65 research outputs found

    Ground reaction force differences in the countermovement jump in girls with different levels of performance

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    Purpose: The aim of this study was to ascertain the biomechanical differences between better and poorer performers of the vertical jump in a homogeneous group of children. Method: Twenty-four girls were divided into low-scoring (LOW; M age = 6.3 ± 0.8 years) and high-scoring (HIGH; M age = 6.6 ± 0.8 years) groups based on their performance on the vertical jump. The force-, velocity-, displacement-, and rate of force development (RFD)-time curves of vertical jumps were analyzed to determine the differences between groups. Results: The analysis of the data showed differences in the pattern of the ensemble mean curves of the HIGH and LOW groups, although the majority of the differences occurred during the eccentric contraction phase of the jump. The differences in the HIGH group with respect to the LOW group were: lower force at the beginning of the movement, higher speed and RFD during the eccentric phase, high force at the beginning of the concentric phase, higher velocity during the concentric phase, and a higher position at takeoff. Conclusion: The results showed that the HIGH group achieved a higher jump height than did the LOW group by increasing the effectiveness of the countermovement and achieving a more advantageous position at takeoff.Centro de Investigación en Rendimiento Físico y Deportiv

    Reliability of Handgrip Strength Test in Basketball Players

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    Handgrip strength is important in basketball as various movements rely on the continuous use of wrist and digits flexor muscles when catching, holding, shooting and throwing the ball. Therefore, the assessment of handgrip strength is used in prepubertal, adolescent and adult basketball players. The reliability of handgrip strength may be influenced by several factors including age. The purpose of this study was to examine the reliability of handgrip strength in basketball players from childhood to adulthood. Male basketball players (n = 90) were assigned into three groups: prepubertal (9.8 +/- 0.7yrs), adolescents (14.4 +/- 0.6yrs), and adults (26.1 +/- 5.6yrs). Each participant performed three maximal isometric contractions on each hand in two occasions, one day apart. Intraclass correlation coefficient (ICC), standard error of measurement (SEM) and 95% limits of agreement (LOA) were calculated. The test-retest reliability was high for both preferred (ICC = 0.94 - 0.98) and non-preferred (ICC = 0.96 - 0.98) hands, without differences in reliability among age-groups. The results showed a significant age-related increase (p < 0.05) in absolute and relative handgrip strength irrespective of hand preference. The present results indicate that maximum handgrip strength can be measured reliably, using the Jamar hand dynamometer, in basketball players from childhood to adulthood

    Reliability of Maximal Handgrip Strength Test in Pre-Pubertal and Pubertal Wrestlers

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    The purpose of this study was to evaluate the intersession and the intrasession reliability of maximal handgrip strength test in young wrestlers. Twenty-seven prepubertal (9.49 +/- 0.96yrs) and twenty-seven pubertal (14.60 +/- 0.50yrs) male wrestlers performed two assessment sessions separated by one day. Both assessments included a testing protocol consisted of three maximal isometric contractions, on both hands using a hydraulic dynamometer (Jamar). The intersession and intrasession reliability was high for both prepubertal and pubertal wrestlers (ICC = 0.87-0.99). The single trial as well as the best of two and three trials of handgrip strength were slightly less reliable (ICC = 0.87-0.94) than the mean of two and three trials in prepubertal (ICC = 0.95-0.97). The present results indicate that maximum handgrip strength can be measured reliably, using the Jamar dynamometer, in young wrestlers. A single trial as well as the two trials can be used as reliable, less-tiring and less time-consuming methods for the evaluation of handgrip strength than the three trials

    Whole body vibration: What is all the fuss about?

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    Whole body vibration (WBV) has been promoted in the market as a new method for exercising, by which 10min are more than enough for the fitness training of busy, modern people. Several companies have been over-stating the positive effects that this type of exercise has on the human body, advertising the general improvement in strength, flexibility and neuromuscular performance granted through it. The question needs to be asked: ‘Does WBV do what it is said to be doing?’. © 2010, MA Healthcare Ltd. All rights reserved

    Living beyond the binary: experiences of shame and violence within the genderqueer community

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    The aim of this chapter is to contribute to the debate on deconstructing the gender binary, toexplore notions of experiencing shame and violence, and also to identify key points of self-concept ingenderqueer people, by running a survey in three different countries: Greece, the UK and the Netherlands.The survey is the first to explore the impact of this gender- binary discourse and the experience of shameand violence within this frame, within the genderaqueer community in a comparative perspective. Thechapter contributes to the debate on perceptions of masculinity and femininity in association with shameand violence, while reconnoitring the role of culture as a driver of these perceptions and how that role leadsto the re-evaluation of the self along with the sense and impact of shame as a relational process with the self and the society. The survey approaches shame and violence, not only in terms of how they are perceived by the genderqueer community, but also of how they are expressed, e.g. in a passive way (directed violence against a person) or active way (person as actor engaging in violent behaviour) in everyday life. The application of different perspectives on confronting the binary, power and shame provides a critical take on the gender-based debate and on the crux of self-concept and identifies breaks with existing thinking and practice that are essential to any reform of gender recognition policy.</p

    Verbal aggression in basketball: Perceived coach use and athlete intrinsic and extrinsic motivation

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    The purpose of this study was to examine how coaches’ verbal aggressiveness, as perceived by the athletes of basketball team sport, is related to athletes’ intrinsic-extrinsic motivation. One hundred eighty basketball athletes completed two questionnaires, during their training sessions. Statistically significant differences were observed in coaches’ verbal aggressiveness (t1,178=3.53, p<.05), intrinsic motivation (t1,177=-6.31, p<.05), identified regulation (t1,178=-8.80, p<.05), external regulation (t1,172=8.56, p<.05) and amotivation (t1,173=8.82, p<.05), between the two genders of the athletes. Correlation analysis revealed that there was a negative significant relationship between coaches’ verbal aggression with intrinsic motivation (r=-.49) and identified regulation (r=.44), but there was a positive significant one with external regulation (r=.46) and amotivation (r=.40). The results of regression analysis revealed that perceived coaches’ verbal aggressiveness could significantly predict the variables of athletes’ intrinsic motivation and external regulation. Findings and implications for coaches’ type of communication are discussed as well as future research suggestions. © 2015, Editura Universitatea din Pitesti. All rights reserved

    Multimedia blogging in physical education: Effects on student knowledge and ICT self-efficacy

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    The main idea behind this study was to explore the educational potential of multimedia blogging for academic disciplines such as Physical Education (PE) that are not heavily based on written discourse and where multiple representations are important in learning. A class blog was utilized as a means for PE students to reflect on and showcase their performances of four specific basketball skills, through creating multimedia posts on these skills and receiving comments from their instructors, peers and an external expert. The effectiveness of multimedia blogging was evaluated, in terms of the acquisition of knowledge of the specific basketball skills and the self-efficacy in Information and Communication Technologies (ICT), as compared to that of an equivalent multimedia website which lacked the blogging component. Students' responses to the blogging activity were also investigated. The sample were 70 undergraduate PE students who were assigned to two groups, one of which used the class blog (Group A, N = 35) and the other one the website (Group B, N = 35), both for 11 weeks. The study followed a pretest/posttest experimental design, taking before and after measurements of each group through written questionnaires. Participation in the blogging activity did have a positive impact on students' ICT self-efficacy, given that Group A students exhibited significant gains in Internet self-efficacy as well as in multimedia processing and blogging self-efficacy, whereas those of Group B did not. Students' responses to the blogging activity were also positive. However, within both groups no significant increase was found in students' knowledge of the basketball skills. The implications of the findings for higher education and future research are discussed. (C) 2011 Elsevier Ltd. All rights reserved
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