fitness. To do this, physical education in schools focus on providing quality physical education programs that produce physically literate individuals who have the knowledge, skills, and confidence to enjoy a lifetime of health-producing physical activity. In effect, a call for developing a comprehensive and valid measure of physical literacy has been aptly expressed. Thus, the purpose of this dissertation was to test the psychometric properties of proposed models of physical literacy, examine correlates of the physical literacy factor, and investigate the significance of the relationship between physical literacy and interscholastic sport intention via structural equation modeling. Participants were 400 (231 female, 169 male) sixth-grade physical education students who completed three brief surveys assessing maturation, self-efficacy, self-esteem, knowledge and understanding, motivation, physical activity and sport participation, and interscholastic sport intention. In addition, students completed a sedentary behavior log, a health-related physical fitness assessment, and an overhand throwing skill assessment. Analyses offered overall support for the proposed physical literacy measurement models. Results also supported positive relationship Physical literacy was statistically significantly positively related physical activity and sport team participation, and significantly negatively related and screen-time sedentary behavior. Results also supported a positive path between physical literacy and interscholastic sport intention. The implications of promoting physical literacy within physical education are discussed in light of the three higher-order underlying factors of physical literacy.

An ongoing debate concerning Neandertal ecology is whether or not they utilized long range weaponry. The anteroposteriorly expanded cross-section of Neandertal humeri have led some to argue they thrusted their weapons, while the rounder cross-section of Late Upper Paleolithic modern human humeri suggests they threw their weapons. We test the hypothesis that Neandertal humeri were built to resist strains engendered by thrusting rather than throwing using finite element models of one Neandertal, one Early Upper Paleolithic (EUP) human and three recent human humeri, representing a range of cross-sectional shapes and sizes. Electromyography and kinematic data and articulated skeletons were used to determine muscle force magnitudes and directions during three positions of spear throwing and three positions of spear thrusting. Maximum von Mises strains were determined at the 35% and 50% cross-sections of all models. During throwing and thrusting, von Mises strains produced by the Neandertal humerus fell roughly within or below those produced by the modern human humeri. The EUP humerus performed similarly to the Neandertal, but slightly poorer during spear thrusting. This implies the Neandertal and EUP human humeri were just as well adapted at resisting strains during throwing as recent humans and just as well or worse adapted at resisting strains during thrusting as recent humans. We also did not find any correlation between strains and biomechanical metrics used to measure humeral adaptation in throwing and thrusting (retroversion angle, Imax/Imin, J). These results failed to support our hypothesis and suggest they were capable of using long distance weaponry.

The master's thesis discusses and solves the issues of technical and tactical training of hockey players. The program and methods of improving the technical and tactical actions of athletes when throwing the puck in hockey. The efficiency of the applied technique is proved. / В магистерской диссертации рассматриваются и решаются вопросы технико-тактической подготовки хоккеистов. Разработана программа и методика совершенствования технико-тактических действий спортсменов при вбрасывании шайбы в хоккее. Доказана эффективность примененной методики.

Quelques sites archéologiques comme Olympie, Stymphalos et Olynthe possèdent respectivement un répertoire faisant l’étude des armes de jet retrouvées durant une série de campagnes de fouilles archéologiques. Parmi ces indexes, figurent fréquemment des pointes de flèche, des balles de fronde et des saurotères (contrepoids de lance ou de javelot) provenant de différentes périodes historiques gréco-romaines. À travers les 20e et 21e siècle de notre ère, des spécialistes comme D. Robinson (1931), A. Snodgrass (1964), H. Baitinger (2001), C. Hagerman (2014) dédièrent une partie de leur expertise pour produire des synthèses sur ces objets jadis négligés. Ainsi, ils parvinrent à créer de grandes encyclopédies commentées composées de projectiles retrouvés en sol grec. À l’aide de ces bases de données, les archéologues militaires sont en mesure d’établir des datations et l’origine prétendue de certains types de projectiles. Jusqu’en 2015, les artéfacts militaires trouvés sur le site archéologique d’Argilos n’avaient jamais fait l’objet d’une étude de synthèse. D’abord, inspiré par de publications semblables, ces projectiles furent soumis à un inventaire sous forme de catalogue. Au total, deux types de balles de fronde en plomb, onze types de pointes de flèche et un type de saurotère furent identifiés. Finalement, ce nouveau contenu fut assujetti à des analyses comparatives avec d’autres sites archéologiques possédant des données similaires. Les conclusions découlant de ces analogies donnèrent naissance à la première typologie des armes de jet argilienne. Certes, les analyses se heurtèrent à certains obstacles, notamment à une compréhension de la quasi-inexistence d'une pointe de flèche typiquement "grecque" et à la confusion systématique quant à la distinction entre un saurotère et une pointe de javelot, voire possiblement un carreau de gastraphétès (une sorte d’arbalète imposante utilisée lors de sièges durant le 4e siècle av. J.-C.). En partie, ceci découle de l'historique d'échanges entre la Grèce et les autres peuples méditerranéens, balkaniques et orientaux. En outre, de nombreuses réformes militaires des périodes archaïque et classique provoquèrent une évolution constante sur les aspects stratégiques et les tactiques militaires. Considérant ces facteurs parmi tant d'autres et le fait qu'Argilos ait été une fondation grecque en territoire thraco-macédonien, la possibilité d'influence "étrangère" devient alors prépondérante sur la typologie des projectiles argiliens publiée dans le présent mémoire. Avec beaucoup d’espoir, nous croyons sans équivoque que ce travail de recherche contribuera grandement non seulement à l’histoire d’Argilos, mais aussi à l’étude des projectiles en Grèce du nord. / Archaeological sites such as Olympia, Stymphalos and Olynthus have complete catalogs that studied projectile-style weaponry found in a series of archaeological excavations. These so-called directories frequently include arrowheads, lead sling bullets and sauroters (spear or javelin counter-weights) from different Greco-Roman periods. Through the 20th and 21th centuries AD, specialists such as D. Robinson (1931), A. Snodgrass (1964), H. Baitinger (2001) and Haggerman (2014) dedicated some of their expertise to produce synthesises of these formerly ignored objects. Thus, they created some of the biggest commented encyclopaedias composed solely of projectiles found on Greek soil. Until 2015, all the weaponry found on the archaeological site of Argilos had never been the subject of a synthesis study. Firstly, inspired by similar studies, the projectiles were inventoried in a catalog format. In total, two types of lead sling bullets, eleven arrowhead types and one sauroter type were identified. Lastly, this new content was subjected to comparative analyses with sites containing similar data. The resulting conclusions from these analyses gave birth to the first Argilian weapon typology. Needless to say, the analyses ran into obstacles. In particular, the comprehension that there is almost no existence of a typical Greek arrowhead type and the systematic confusion when one has to distinguish a sauroter, a javelin head, and possibly a gastrasphetes bolt (a heavy large-sized crossbow used during sieges in the 4th century BC). In part, this stems from the historical exchanges between Greece and other Mediterranean, Balkan and oriental civilizations. Furthermore, many of the archaic and classical military reforms brought about a constant evolution on strategic and tactical matters. Considering these factors, among others, and the fact that Argilos was a Greek colony within a Thraco-macedonian territory, the possibility of foreign influence becomes predominant on the typology published in this present thesis. With much hope, we believe without a doubt that this work of research will contribute not only to the history of Argilos but also to the study of military projectiles in Northern Greece.

科学研究費補助金 研究種目:一般研究(C)(2) 課題番号:07680107 研究代表者:櫻井 伸二 研究期間:1995-1996年度

L’objectif principal de ce travail était de montrer empiriquement l’influence des contraintes culturelles sur la motricité humaine grâce à la mise en œuvre d’une expérience standardisée dans différents contextes culturels. L’exemple choisi est le tournage de poterie. Il s’agit d’une habileté artisanale ancienne qui est encore pratiquée dans différentes sociétés. En nous appuyant sur le cadre théorique de la psychologie écologique, nous avons étudié comment, à partir d’environnements culturels distincts —en France et dans deux communautés différentes en Inde— une même tâche (le tournage) est réalisée. La tâche expérimentale consistait à reproduire quatre formes dans deux masses. Deux expériences d’interversion ont également permis d’approfondir les résultats. En étudiant les stratégies d’action et le résultat final à partir des productions, on a pu mettre en évidence un ensemble de traits invariants dans les différents groupes. Ces invariants peuvent être interprétés comme une réponse aux contraintes de la tâche. Ainsi, quel que soit l’environnement culturel dans lequel le potier a appris le tournage, ce sont les principes du tournage qui ont été appris, indépendamment des conditions spécifiques d’exécution. En même temps, les résultats ont aussi montré des modulations culturelles dans la géométrie des productions et dans l’organisation temporelle de l’action. Il est possible d’interpréter ces variations comme des adaptations aux contraintes culturelles (matérielles et sociales) spécifiques à chaque groupe. En outre, nous avons observé que l’influence des contraintes sociales était aussi prégnante que celle des contraintes matérielles. Cette dernière observation nous a amené à proposer un projet de recherche postdoctorale ayant pour but d’analyser l’influence des modèles d’action (véhiculés par l’environnement social lors de l’apprentissage) sur les stratégies d’action du potier. / The main goal of our study was to provide an empirical demonstration of the influence of cultural constraints on motor performance. We focused on wheel throwing, an ancient craft skill that is still practiced in many societies. Inspired by the theoretical framework of the ecological approach to perception and action, we studied how a same task (throwing ceramic vessels on a wheel) was realised in different cultural environments in France and in two distinct communities in India. This study was made possible by the application of a standardised experimental approach within the different cultural contexts. The task consisted in reproducing four forms in two masses. The results were further developed by crossing experimental conditions between the two Indian populations. By analysing the action strategies and the vessels produced we were able to highlight a set of invariant characteristics. These invariants are interpreted as potters’ responses to the task constraints related of throwing a vessel. We suggest that all potters studied have acquired the principles underlying wheel throwing, independent of the (cultural) specifics of the conditions in which they evolve. At the same time, our results also revealed cultural modulations in the geometry of the vessels thrown and in the temporal organisation of the throwing activity. Such variations are interpreted as adaptations to the operative (material and social) cultural constraints specific to each group. Interestingly, social constraints were found to be as influential as material constraints (such as the type of wheel used). This latter observation led us to propose a post-doctoral research programme designed to analyse the influence of social action models (promulgated by the social environment during learning) on potter’s action strategies.

Author: Bc. Tomáš Zajíček Title: Analysis of game activities of goalkeeper during European Championship Under-21 2015. Objectives: The main objective is to analyse of game activities of goalkeeper on European Chapmionship Under-21 2015. Partial objectives: ranking of all matches on European Chapmionship Under-21 2015 in football, completing data, frequency of game activities, ratio of defensive and offensive game activities of goalkeeper and comparing the effect of regular and irregular performance on the goalkeeper on European Chapmionship Under-21 2015 in Czech republic. Methods: For getting information there were used indirect observation in this Bachelor thesis. The indirect observation from videorecords was time postponed. Results: The results show that in current football the goalkeeper has to be in control of the game with his foot more than ever before. A study points to the fact that the goalkeeper has to offend four times more than defend during the game. Available data show that U21 goalkeepers run less towards center balls than their older colleagues. The data also show that especially defense experience and regular utilization during the game shows. Keywords: Goalkeeper, game activities of goalkeeper, catching ball, rebound ball, running out for centered balls, taking ball, throwing...