Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist     

Johannes Funken  Kai Heinrich  Steffen Willwacher  Ralf Müller  Jonas Böcker  Hiroaki Hobara 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(1):75-87

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.  相似文献   

Comfort assessment of running footwear: Does assessment type affect inter-session reliability?     

Julia Lindorfer  Josef Kröll  Hermann Schwameder 《European Journal of Sport Science》2019,19(2):177-185

Assessing comfort of running footwear reliably is challenging. The purpose of this study was to compare the intra-rater reliability between different assessment types, to calculate intra-individual reliability scores and to evaluate the effect of rater selection based on individual reliability scores on group level reliability. Three assessment types: ranking, Visual Analogue Scale (VAS), and Likert Scale (LS) were provided twice in six separate sessions among 30 participants, who assessed comfort of five shoes after treadmill running. Spearman's rho provided an evaluation of inter-session relative reliability and typical error as a measure of absolute reliability for each assessment type. Ranking (r?=?0.70, 95% confidence interval [CI] 0.61–0.78) yielded the highest relative reliability for overall comfort, followed by VAS (r?=?0.67, 95% CI 0.56–0.75) and LS (r?=?0.63, 95% CI 0.52–0.72), with large-scale overlaps of CIs between assessment types. The same order of assessment types was found for the percentage of reliable raters (r?≥?0.7) with 60% in ranking scale, 47% in VAS and 37% in LS. Forming subgroups corresponding to the intra-individual reliability substantially increased group level reliabilities. Based on measures of relative reliability, an extreme reduction in resolution as provided by the ranking from pairwise comparisons seems to be a valuable tool in footwear comfort assessments if assessment time is of minor importance. No preference can be provided for the two investigated rating scales. Besides the assessment type, a selection of the best raters in additional reliability checks seems to be a prerequisite for further comfort-related studies.  相似文献   

A “Deleterious” Driver: The “First Teacher” Reform in Sweden     

Ian Hardy  Karin Rönnerman 《Scandinavian Journal of Educational Research》2019,63(5):805-818

This article investigates the implementation of the “förstelärare” or “First teacher” reform in Sweden. We draw upon the insights of a superintendent, union official, principal, three First teachers, and two of their colleagues in one school, and recent literature on career development reform. We employ Michael Fullan’s overview of the “right” and “wrong” drivers of educational reform to analyse the extent to which the First Teacher initiative cultivated productive “professional capital.” The research reveals: how broader national policy aims were in clear tension with municipal-wide school development, and school-level development efforts; the perverse effects of a strong focus upon salary on professional conduct; and how an emphasis upon teachers’ roles per se undermined the espoused policy focus on enhancing teaching. The research cautions against the problematic effects of the initiative on more profession-oriented prerogatives, and how more external, “deleterious,” drivers of reform militate against more productive professional capital.  相似文献   

Between Tradition and Change: Hunting as Metaphor and Symbol in State Socialist Hungary     

György Majtényi 《Cultural and Social History》2016,13(2):231-248

Through the historic metaphor of hunting the essay examines the lifestyle of the dominant elites of Hungary between 1945 and 1990 on the basis of archival documents, private records, and oral history interviews. The analysis emphasizes the fact that there were interactions between the old, prewar aristocracy and the new state socialist elites. The co-incidence of lifestyles can be viewed through the lens of social and cultural change: new elements hit against the old, shaping and dissolving old behavioural patterns. The article analyses hunting in the contexts of social differentiation and social grouping. Using semiotics the author shows how, even during the era of state socialism, power and social distinctions were articulated on the level of lifestyles, and transmitted via the social, semiotic function of behaviours, patterns of taste, and forms of interaction. Thus, hunting evolved into a metaphor over time in Hungary: it was not only an indispensable part of the everyday life of the elite, but also became a symbol for belonging to it.  相似文献   

Zeitökonomische Aspekte der Nachfrage nach Vereinsleichtathletik im europäischen Vergleich     

Dr. phil. Jens Flatau  Werner Pitsch  Dirk Bogendörfer  Eike Emrich 《Sportwissenschaft》2009,39(2):110-119

In a joint project involving European association staff and sports scientists, basic structural data were collected on British, Swedish, Spanish and German athletics clubs to be used for analysis of hypotheses concerning conditions of participation in sports clubs, particularly by children and adolescents. The results showed clear differences in organizational level as well as membership and activity structures in comparisons between European countries and within Germany. The findings revealed the differential functions and significance of sports clubs in the context of the respective institutions and cultures.  相似文献   

Attentional focus effects as a function of task difficulty   总被引：1，自引：0，他引：1  

Wulf G  Töllner T  Shea CH 《Research quarterly for exercise and sport》2007,78(3):257-264

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Elite football on artificial turf versus natural grass: movement patterns, technical standards, and player impressions     

Andersson H  Ekblom B  Krustrup P 《Journal of sports sciences》2008,26(2):113-122

The aim of the present study was to examine the movement patterns, ball skills, and the impressions of Swedish elite football players during competitive games on artificial turf and natural grass. Time - motion analyses (36 observations) and technical analyses (16 team observations) were performed and 72 male and 21 female players completed a questionnaire. No differences were observed between artificial turf and natural grass in terms of total distance covered (mean 10.19 km, s = 0.19 vs. 10.33 km, s = 0.23), high-intensity running (1.86 km, s = 0.10 vs. 1.87 km, s = 0.14), number of sprints (21, s = 1 vs. 22, s = 2), standing tackles (10, s = 1 vs. 11, s = 1) or headers per game (8, s = 1 vs. 8, s = 1), whereas there were fewer sliding tackles (P < 0.05) on artificial turf than natural grass (2.1, s = 0.5 vs. 4.3, s = 0.6). There were more short passes (218, s = 14 vs. 167, s = 12) and midfield-to-midfield passes (148, s = 11 vs. 107, s = 8) (both P < 0.05) on artificial turf than natural grass. On a scale of 0-10, where 0 = "better than", 5 = "equal to", and 10 = "worse than", the male players reported a negative overall impression (8.3, s = 0.2), poorer ball control (7.3, s = 0.3), and greater physical effort (7.2, s = 0.2) on artificial turf than natural grass. In conclusion, the running activities and technical standard were similar during games on artificial turf and natural grass. However, fewer sliding tackles and more short passes were performed during games on artificial turf. The observed change in playing style could partly explain the male players' negative impression of artificial turf.  相似文献   

Examining coaches’ perceptions of how their stress influences the coach–athlete relationship     

Richard C. Thelwell  Christopher R. D. Wagstaff  Michael T. Chapman  Göran Kenttä 《Journal of sports sciences》2017,35(19):1928-1939

This study extends recent coach stress research by evaluating how coaches perceive their stress experiences to affect athletes, and the broader coach–athlete relationship. A total of 12 coaches working across a range of team sports at the elite level took part in semi-structured interviews to investigate the 3 study aims: how they perceive athletes to detect signals of coach stress; how they perceive their stress experiences to affect athletes; and, how effective they perceive themselves to be when experiencing stress. Following content analysis, data suggested that coaches perceived athletes able to detect when they were experiencing stress typically via communication, behavioural, and stylistic cues. Although coaches perceived their stress to have some positive effects on athletes, the overwhelming effects were negative and affected “performance and development”, “psychological and emotional”, and “behavioural and interaction” factors. Coaches also perceived themselves to be less effective when stressed, and this was reflected in their perceptions of competence, self-awareness, and coaching quality. An impactful finding is that coaches are aware of how a range of stress responses are expressed by themselves, and to how they affect athletes, and their coaching quality. Altogether, findings support the emerging view that coach stress affects their own, and athlete performance.  相似文献   

Intercultural education in physical education: results of a quasi-experimental intervention study with secondary school students     

Elke Grimminger-Seidensticker  Aiko Möhwald 《Physical Education & Sport Pedagogy》2017,22(5):445-458

Background: Due to migration processes, cultural diversity and strangeness are becoming characteristics of modern society. The competence to handle this heterogeneity – the so-called intercultural competence – is a key competence for all children and youths. Sports and physical education (PE) are often considered as a particular field for enhancing intercultural competence. However, until now there is no theory-based empirical study that proves this assumption. Purpose: This study was designed to examine the effects of a standardised, theoretically driven programme in PE on the development of underlying cognitive concepts of intercultural competence: acculturation attitudes and attitudes towards cultural diversity. Research design: The research design consists of a quasi-experimental design with four measurement points. The intervention group (N?=?69; mean age?=?11.6 years (SD?=?0.60)) followed standardised and theory-driven intervention lessons following the didactical guidelines of the concept of ‘Intercultural Movement Education’ (IME). The developed games tend to trigger ‘crises’ with the aim to insecure students. These experienced insecurities were afterwards reflected upon with the students. The internal control group (N?=?63; mean age?=?11.8 years (SD?=?0.62)) and external control group (N?=?93; mean age?=?10.8 years (SD?=?0.69)) were taught in a unspecific manner. The impact of the intervention study programme was tested with a reliable and valid questionnaire. Results: A significant time by group interaction effect for the subscale ‘assimilation/segregation’ of acculturation attitudes was found in boys and in girls. The attitudes increased significantly after the intervention. For the girls, the intervention group showed also a significant decrease of the attitude ‘integration’. No significant impact of the intervention study on the attitudes towards cultural diversity could be identified either with boys or girls. Discussion: The effects of the study are ambivalent. The significantly increased assimilative attitudes can be interpreted as a need for a sense of security. This is also underlined by the decrease of the integration attitude that values the maintenance of cultural integrity. It must be critically discussed whether the ‘crises’ were too intense and not adapted to the children’s skills to overcome them. Second, we have to critically analyse whether the discussions with the students about their experiences were sufficiently focused to debrief the students. Summary for practitioners: The competence to handle heterogeneity – the so-called intercultural competence – is a key competence for children and youths. Sports and PE are often considered as a particular field for enhancing intercultural competence. However, until now there has been no theory-based empirical study that proves this assumption. This paper describes the development, implementation and evaluation of an intervention programme on intercultural learning in PE along the didactic guidelines of IME. This programme tries to trigger ‘crises’ that stimulate the students to react and think about their self- and world relations. The statistical analyses show that the ‘crises’ were probably too intense as the students’ scores in assimilation attitudes increased. This lead to the didactical reflection of the implementation of intercultural learning processes in PE.  相似文献   

Sport disciplines,types of sports,and waist circumference in young adulthood – a population-based twin study     

Mirva Rottensteiner  Sara Mäkelä  Leonie H. Bogl  Timo Törmäkangas  Jaakko Kaprio  Urho M. Kujala 《European Journal of Sport Science》2017,17(9):1184-1193

Purpose: The benefits of physical activity (PA) in preventing abdominal obesity are well recognized, but the role of different sport disciplines remains open. We aimed, therefore, to investigate how participation in different sport disciplines, and the number and types of sports engaged in are associated with waist circumference (WC) in young adulthood. Methods: This population-based cohort study comprised 4027 Finnish twin individuals (1874 men), with a mean age of 34 y (32–37), who answered a survey, including self-measured WC. We extracted the number and identified the types (aerobic, power, and mixed) of the different sport disciplines respondents reported participating in. Results: The number of sport disciplines participated in was inversely associated with WC, the linear decrease averaging 1.38?cm (95% CI 1.10–1.65) per each additional sport discipline. The result persisted after adjustment for the main covariates, such as volume of PA and diet quality. Among dizygotic twin pairs discordant for sports participation (0–2 vs. 5 or more disciplines), the mean within-pair difference in WC was 4.8?cm (95% CI 0.4–9.1) for men and 11.2?cm (95% CI 4.4–18.0) for women; among discordant monozygotic pairs, no differences were observed. In men, all three types of sports were individually associated with smaller WC, while in women, only mixed and power sports showed this association. Conclusions: Participation in several sport disciplines and sport types was associated with smaller WC among young adults in their mid-30s. Shared genetic background may explain some of the associations.  相似文献