中国女子排球运动员后备力量相关指标剖析

调研以提高中国女子排球运动竞技水平为目的,以选拔、培养国家女排后备力量为组织核心的数届全国青年女排集训比赛的运动员为主要研究对象,采用文献资料、数理统计等方法,对其身体形态和专项身体素质数据进行分析。研究认为：近三年来全国青年女子排球运动员的年龄征象、身高水平相对稳定;主攻、副攻、二传、接应的体重、指高差异不显著、专位特色不鲜明;助跑摸高、6m×16次移动水平停滞不前;下肢垂直与水平爆发力等专项素质亟待提高;相关指标数据与国家女排运动员、甲A女排运动员有较大差距;身材高大的运动员仍较缺乏。     

简论推动现代排球运动发展的主要动力

本文对排球运动发展的历史过程进行分析、探讨,并从哲学角度运用自然辩证法进行论证,发现以寻求攻防平衡为目的的规则改变不断地改进和完善排球运动,使排球运动更加激烈、精彩;另外不同时期人们对排球各种功能的需求也有效地推动了排球运动的发展。它们是推动排球运动发展的主要因素。更好地把握和利用排球运动发展的动因能更好地促进排球运动的发展。     

Predicting ground reaction forces in running using micro-sensors and neural networks

Measurement of ground reaction force (GRF) in running provides a direct indication of the loads to which the body is subjected at each foot-ground contact, and can provide an objective explanation for performance outcomes. Traditionally, the collection of three orthogonal component GRF data in running requires an athlete to complete a series of return loops along a laboratory based runway, within which a force platform is embedded, in order to collect data from a discrete footfall. The major disadvantages associated with this GRF data collection methodology include the inability to assess multiple consecutive foot contacts and the fact that measurements are typically confined to the laboratory. The objective of this research was to investigate the potential for wearable instrumentation to be employed, in conjunction with artificial neural network (ANN) and multiple linear regression (MLR) models, for the estimation of GRF in middle distance running. A modular wearable data acquisition system was developed to acquire in-shoe force (ISF) data. Matched data sets from wearable instrumentation (source data) and force plate (target data) records were collected from elite middle-distance runners under controlled laboratory conditions for the purposes of ANN and MLR model development (MD) and model validation (MV). In terms of statistical measures of prediction accuracy the MLR model was found to provide a superior level of accuracy for the prediction of the vertical and medio-lateral components of GRF and alternatively, the ANN model provided the most accurate predictions of the anterior-posterior component of GRF. The prediction accuracy of each component of GRF was found to be governed by the inherent signal variability, in which case the vertical and anterior-posterior components were more reliable and subsequently predicted significantly more accurately than the medio-lateral component. The emerging capability for obtaining continuous GRF records from wearable instrumentation has the potential to permit unprecedented quantification of training stress and competition demands in running.     

Device for on-the-water measurement of rowing output

All those who compete in the sport of rowing have used the land rowing machine, Ergometer (commonly called the ‘erg’), manufactured by Concept II (Morrisville, Vermont, USA). Ergon is the Greek word for work, hence the Ergometer measures work. Rowers are commonly ranked according to their ‘erg score.’ The fault in this ranking is that the land Ergometer cannot account for many of the important technical aspects associated with rowing on the water. The goals of this project were to (1) develop a system for on-the-water measurement of work during rowing and then (2) demonstrate the potential of such a system to quantify performance and improve rowing technique. To achieve these goals, force was measured using strain gauges glued to the shaft of the rowing oar and angular displacement was measured using a potentiometer. The force and displacement measurements were sent to a microcontroller, which calculated the total work done in a particular stroke, as well as other parameters, and displayed the values to the rower. The parameters were used to evaluate the performance of three collegiate rowers on the water. The data were also used to plot force profiles, which were reviewed with each rower and the coach to illustrate the rowers’ habits and facilitate improving technique. One rower was ‘tutored’ with the device through five on-the-water practices, after which his force profiles and parameter values demonstrated significant improvement. The device not only provided a standard to which all rowers were compared on the water, but also supplied the rowers with important information on technical aspects of their strokes and pacing themselves.     

中国群众体育参与的影响因素及驱动力研究简

采用主成分分析与因子分析法,对影响群众体育参与的10个因素进行数据矩阵分析。旨在准确把握中国群众体育参与影响因素和特征。分析确定主成分：驱动因子2个。包括：政府支持和体育发展因子、生活水平与文化素质因子。结果表明,政府支持和体育发展是群众体育参与的基础和保障,生活水平与文化素质影响群众对体育参与的规模与主动性。     

中国乒乓球女子后备力量月经状况的调查与对策研究

对参加中国乒乓球女二队冬训67名运动员的月经状况进行问卷调查。结果表明:早期、长期系统的乒乓球训练对女子运动员月经初潮无明显及不良影响,但是月经初潮年龄有变小的趋势;运动员月经周期异常、痛经和经前期症状发生率较高,但是就诊率较低,月经相关知识欠缺。建议:重视对女子后备力量实施青春生理卫生知识教育、鼓励运动员积极治疗、加强科学训练。     

竞技武术套路运动员表现力的培养方法研究

竞技武术套路比赛中运动员的表现力起着越来越关键的作用。文章运用文献资料法、问卷调查法等研究方法,对影响竞技武术套路运动员表现力的各种因素进行了研究分析。研究结果表明：影响竞技武术套路运动员表现力的因素主要包括气质和性格、赛前心理准备、兴趣、表情和乐感,并针对这些因素对武术套路运动员表现力培养的方法进行了探讨,以指导训练工作。     

肌肉力量连续统一体理论及其在力量训练中的应用研究

通过对肌肉力量中主动张力和被动张力的关系所作的深入探讨,认为肌肉在不同收缩形式和收缩速度下,肌力的组成以及各组成成分之间既相互区别又相互联系,形成一个连续统一体。这为力量训练理论与实践研究开辟了新的思路。     

Sex differences in lower extremity stiffness and kinematics alterations during double-legged drop landings with changes in drop height

The aim of this study was to determine whether sex differences and effect of drop heights exist in stiffness alteration of the lower extremity during a landing task with a drop height increment. Twelve male participants and twelve female participants performed drop landings at two drop heights (DL40 and DL60; in cm). The leg and joint stiffnesses were calculated using a spring–mass model, and the joint angular kinematics were calculated using motion capture. Ground reaction forces (GRFs) were recorded using a force plate. The peak vertical GRF of the females was significantly increased when the drop height was raised from 40 to 60 cm. Significantly less leg and knee stiffness was observed for DL60 in females. The ankle, knee, and hip angular displacement during landing were significantly increased with drop height increment in both sexes. The knee and hip flexion angular velocities at contact were significantly greater for the 60 cm drop height relative to the 40 cm drop height in males. These sex disparities regarding the lower extremity stiffness and kinematics alterations during drop landing with a drop height increment would predispose females to lower extremity injury.     

优秀散打运动员膝/肘关节等速测试与站位攻防技术分析

采用ISOMED2000等速系统检测优秀散打运动员膝、肘关节肌群的生物力学特征,分析优秀散打运动员站位攻防动作技术.在进攻训练中伸膝关节速度达到300°/s,能充分发挥运动员小腿伸肌群的爆发能力;采用300°/s的速度可以快速屈小腿,有利于运动员快速回防,为再次打击对方在时间上创造了条件;在站位时,膝关节角度保持157.3°～160.1°,小腿屈肌群离心爆发能力强,有利于运动员调整自身的身体姿势,避开对方的快速进攻.在进攻训练中应使肘关节速度达到300°/s,能充分发挥运动员前臂伸肌群的爆发能力.肘关节角度在81°～86°的范围,有利于运动员快速出拳,打击对方.以240°/s的速度屈肘,能充分发挥运动员前臂屈肌群的爆发能力,有利于运动员快速回防.在防守训练中,肘关节角度在78°～85°的范围内,对运动员快速回防,抵御时方快速、重拳的进攻是有利的;肘关节角度在128°～137°的范围内,可远距离隔挡对方,阻击对方的快速进攻.