Utilization of cues in action anticipation in table tennis players

ABSTRACT

By manipulating the congruency between body kinematics and subsequent ball trajectory, this study investigated the anticipation capabilities of regional-level, college-level, and novice table tennis players using a full video simulation occluder paradigm. Participants watched footage containing congruent, incongruent, or no ball trajectory information, to predict the landing point of the ball. They were required to choose between two potential locations to make their prediction. Percent accuracy and relevant indexes (d-prime, criterion, effect size) were calculated for each condition. Results indicated that experienced table tennis players (both regional and college players) were superior to novices in the ability to anticipate ball trajectory using kinematic information, but no difference was found between regional-level and college-level players. The findings of this study further demonstrate the superior anticipation ability of experienced table tennis players. Furthermore, the present result suggests that there may be a certain “baseline” level of motor experience in racquet sports for effective action anticipation, while the addition of further motor experience does not appear to assist direction anticipation.     

Effect of a randomised 12-week resistance training programme on muscular strength,cross-sectional area and muscle quality in women having undergone Roux-en-Y gastric bypass

The purpose of this study was to examine the effect of a 12-week resistance training programme on fat-free mass (FFM), muscle cross-sectional area, muscular strength and muscle quality in women who underwent Roux-en-Y gastric bypass surgery. Participants were 16 women (mean age = 44.9 ± 10.2 years) from bariatric surgical groups who were randomly assigned into either a control or an intervention group. Air displacement plethysmography measured FFM and magnetic resonance imaging measured quadriceps muscle cross-sectional area and whole thigh muscle cross-sectional area. Muscular strength and quality was assessed using an estimated 1-Repetition Maximum assessment. All measurements were collected twice, at baseline and at a 12-week follow-up. There were significantly greater improvements in leg press strength (mean differences = 55.4%, P < 0.001, Cohen’s d = 2.4), leg extension strength (mean differences = 18.0%, P = 0.014, Cohen’s d = 0.86) and leg press muscle quality (mean differences = 54.5%, P < 0.001, Cohen’s d = 1.9) in the intervention group compared to the control group following the resistance training programme. The resistance training intervention significantly improved muscular strength and quality; however, it did not illicit changes in FFM or muscle cross-sectional area in women who underwent Roux-en-Y gastric bypass surgery.     

Book reviews

Thigh muscle volume is a useful determinant of functional fitness. However, anthropometric prediction of muscle content is influenced by the variability of adipose tissue accumulation. The aims of this study were to predict thigh muscle and adipose tissue volumes from anthropometry and to assess the validity of the method by examining the various components of the measurements and the assumptions involved. The 19 participants (9 men, 10 women; age 23-49 years) varied in adiposity. They all underwent magnetic resonance imaging (MRI) of the upper leg and the eight men and two women with the lowest adiposity underwent detailed anthropometry involving girths and skinfolds. Using MRI as the reference method, muscle volume was predicted from anthropometry using a circular concentric model, and the assumptions inherent in the method were tested further using the MRI data alone. Muscle volume was best predicted by anthropometry in the 10 leanest participants using a five-slice truncated cone model that overestimated the mean MRI value by 30% ( R 2 = 0.95; standard error of estimate = 288 cm 3 ; P ? 0.001). A single skinfold plus girth measurement at the mid-thigh almost matched its predictive ability, but with an increased bias. Measurements of leg circumference by means of the two techniques agreed well. The assumption of a circular cross-section was valid. In contrast, the agreement between skinfold thickness measured by caliper and superficial adipose tissue thickness by MRI was poor, contributing to the scatter of fat and lean area comparisons. An anterior skinfold thickness measurement underestimated the area of superficial adipose tissue at that level, particularly at the most proximal and distal sites. Although these limitations increase the uncertainties of muscle volume determination by anthropometry, they do not prevent its valid prediction in leaner individuals. The prediction of superficial adipose tissue was poorer.     

On the role of imagery modalities on motor learning

Abstract

In the present study, we examine specifically how the sensory conditions available during physical practice of a task might influence the subsequent use of motor imagery. First, as a pre-test, participants had to physically reproduce knee joint positions with or without vision. Second, they practised motor imagery (15 and 150 trials) with visual, kinaesthetic or visuo-kinaesthetic imagery. A control group with no imagery was included. Post-tests were then performed 10 min and 24 h after each imagery session in a sensory condition similar to that used in the pre-test. Results showed that efficient motor imagery instructions have to take account of the sensory information available during physical experience of the task: kinaesthetic or visuo-kinaesthetic imagery in a no-vision condition, and visual imagery or, to a lesser extent, visuo-kinaesthetic imagery in a vision condition. Discussion focuses on the role of sensory motor memory on motor prediction to simulate a specific movement, and on the similarities between physical and mental practice in the development of sensory-specific movement representation.     

网球大满贯单打运动员身体形态及相关年龄特征分析

为了对网球大满贯单打运动员的身体形态以及运动生涯中相关年龄特征有一个清楚的了解,以期对以后从事网球运动的运动员的选材、训练以及运动生涯的宏观把握提供理论及数据参考,运用文献资料、数理统计法等对其身体形态指标以及运动生涯中相关年龄特征分析后得知,网球大满贯单打男子和女子球员的身高、体重、克菜托指数三项指标都具有稳定的正态分布特征;男子和女子球员在学球年龄和首获大满贯年龄上不存在显著性差异（P〉0．05）;在转入职业赛年龄和首获职业赛冠军年龄上却存在显著性差异（P〈0．05）;而在职业生涯冠军总数及职业年限上不存在显著性差异（P〉0．05）。     

Future Girls,transcendent femininities and new pedagogies: toward girls' hybrid bodies?

Media provides a material site for girls' identity formation and presents conflicting images of femininity, which challenge young women's self-expression and physicality development. The ‘problem’ with girls' physicality has not been resolved, but rather complicated by discourses of new femininities in sport, fitness and health promoted by the new economies. Girls' conscious and unconscious consumption of messages of new powerful femininities might be troubling for some girls, especially ‘Other’ girls and/or girls ‘at risk,’ whose physicality collides with the emerging image of the new girls. Therefore, in this paper, I contend that an investment in the third-wave feminist agenda is still necessary to engage scholars, educators and girls in critical conversations about media, genders, the body and identity. To this end, first I discuss the feminist reappraisal of Foucault's analysis of the body as an emancipatory socio-educational and political project for (en)gendering research on the feminine ‘docile body’ in society. Second, I highlight emerging contemporary monocultural discourses of the ‘Alpha Girl’ and the ‘Future Girl,’ powerful sporty, fit and healthy femininities that contradict discourses of the traditional feminine docile body, and I analyze the ways these new images subsume race, class, religion and disability. Finally, I conclude this article by advocating the adoption of critical media pedagogies as a potential strategy for schooling girls' hybrid bodies.     

A Consideration of Why Active Participation in Sport and Leisure Might Reduce Criminal Behaviour

This paper contributes to sport, sociology and the body literature by exploring the ‘exposure and effect’ of culture, in particular bodily practices placed on three adolescent swimmers immersed in the Australian swimming culture using an ethnographic framework. The research reported is particularly notable as it addresses two distinct time points in the swimmers’ lives. The first section explores the adolescent experiences of three female swimmers within the cultural context of Australian swimming by articulating some of the specific body practices and ‘memes’ (ideas, symbols and practices) that they were exposed to and/or engaged within relation to the body. The second section of this paper focuses on the same three swimmers in the ‘present day’, some 10–30 years after being immersed in the Australian swimming culture as adolescents. It excavates their body practices and the relationships they now have with their body, and thus pursues the sustained impact of the body practices and ‘memes’ they were exposed to as adolescents. Analysis employs concepts drawn mainly from Foucault, particularly his thesis in regard to ‘disciplinary power’, ‘regulation’ ‘classification’ and ‘surveillance’. At a club (amateur) and National level, Australian swimming is revealed as an institution, a site and culture where particular techniques of power have become concentrated and have been brought to bear on individuals in systematic ways, with sometimes damaging effects arising for athletes’ long-term health and well-being, particularly if the individuals concerned continue to engage with cultural practices in regard to the body post-career.     

Circles with a suspended aid: reducing pommel reaction forces

The aim of this study was to investigate the influence of a suspended aid on the reaction forces during a basic skill on pommel horse. Twenty gymnasts performed three sets of 10 circles with and without a suspended aid on a pommel horse under which two force plates were set. The results confirmed that the suspended aid could reduce the magnitude of the pommel reaction forces during circles while maintaining the general loading pattern. On the left hand, the average and peak forces were attenuated to 0.59 body weight (BW) and 0.85 BW from 0.76 BW and 1.13 BW, respectively. The right hand experienced slightly larger forces with no-aid trials, but the asymmetry between the hands decreased with the aid. Despite a relatively large variability, all gymnasts experienced smaller impact peak forces with the aid. A suspended aid is most commonly used for a beginner gymnast as an introduction to pommel horse exercises. However, this study confirmed that it can also be useful for all levels of gymnasts who would like to practice pommel horse exercises with reduced pommel reaction forces for a purpose such as a progression for learning a new skill, control of training volume, or rehabilitation.     

论高等学校的法律性质和法律地位

高等学校是我国事业单位法人,属于法律法规授权行使部分行政职能的授权组织,具有行政主体、行政相对人、民事主体三重身份。正确界定高等学校的法律性质和法律地位,有助于加强对高等学校的管理和监督,规范高等学校的管理行为和服务行为,为行政相对人提供法律救济,构建和谐校园,促进校园管理法治化。