994 resultados para movement organisation
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The influence of different instructional constraints on movement organisation and performance outcomes of the penalty kick (PK) was investigated according to participant age. Sixty penalty takers and twelve goalkeepers from two age groups (under 15 and under 17) performed 300 PKs under five different task conditions, including: no explicit instructional constraints provided (Control); instructional constraints on immobility (IMMOBILE) and mobility (MOBILE) of goalkeepers; and, use of keeper-dependent (DEP) and independent (INDEP) strategies by penalty takers. Every trial was video recorded and digitised using motion analysis techniques. Dependent variables (DVs) were: movement speed of penalty takers and the angles between the goalkeeper's position and the goal line (i.e., diving angle), and between the penalty taker and a line crossing the penalty spot and the centre of the goal (i.e., run up angle). Instructions significantly influenced the way that goalkeepers (higher values in MOBILE relative to Control) and penalty takers (higher values in Control than in DEP) used movement speed during performance, as well as the goalkeepers' movements and diving angle (less pronounced dives in the MOBILE condition compared with INDEP). Results showed how different instructions constrained participant movements during performance, although players' performance efficacy remained constant, reflecting their adaptive variability.
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This book examines international labour movement opposition to globalisation. It chronicles and critically scrutinizes the emergence of distinctively new forms of labour movement organisation and mobilisation that constitute creative initiatives on the part of labour, which present capitalism with fresh challenges.
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Russell, Benton and Kingsley (2010) recently suggested a new association football test comprising three different tasks for the evaluation of players' passing, dribbling and shooting skills. Their stated intention was to enhance ‘ecological validity’ of current association football skills tests allowing generalisation of results from the new protocols to performance constraints that were ‘representative’ of experiences during competitive game situations. However, in this comment we raise some concerns with their use of the term ‘ecological validity’ to allude to aspects of ‘representative task design’. We propose that in their paper the authors confused understanding of environmental properties, performance achievement and generalisability of the test and its outcomes. Here, we argue that the tests designed by Russell and colleagues did not include critical sources of environmental information, such as the active role of opponents, which players typically use to organise their actions during performance. Static tasks which are not representative of the competitive performance environment may lead to different emerging patterns of movement organisation and performance outcomes, failing to effectively evaluate skills performance in sport.
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The overarching aim of this thesis was to investigate how processes of perception and action emerge under changing informational constraints during performance of multi-articular interceptive actions. Interceptive actions provide unique opportunities to study processes of perception and action in dynamic performance environments. The movement model used to exemplify the functionally coupled relationship between perception and action, from an ecological dynamics perspective, was cricket batting. Ecological dynamics conceptualises the human body as a complex system composed of many interacting sub-systems, and perceptual and motor system degrees of freedom, which leads to the emergence of patterns of behaviour under changing task constraints during performance. The series of studies reported in the Chapters of this doctoral thesis contributed to understanding of human behaviour by providing evidence of key properties of complex systems in human movement systems including self-organisation under constraints and meta-stability. Specifically, the studies: i) demonstrated how movement organisation (action) and visual strategies (perception) of dynamic human behaviour are constrained by changing ecological (especially informational) task constraints; (ii) provided evidence for the importance of representative design in experiments on perception and action; and iii), provided a principled theoretical framework to guide learning design in acquisition of skill in interceptive actions like cricket batting.
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Objectives: Adaptive patterning of human movement is context specific and dependent on interacting constraints of the performer–environment relationship. Flexibility of skilled behaviour is predicated on the capacity of performers to move between different states of movement organisation to satisfy dynamic task constraints, previously demonstrated in studies of visual perception, bimanual coordination, and an interceptive combat task. Metastability is a movement system property that helps performers to remain in a state of relative coordination with their performance environments, poised between multiple co-existing states (stable and distinct movement patterns or responses). The aim of this study was to examine whether metastability could be exploited in externally paced interceptive actions in fast ball sports, such as cricket. Design: Here we report data on metastability in performance of multi-articular hitting actions by skilled junior cricket batters (n = 5). Methods: Participants’ batting actions (key movement timings and performance outcomes) were analysed in four distinct performance regions varied by ball pitching (bounce) location. Results: Results demonstrated that, at a pre-determined distance to the ball, participants were forced into a meta-stable region of performance where rich and varied patterns of functional movement behaviours emerged. Participants adapted the organisation of responses, resulting in higher levels of variability in movement timing in this performance region, without detrimental effects on the quality of interceptive performance outcomes. Conclusions: Findings provide evidence for the emergence of metastability in a dynamic interceptive action in cricket batting. Flexibility and diversity of movement responses were optimised using experiential knowledge and careful manipulation of key task constraints of the specific sport context.
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Newell (1985, 1986) identified the importance of interacting constraints on the emergent behaviours of learners or performers in sport as they assemble functional states of movement organisation in achieving task goals. Constraints, related to the person, task and environment, were defined as ‘boundaries or features that limit motion of the entity under consideration at any moment in time’ (Newell, 1986, p.347). Personal (or organismic) constraints include factors such as individual anthropometrics (height, weight, and limb lengths), fitness (e.g., strength, speed, aerobic capacity, and flexibility), mental skills (e.g. concentration, confidence, emotional control and motivation), perceptual and decisionmaking skills (e.g., recognising patterns of play, anticipation by reading the movements of opponents) and personality factors (e.g., risk taking or conservative behaviours). Newell (1986, p.350) distinguished between general environmental constraints, such as gravity, ambient temperature, natural light and altitude and task constraints, which are task specific and concerned with the goals of a specific activity. More recently, socio-cultural constraints (e.g., family support, cultural expectations and access to facilities) have also been considered as environmental constraints. Application of the constraints framework to the study of sport performance has led to task constraints being defined to include factors such as rules of games, equipment used, boundary playing areas and markings, nets and goals, the number of...
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Why should a progressive planner/urbanist pay attention to the Spanish 15M movement? From a disciplinary standpoint, its most complex and interesting aspect, which could hypothetically be transferred to other contexts (as in fact happened in the Occupy Wall Street and Occupy London movements), is its 'spatiality'. This article analyses the spatial practices of the so called #spanishrevolution, one of the 2011 social movements that showed the possibility for a new collective appropriation and self-management (autogestion) of urban public space. Although the political goals of the movement were vague at the time of its inception, the practices and spatial imaginaries deployed by it have become consolidated and proven to be yet another of its more successful facets in promoting the spreading and organisation of the protest, making it a phenomenon that calls for reflection on the part of urban thinkers and planners.
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This chapter elucidates key ideas behind neurocomputational and ecological dynamics and perspectives of understanding the organisation of action in complex neurobiological systems. The need to study the close link between neurobiological systems and their environments (particularly their sensory and movement subsystems and the surrounding energy sources) is advocated. It is proposed how degeneracy in complex neurobiological systems provides the basis for functional variability in organisation of action. In such systems processes of cognition and action facilitate the specific interactions of each performer with particular task and environmental constraints.
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How the CNS deals with the issue of motor redundancy remains a central question for motor control research. Here we investigate the means by which neuromuscular and biomechanical factors interact to resolve motor redundancy in rhythmic multijoint arm movements. We used a two-df motorised robot arm to manipulate the dynamics of rhythmic flexion-extension (FE) and supination-pronation (SP) movements at the elbow-joint complex. Participants were required to produce rhythmic FE and SP movements, either in isolation, or in combination (at the phase relationship of their choice), while we recorded the activity of key bi-functional muscles. When performed in combination, most participants spontaneously produced an in-phase pattern of coordination in which flexion is synchronised with supination. The activity of the Biceps Brachii (BB), the strongest arm muscle which also has the largest moment arms in both flexion and supination was significantly higher for FE and SP performed in combination than in isolation, suggesting optimal exploitation of the mechanical advantage of this muscle. In a separate condition, participants were required to produce a rhythmic SP movement while a rhythmic FE movement was imposed by the motorised robot. Simulations based upon a musculoskeletal model of the arm demonstrated that in this context, the most efficient use of the force-velocity relationship of BB requires that an anti-phase pattern of coordination (flexion synchronized with pronation) be produced. In practice, the participants maintained the in-phase behavior, and BB activity was higher than for SP performed in isolation. This finding suggests that the neural organisation underlying the exploitation of bifunctional muscle properties, in the natural context, constrains the system to maintain the
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North Italy's nomadic shepherds are a phenomenon unique in the world. Their nomadic nature is taken to the extreme since they move constantly rather than solely in the winter or the summer, as in the usual nomadism. Their home is on wheels and their territory is the tightly regulated yet sprawling Triveneto area. The Triveneto transhumance moves beyond private/public property divides, and indeed beyond lawful/unlawful distinctions, giving rise to what I have called an animal normativity. Relying on Valentina De Marchi's text 'Fame d'Erba' on the Triveneto transhumance, I show how territory becomes a question of animal hunger, and movement becomes an atmospheric, silent and imperceptible affect that crosses private property boundaries, state law limitations, reservation areas and road networks. This way of being, beyond the usual distinctions, offers an example of an alternative political and legal organisation that brings forth the continuum between the human, the natural and the legal/political.
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Ce mémoire tente d’identifier la nature du lien entre les stratégies d’organisation syndicale et le résultat des campagnes de syndicalisation. À l’aide d’une étude du cas des campagnes d’organisation menées par les Travailleurs et travailleuses unis de l’alimentation et du commerce (TUAC) chez Wal-Mart au Québec, nous avons examiné l’impact que peuvent avoir différentes variables sur le succès d’une campagne. La littérature sur le renouveau syndical nous a permis d’identifier trois types de campagnes, soit la campagne traditionnelle, la campagne intégrale et la campagne de mouvement social, et nous a amenés à postuler que le type de campagne privilégié aura un effet sur l’impact de la campagne. Nos résultats nous permettent d’arriver à trois conclusions. Premièrement, nous notons deux tactiques relevant de la campagne traditionnelle ayant eu un impact positif sur le résultat des campagnes : l’utilisation de la technique du blitz et le recrutement de poteaux solides. Deuxièmement, le degré d’opposition patronale à la syndicalisation semble avoir un impact sur le degré de succès d’une campagne. Troisièmement, l’analyse des résultats nous permet de constater l’impact significatif du cadre juridique. L’un des éléments les plus importants est l’accréditation par décompte des adhésions comparativement à l’accréditation suite à un vote.
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À travers le cas de la Coalition québécoise contre la réforme de l’assurance-emploi, nous cherchons à comprendre quels sont les facteurs qui influencent les dynamiques internes d’une coalition de mouvements sociaux. Pour ce faire, nous effectuons, tout d’abord, une revue de la littérature axée sur les théories des mouvements sociaux et les coalitions de mouvements sociaux. Celle-ci nous permet de formuler l’hypothèse selon laquelle les relations interpersonnelles entre les représentants des différents groupes sociaux membres d’une coalition vont influencer sa durabilité et l’accomplissement de ses objectifs. Nous testons ensuite cette hypothèse en passant les données recueillies au filtre des indicateurs élaborés au sein de notre cadre théorique. Il s’agit donc de voir en quoi la structure de prise de décisions (processus décisionnel participatif et égalitaire, construction du plan d’action conjoint et élaboration des critères d’adhésion) et la présence de liens interpersonnels, préexistants à la formation de la Coalition, entre les individus membres de celle-ci, ont une influence sur son fonctionnement et sa continuité dans le temps. Enfin, nous terminons en analysant les liens personnels entre ces individus à travers l’ambiance dans les rencontres, le plaisir d’y participer et les relations qui s’y sont développées.
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During the second half of the nineteenth century fraternal and benevolent associations of numerous descriptions grew and prospered in mining communities everywhere. They played an important, but neglected role, in assisting transatlantic migration and movement between mining districts as well as building social capital within emerging mining communities. They helped to build bridges between different ethnic communities, provided conduits between labour and management, and networked miners into the non-mining community. Their influence spread beyond the adult males that made up most of their membership to their wives and families and provided levels of social and economic support otherwise unobtainable at that time. Of course, the influence of these organisations could also be divisive where certain groups or religions were excluded and they may have worked to exacerbate, as much as ameliorate, the problems of community development. This paper will examine some of these issues by looking particularly at the role of Freemasonry and Oddfellowry in Cornwall, Calumet, and Nevada City between 1860 and 1900. Work on fraternity in the Keweenaw was undertaken in Houghton some years ago with a grant from the Copper Country Archive and has since been continued by privately funded research in California and other Western mining states. Some British aspects of this research can be found in my article on mining industrial relations in Labour History Review April 2006
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Includes bibliographical references.
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This thesis examines relations between the French Confederation Generale du Travail (CGT) and the labour movements of other countries in the years leading up to the First World War. The aim of the study is to examine the CGT's policy of internationalism in practice, both in relations with other labour movements and in its membership of the International Secretariat of National Trade Union Centres (between 1900 and 1914). In particular, the relationship between the French and German labour movements is explored in the light of the events of August 1914. This study shows that the relationship was a reflection of the respective positions of the French and German labour movements in the international movement. It also subjects to close scrutiny the assumption, widely made before 1914, that workers had more in common with each other than with the ruling classes of their own country, by analysing the extent of, and the reasons for internationalism and international cooperation in the labour movement. As a study of the International Secretariat of National Trade Union Centres, an organisation about which very little has previously been written, this thesis complements existing work on the international labour movement prior to 1914. It also provides new insights into the French CGT by concentrating on the fundamental areas of internationalism and opposition to war, and offers fresh contributions to the continuing debate on the international labour movement and its response to the outbreak of war.