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   

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   

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   

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   

Wirkungen von Sport-Event-Sponsoring bei Fußball-Weltmeisterschaften     

Gerd Nufer 《Sportwissenschaft》2008,38(3):303-322

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Effects of muscle-tendon length on joint moment and power during sprint starts   总被引：3，自引：2，他引：1  

Mero A  Kuitunen S  Harland M  Kyröläinen H  Komi PV 《Journal of sports sciences》2006,24(2):165-173

The aim of this study was to examine the effects of muscle-tendon length on joint moment and power during maximal sprint starts. Nine male sprinters performed maximal sprint starts from the blocks that were adjusted either to 40 degrees or 65 degrees to the horizontal. Ground reaction forces were recorded at 833 Hz using a force platform and kinematic data were recorded at 200 Hz with a film camera. Joint moments and powers were analysed using kinematic and kinetic data. Muscle - tendon lengths of the medial gastrocnemius, soleus, vastus medialis, rectus femoris and biceps femoris were calculated from the set position to the end of the first single leg contact. The results indicated that block velocity (the horizontal velocity of centre of mass at the end of the block phase) was greater (P < 0.01) in the 40 degrees than in the 65 degrees block angle condition (3.39 +/- 0.23 vs. 3.30 +/- 0.21 m . s(-1)). Similarly, the initial lengths of the gastrocnemius and soleus of the front leg in the block at the beginning of force production until half way through the block phase were longer (P < 0.001) in the 40 degrees than in the 65 degrees block angle condition. The initial length and the length in the middle of the block phase were also longer in the 40 degrees than in the 65 degrees block angle condition both for both the gastrocnemius (P < 0.01) and soleus (P < 0.01-0.05) of the rear leg. In contrast, the initial lengths of the rectus femoris and vastus medialis of the front leg were longer (P < 0.05) in the 65 degrees than in the 40 degrees block angle condition. All differences gradually disappeared during the later block phase. The peak ankle joint moment (P < 0.01) and power (P < 0.05) during the block phase were greater in the 40 degrees than in the 65 degrees block angle condition for the rear leg. The peak ankle joint moment during the block phase was greater (P < 0.05) in the 40 degrees block angle for the front leg, whereas the peak knee joint moment of the rear leg was greater (P < 0.01) in the 65 degrees block angle condition. The results suggest that the longer initial muscle-tendon lengths of the gastrocnemius and soleus in the block phase at the beginning of force production contribute to the greater peak ankle joint moment and power and consequently the greater block velocity during the sprint start.  相似文献   

Book reviews     

Richard Meister  W. D. Wall  Fritz Bohnsack  B. F. Nel  Helmut Meyer-Bothling  Joseph S. Roucek  F. W. Prins  Hans Möckelmann  H. J. Dallmer 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1961,7(1):112-127

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Das Pädagogische Konzept Maria Montessoris: Die Permanente Diskussion     

Hermann Röhrs 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1979,25(1):21-41

This article emphasises the internal consistency of Maria Montessori's work by identifying her main educational ideas and clarifying the interrelationships between the individual experimental schools and her writings. An elucidation of the vital part played by the anthropological basis of Maria Montessori's work shows that her entire efforts were directed towards illuminating childhood as the foundation of human development. Within this framework her relationship to Rousseau on the one hand, and to educational reform trends on the other is brought out. It is in this connection that her relations with the World Education Fellowship in general and with Decroly in particular find their significance.  相似文献   

Book reviews     

Walter Hahn  Guy Cellerier  Wolfgang Wilhelm  Jindra Kulich  Robert J. Havighurst  Bryan T. Peck  Annegret Körner  Rodney Skager  Renate Nestvogel  J. H. Sislian  John J. Bergen  Peter W. Kahl  Tony Bates 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1978,24(4):523-544

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