Changes in kinematics and arm–leg coordination during a 100-m breaststroke swim

The purpose of this study was to compare arm–leg coordination and kinematics during 100 m breaststroke in 26 (8 female; 18 male) specialist breaststroke swimmers. Laps were recorded using three 50-Hz underwater cameras. Heart rate and blood lactate were measured pre- and post-swim. Arm–leg coordination was defined using coordination phases describing continuity between recovery and propulsive phases of upper and lower limbs: coordination phase 1 (time between end of leg kick and start of the arm pull phases); and coordination phase 2 (time between end of arm pull and start of leg kick phases). Duration of stroke phases, coordination phases, swim velocity, stroke length (SL), stroke rate (SR) and stroke index (SI) were analysed during the last three strokes of each lap that were unaffected by turning or finishing. Significant changes in velocity, SI and SL (P < 0.05) were found between laps. Both sexes showed significant increase (P < 0.05) in heart rate and blood lactate pre- to post-swim. Males had significantly (P < 0.01) faster swim velocities resulting from longer SLs (P = 0.016) with no difference in SR (P = 0.064). Sex differences in kinematic parameters can be explained by anthropometric differences providing males with increased propelling efficiency.     

Age and sex influences on running mechanics and coordination variability

The purpose of this study was to examine the impact of age on running mechanics separately for male and female runners and to quantify sex differences in running mechanics and coordination variability for older runners. Kinematics and kinetics were captured for 20 younger (10 male) and 20 older (10 male) adults running overground at 3.5 m · s^?1. A modified vector coding technique was used to calculate segment coordination variability. Lower extremity joint angles, moments and segment coordination variability were compared between age and sex groups. Significant sex–age interaction effects were found for heel-strike hip flexion and ankle in/eversion angles and peak ankle dorsiflexion angle. In older adults, mid-stance knee flexion angle, ankle inversion and abduction moments and hip abduction and external rotation moments differed by sex. Older compared with younger females had reduced coordination variability in the thigh–shank transverse plane couple but greater coordination variability for the shank rotation–foot eversion couple in early stance. These results suggest there may be a non-equivalent aging process in the movement mechanics for males and females. The age and sex differences in running mechanics and coordination variability highlight the need for sex-based analyses for future studies examining injury risk with age.     

Tilting at Windmills

No abstract available for this article.     

高校图书馆现刊管理存在的问题及对策

高校图书馆读者群集中,教学、科研、学习等对现刊需求的及时性与可获得性更是不可忽视。文章对高校图书馆现刊从订购到装订的全程进行了梳理,指出存在的问题,并针对性地提出科学实用的对策。     

澳门学生的体脂率以及与部分运动素质项目的相关研究

通过对澳门青少年的体质调查和统计分析,得出澳门青少年的体脂率均数、年龄变化及性别差异;得出澳门青少年相邻年龄组体脂率均数差别的检验结果、体指率分布的正态性检验结果、体脂率与部分运动素质项目相关分析的结果,为体育教育和健康辅导等提供依据性资料。     

试论中老年人股骨颈骨折的防治与体育康复

中老年人应及早防治“骨质疏松症”。通过加强自我防治意识;及时补充微量元素和食用含钙量高的食物。坚持体育运动,提高钙的利用率以防患于未然。一旦发生股骨颈骨折,应采用中,西医结合,服用药物与体育医疗相结合,使其早日康复,达到“老能自养”,“老有所乐”。     

青春发育突增期不同发育类型学生的性发育、性教育状况及其干预

对北京市海淀区五所中学中1987年9月至1988年8月出生的男生457和三所小学中1989年9月至1990年8月出生的女生450人拍摄了X射线骨龄片,并请专家按CHN法对每张骨龄片进行了判别,从中筛选出了男、女生早发育组、正常发育组、晚发育组每组30人,共计180人作为实验对象,对实验对象的第二性征进行了测试并对其性知识和态度等进行了问卷调查,较好的了解了目前青春发育突增期三种发育类型学生的性发育状况及其对性知识和性教育的态度,较深入地分析了目前我国性教育中存在的问题,为今后更好的对青春发育期的学生进行性教育提供了理论依据.     

心灵的挣扎与突围——读东西的长篇小说《后悔录》

东西的长篇小说《后悔录》从中国人共有的后悔心理这一角度来构架作品，以“性”作为中心话题进行故事的铺陈与叙写，目的在于控诉那段荒诞的历史：给生活在其中的人们带来无法愈合的心灵创伤，以及为之挣扎与突围的痛苦。     

青少年生长激素分泌水平的研究进展

生长激素是控制人体生长发育最重要的激素。生长激素缺乏是导致青 少年身材矮小的主要原因之一。就近年来国内外有关青少年生长激素水平的研究 进展进行综述,探讨青少年生长激素分泌变化的一般规律及其影响因素,指出生长 激素在生理条件下,主要受睡眠、药物、运动等因素的影响,并针对影响因素的改 变而增加青少年生长激素分泌这一问题进行分析,提出运动是一种理想的调节身 体GH分泌的手段。另外,许多文献均指出运动强度、运动时间、运动方式等诸方 面,对GH的分泌有影响,但对此均无统一明确的论断,有待于进一步研究。并且针 对不同的年龄、不同的性别、不同的体质等,如何综合运用这些运动手段来调节 GH的分泌、促进身体生长,也是我们应该深入探讨的课题。     

Gender Verifications in Sport: From an East/West Antagonism to a North/South Antagonism

This paper aims to analyze gender verifications in sport from a socio-historical approach. These medical controls intended to keep men from competing in women's international competitions. Some female athletes are put through a masculinization trial, because of morphologies and performances judged as too masculine. Facing these athletes who disrupt the representation of a binary construction between the male sex and the female sex, sports institutions attempt to maintain a sexual bi-categorization. More precisely, this paper will present the ‘symbolic’ suppression of tests since 2000. Thereafter, authorities only rely on an aesthetic and visual assessment of female bodies and no longer use tests in a systematic and obligatory fashion. This reveals the moving boundary subjectively plotted between the masculine and the feminine, which become all the more blurred when the ‘race and class markers’ interfere with the ‘sex markers’.