新时期散打技术发展现状分析

采用文献资料法、问卷调查法、专家访谈法、数理统计法、逻辑分析法等针对散打运动的技术现状进行了统计分析.发现现代散打运动中普遍存在:防守反击多,主动进攻少;中小级别运动员以腿法和组合技术动作为主,大级别运动员以拳法和摔法技术动作为主;"贯拳"和"鞭腿"在所有的技术动作中使用频率最高;运动员在比赛中使用步法单一;高分技术动作、新技术动作使用少;比赛中缠抱过多,运动员普遍体能不足.     

“腿”的名称变化

＂腿＂是人与动物躯体的重要组成部分,关于腿的概念,在人类早期就形成了,但在上古汉语中,＂腿＂这个概念,并不叫做腿,而是主要由＂足＂、＂股＂、＂胫＂、＂脚＂这些词来表示的。＂腿＂这个词产生于晋至唐代。＂‘腿’的最初意义既可指大腿,又可指小腿。在＂腿＂字产生之后,＂脚＂字仍可表示＂小腿＂的概念,这种状况延续了很久,一直到现代汉语普通话,＂腿＂字才彻底取代＂脚＂字,成为表示＂腿＂这个概念的唯一单音节专用词。     

Comparison of two methodological approaches for the mechanical analysis of single-joint isoinertial movement using a customised isokinetic dynamometer*

Compared to isokinetic and isometric tests, isoinertial movements have been poorly used to assess single-joint performance. Two calculation procedures were developed to estimate mechanical performance during single-joint isoinertial movements performed on a customised isokinetic dynamometer. The results were also compared to appreciate the effects of measurement systems and calculation procedures. Five participants performed maximal knee extensions at four levels of resistance (30, 50, 70 and 90% of the one-repetition maximum, 1-RM). Joint angular velocity and torque were assessed from customised isokinetic dynamometer measures (method A) and from weight stack kinematic (method B). Bland–Altman plots and mean percent differences (M_diff) were used to assess the level of agreement for mean and peak angular velocity and torque. A Passing–Bablok regression was performed to compare the angular velocity-angle and torque-angle relationships computed from the two analysis methods. The results showed a high level of agreement for all mechanical parameters (M_diff < 6% for all parameters). No statistically significant differences were observed between methods A and B in terms of angular velocity-angle and torque-angle relationships except at 30% of 1-RM for the torque-angle relationship. Both methodologies provide comparable values of angular velocity and torque, offering alternative approaches to assess neuromuscular function from single-joint isoinertial movements.     

优秀跳远运动员起跳环节支撑腿表面肌电活动特征研究

通过表面肌电和运动学同步测试,揭示优秀跳远运动员起跳环节下肢肌肉表面肌电活动特征。研究结果表明：运动员起跳过程中比目鱼肌、腓肠肌、股外侧肌、股内侧肌是起跳腿的主要发力肌肉;所测肌肉最大发力时的顺序为：胫骨前肌首先发力,股外侧肌和股内侧肌次之,腓肠肌、比目鱼肌、股二头肌依次最后发力至最大;在整个起跳环节,踝关节和膝关节的拮抗肌共激活水平较高,其中尤以缓冲阶段踝关节的共激活水平最高。上述特征提示,在专项训练实践中,教练员应设计与跳远起跳用力特征相一致的专项力量训练手段,以打造出良好的专项力量素质。     

纠正轮滑直道前滑向后蹬地错误动作的方法初探

运用文献资料法、对照实验法、数理统计法、归纳分析等研究方法,对在教授初学者时采用的摆动腿直接向支撑腿拉回的收腿技术上附加＂靠脚＂动作条件限制的作用进行分析。结果表明附加＂靠脚＂动作条件限制的实验组向后蹬地动作发生率明显低于对照组。     

Validity and reliability of kick count and rate in freestyle using inertial sensor technology

Abstract

In freestyle swimming the arm action is routinely quantified by stroke count and rate, yet no method is currently available for quantifying kick. In this study, we assessed the validity and reliability of inertial sensor technology (gyroscope) to assess kick count and rate. Twelve Paralympic swimmers completed a 100-m freestyle-swimming time-trial and freestyle kicking-only time-trial three times each in a season. An algorithm was developed to detect the up and down beat of individual kicks from the gyroscope trace. For comparative purposes, underwater video analysis provided the criterion measure. The standard error of the estimate (validity) for kick count, expressed as a coefficient of variation, was 5.9% (90% confidence interval 5.5 to 6.4) for swimming, and 0.6% (0.5 to 0.6) for kicking-only trials. The mean bias for kick count was ?1.7% (?2.4 to ?1.1) for swimming, and ?0.1% (?0.2 to ?0.1) for kicking-only trials. Correlations between the sensor and video for kick count were 0.96 (0.95 to 0.97) for swimming, and 1.00 (1.00 to 1.00) for kicking-only trials. The typical error of the measurement (reliability) between trials was approximately 4% for kick count and rate. The inertial sensors and associated software used generated sufficient validity and reliability estimates to quantify moderate to large changes in kick count and rate in freestyle swimming.     

Markers of isometric training intensity and reductions in resting blood pressure

Abstract

In this study, we examined the correlations between selected markers of isometric training intensity and subsequent reductions in resting blood pressure. Thirteen participants performed a discontinuous incremental isometric exercise test to volitional exhaustion at which point mean torque for the final 2-min stage (2min-torque_peak) and peak heart rate peak (HR_peak) were identified. Also, during 4 weeks of training (3 sessions per week, comprising 4 × 2 min bilateral leg isometric exercise at 95% HR_peak), heart rate (HR_train), torque (Torque_train), and changes in EMG amplitude (ΔEMG_amp) and frequency (ΔEMG_freq) were determined. The markers of training intensity were: Torque_train relative to the 2min-torque_peak (%2min-torque_peak), EMG relative to EMG_peak (%EMG_peak), HR_train ΔEMG_amp, ΔEMG_freq, and %MVC. Mean systolic (?4.9 mmHg) and arterial blood pressure (?2.7mmHg) reductions correlated with %2min-torque_peak (r = ?0.65, P = 0.02 and r = ?0.59, P = 0.03), ΔEMG_amp (r = 0.66, P = 0.01 and r = 0.59, P = 0.03), ΔEMG_freq (r = ?0.67, P = 0.01 and r = ?0.64, P = 0.02), and %EMG_peak (systolic blood pressure only; r = ?0.63, P = 0.02). These markers best reflect the association between isometric training intensity and reduction in resting blood pressure observed after bilateral leg isometric exercise training.     

以运动学为视角分析核心力量训练对男子跳高运动员助跑最后一步和起跳阶段摆动腿的积极影响

本文以广州体育学院田径队5名男子运动员为研究对象,进行20周的核心力量训练,通过三维摄影对实验前后跳高运动员在助跑最后一步和起跳阶段摆动腿的支撑与摆动技术的运动学特征进行分析发现：起跳腿着地时摆动腿摆动的角速度、起跳蹬伸阶段摆动腿最大角速度及身体重心水平速度增加值等差异显著。     

浅析如何提高我国短跑运动员途中跑的能力

途中跑技术在田径短距离跑项目中是最重要的一个技术环节,对短跑成绩起决定作用. 目前,我国短跑运动停滞不前,关键一环是运动员途中跑的能力没有得到有效的提高.通过和世界优秀运动员的比较,从运动技术、运动能力、能量供应等不同角度,分析影响我国短跑运动员途中跑能力的问题所在,提出解决的有效途径,供大家在以后的教学训练中参考.     

对背越式跳高摆动腿技术的探析

运用文献资料法、比较法、数理统计法和逻辑推理法对背越式跳高的起跳过程进行分析,阐释了起跳过程中摆动腿的摆动是否做到位,将影响到跳高的效果,揭示了在起跳过程中摆动腿的摆动动作对跳高成绩具有重要的影响。