原地摆臂纵跳和抱头纵跳动力学特征的比较

运用三维测力台(Kistler)和红外光点自动捕捉测试系统(Qualisys-MCU500)对北京体育大学男子排球队9名运动员分别进行了摆臂纵跳和抱头纵跳的测试,结果表明:摆臂纵跳蹬伸过程中最大力值大于抱头纵跳,但是由于蹬伸后半段时间的延长使后半段蹬伸力的梯度值没有明显增加;落地时地面最大冲击力与纵跳高度无关;摆臂纵跳的冲量值大于抱头纵跳,但研究结果发现纵跳高度与冲量并没有显著性相关关系.     

三级蛙跳练习六法

<正>三级蛙跳的完整技术过程是:两脚自然平行开立站在起跳线后,脚尖不得踩线,原地两脚同时起跳,连续跳三级。它的技术要求是:起跳前可预先摆臂,当双臂向前上方摆起时,双脚蹬地向前跳起,连跳过程中必须双脚同时落地、同时起跳,三跳之间必须连贯协调完成,不能停顿。要做到连贯协调即每一跳只能摆臂一次不得摆臂两次或两次以上。在教学实践中如何让学生快速而有效地掌握三级蛙跳的技术,提高三级蛙跳的成绩呢?     

立定跳远中摆臂错误的原因与对策

在平时立定跳远学习中经常会看到以下三种情况：一是学生在跳之前摆臂,但在要跳的时候手臂却不摆动了;二是学生手臂在向后摆的时候人跳出去了;三是多次或反复摆臂,但在跳出去之前,摆臂动作突然出现节奏的变化。这三种摆臂情况很明显不能对跳远的成绩起到积极作用。第一种情况摆臂没有起到任何作用,做的是无用功;第二种摆臂情况对整个动作结构起到破坏的作用,人在向前跳,手臂在向后摆,不符合运动规律;     

对我国不同水平男子跳远教练员专项力量训练计划及安排特点的比较

运用专家访谈法、问卷调查法和数理统计法等对我国不同水平男子跳远教练员专项力量训练的特点进行了专题研究．结果表明：与二三线跳远教练员相比,在专项力量训练内容上,一线跳远教练员更加注重加速跑时腿部肌群所需的爆发力和上肢摆动力量的训练;在专项力量训练的手段上,一线教练员更多的采用助跑2．4步五级跨步跳、米跳（计时跳）和持哑铃原地摆臂等练习手段。     

基于“学、练、赛”的初中原地纵跳摸高课堂教学实践

<正>一、原地纵跳摸高的学练方法学生在进行原地纵跳摸高的练习中,教师可注重情境诱发,激发学生的学习兴趣。如,通过观看排球扣球、篮球原地跳起投篮、羽毛球扣杀等视频,理解原地纵跳摸高的技术结构,再有针对性地练习技术和体能。1.原地纵跳摸高的技术练习原地摆臂练习：让学生将双手放在背后,先练习无摆臂纵跳,再练习摆臂纵跳,通过这种练习对比,让学生体验摆动双臂能增加纵跳高度,激发学生学习的积极性。     

短跑教学的易错动作及纠正方法

<正>一、容易产生的错误动作及纠正方法 1.跑时步幅迈不开产生原因:注意力过于集中在提高步频方面,腿前摆过低,膝关节紧张。纠正方法:宽大步幅划线跑,男生每步在2.10米左右,女生2米左右;多做行进间垫跳高抬腿跑。2.摆臂方法和方向不正确产生原因:摆臂技术概念不清,重视不够,肩部紧张。纠正方法:示范正确的摆臂方法及强调摆臂在途中跑时的意义;多做原地连续提腿摆臂的辅助练习;做节奏跑、节奏跳     

游泳接力项目两种接跳出发技术对比分析

选择10名广州大学高水平男子游泳运动员为研究对象,采用测力板、高速摄像机等仪器设备同步采集运动学和动力学参数资料,对游泳接力项目中常用的两种接跳出发技术进行对比分析,选择更适宜接力项目的摆臂式出发技术对自由泳成绩最好的4名运动员进行为期4周的接跳训练,籍以探讨两种接跳出发技术的优劣及摆臂式出发技术训练对接跳时间的成效.结果表明,摆臂式出发技术相对于抓台式出发技术具有较大起跳角度、垂直速度和起跳作用力,入水阻力小,在入水距离、出发10m时间具有较大的优势,更适合游泳接力的项目特点,更适宜在游泳接力项目中使用.实验证明,运动员经过较长时间的接跳训练,采用摆臂式出发技术可以明显提高游泳接力项目的接跳时间.     

运动生物力学

C804.6 9901106摆臂在纵跳动作中的生物力学研究=Biomechanicalstudy on the arm motion in vertical jump〔刊,中,I〕/朱国生//中国体育科技.-1998.-34(12).-70-74图1表9(BJ)纵跳//摆臂//生物力学//研究//力学分析本文主要运用三维测力系统,进行不同膝角的摆臂与不摆臂原地纵跳测试与分析,探讨了摆臂在纵跳动作中的作用及其生物力学特征和规律,丰富了已有研究内容。G804.6,G815.166 9901107德国运动生物力学理论与方法学研究概述及思考=Thought and review Of theory and methodologyresearch of sports biomechanics in Germany〔刊,中,I〕/李建设//中国体育科技.-1999.-35(1).-16-19参9(BJ)德国//运动生物力学//理论//方法//综述//科研//测量//研究方法考察、研究德国运动生物力学的学科任务与研究     

青少年男运动员关节输出相对峰力矩与纵跳成绩关联分析

纵跳能力是体育运动中各类跳跃动作的基础,也是衡量身体素质的重要指标之一。本文通过文献资料法和实验法,对体校17-18岁男运动员进行随机抽样30名,然后利用多因素优势分析法,得出各关节与纵跳高度的关系,从而找出纵跳与哪一个关节较为密切,为教学与训练提供理论依据。1、测试结果从站立开始加摆臂纵跳就是我们通常所说的反向蹲跳。通过统计处理得出如下结论:     

立定跳远的专门练习方法

正一、立定跳远的规范动作全身放松,两脚开立与肩同宽,预备摆臂,身体半蹲,两臂上摆,脚尖蹬离地面,腾空展体,收腹,伸腿,落地,两臂积极前伸。二、针对规范动作的各个环节进行的专门性练习方法(一)预备摆臂预备摆臂时,下肢需要做到一伸(两腿伸直)二屈(屈膝)降重心的发力顺序,动作要协调、流畅。至于摆臂的次数,有的人认为两臂摆动一次最好,但在实际练习中,摆臂的次数应该根据各人的习惯而定,建议不超过3次,如果预摆次数多就不要急于屈膝。针对"一伸二屈降重心"采用的练习方法:1.技术动作。原地练习摆臂3次,让学生原地起跳;在草坪上或沙坑里连续纵跳5次。让学生把立定跳远的摆臂动作能连续协调地做好。2.力量方面。两个学生推小车距离20~30米、卧推哑铃或杠铃6次×6组、站在与墙保持1米左右的距离推墙10     

Segmental and kinetic contributions in vertical jumps performed with and without an arm swing

To determine the contributions of the motions of the body segments to the vertical ground reaction force (Fz), the joint torques produced by the leg muscles, and the time course of vertical velocity generation during a vertical jump, 15 men were videotaped performing countermovement vertical jumps from a force plate with and without an arm swing. Linear kinematic, Fz, and joint torque data were computed and compared using repeated measures analysis of variance. Maximum jump height was significantly larger in the arm swing jumps compared to the no arm swing jumps and was due to both a higher height of the center of mass (CM) at takeoff (54%) and a larger vertical velocity of the CM at takeoff (46%). The net vertical impulse created during the propulsive phase of the arm swing jumps was greater due to a trend of an increased duration (0.021 s) of the propulsive phase and not to larger average values of Fz. In the arm swing jumps, the arm motion resulted in the arms making a larger maximal contribution to Fz during the middle of the propulsive phase and decreased the negative contribution of the trunk-head and thigh to Fz late in the propulsive phase. Last, the arm swing decreased the extensor torques at the hip (13%), knee (10%), and ankle (10%) early in the propulsive phase but augmented these same extensor torques later in the propulsive phase.     

Evaluation of Four Vertical Jump Tests: Methodology,Reliability, Validity,and Accuracy

Vertical jump performance tests can give considerably different results, even when different methods are used to analyze the same jump trial from the same subject. To evaluate and compare 4 different methods commonly used to measure vertical jump performance, 52 physically active men each performed 5 maximal vertical jumps. Kinetic and kinematic data were used to analyze each trial using the 4 methods: a criterion test based on body center of mass displacement (VJPT), 2 methods based on vertical takeoff velocity as calculated from the force platform, and 1 method based on time in the air (JUMPAIR). All 4 methods showed excellent reliability (R > .97). Using VJPT as the criterion, the other 3 methods showed excellent coefficients of validity (R > .95) but poor accuracy: The obtained vertical jump height scores were statistically different among all methods (p < .01). JUMPAIR is considered a relatively simple and inexpensive method to obtain valid and reliable measures of vertical jump performance without an arm swing, provided the appropriate adjustments are made to the jump results.     

PART VII: PSYCHOLOGY AND MOTOR CONTROL

The main aim of this study was to examine the age- and sex-associated variation in neuromuscular capacities of young distance runners. A secondary aim was to compare the magnitude of sex differences in young athletes in the same sport compared with the general population. Twenty-seven male and 27 female distance runners were enrolled in the study, whose ages ranged from 8.0 to 15.1 years at initial visit. Twenty males and 16 females were followed at approximate annual intervals for 4 or 5 years. Seven neuromuscular capacities were measured: quadrant jump, figure 8 run, standing long jump, vertical jump, flexed arm hang, sit-and-reach and sit-up. Age- and sex-associated variation was analysed by two-way analysis of variance. There were significant main effects for age for quadrant jump, figure 8 run, long jump, vertical jump, sit-and-reach and sit-up. There were significant main effects for sex for figure 8 run, long jump, vertical jump, flexed arm hang and sit-and-reach. The interaction between age and sex was statistically significant for long jump and vertical jump. In general, differences in neuromuscular agility (figure 8 run, quadrant jump) and explosiveness-power (long jump, vertical jump) between the sexes were attenuated before 13 years of age in young distance runners. However, during the adolescent growth spurt, differences in agility and power between the sexes emerged as a result of a continued increase in males and a plateau in females. Differences between the sexes in upper body neuromuscular endurance (flexed arm hang) and sit-and-reach persisted throughout the age range. The magnitude of sex differences between the runners and the general population varied by age and neuromuscular capacity.     

Age- and sex-associated variation in neuromuscular capacities of adolescent distance runners

The main aim of this study was to examine the age- and sex-associated variation in neuromuscular capacities of young distance runners. A secondary aim was to compare the magnitude of sex differences in young athletes in the same sport compared with the general population. Twenty-seven male and 27 female distance runners were enrolled in the study, whose ages ranged from 8.0 to 15.1 years at initial visit. Twenty males and 16 females were followed at approximate annual intervals for 4 or 5 years. Seven neuromuscular capacities were measured: quadrant jump, figure 8 run, standing long jump, vertical jump, flexed arm hang, sit-and-reach and sit-up. Age- and sex-associated variation was analysed by two-way analysis of variance. There were significant main effects for age for quadrant jump, figure 8 run, long jump, vertical jump, sit-and-reach and sit-up. There were significant main effects for sex for figure 8 run, long jump, vertical jump, flexed arm hang and sit-and-reach. The interaction between age and sex was statistically significant for long jump and vertical jump. In general, differences in neuromuscular agility (figure 8 run, quadrant jump) and explosiveness-power (long jump, vertical jump) between the sexes were attenuated before 13 years of age in young distance runners. However, during the adolescent growth spurt, differences in agility and power between the sexes emerged as a result of a continued increase in males and a plateau in females. Differences between the sexes in upper body neuromuscular endurance (flexed arm hang) and sit-and-reach persisted throughout the age range. The magnitude of sex differences between the runners and the general population varied by age and neuromuscular capacity.     

The energetics and benefit of an arm swing in submaximal and maximal vertical jump performance

Abstract

The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to “pull” on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.     

The energetics and benefit of an arm swing in submaximal and maximal vertical jump performance

The aims of this study were to investigate the energy build-up and dissipation mechanisms associated with using an arm swing in submaximal and maximal vertical jumping and to establish the energy benefit of this arm swing. Twenty adult males were asked to perform a series of submaximal and maximal vertical jumps while using an arm swing. Force, motion and electromyographic data were recorded during each performance and used to compute a range of kinematic and kinetic variables, including ankle, knee, hip, shoulder and elbow joint powers and work done. It was found that the energy benefit of using an arm swing appears to be closely related to the maximum kinetic energy of the arms during their downswing, and increases as jump height increases. As jump height increases, energy in the arms is built up by a greater range of motion at the shoulder and greater effort of the shoulder and elbow muscles but, as jump height approaches maximum, these sources are supplemented by energy supplied by the trunk due to its earlier extension in the movement. The kinetic energy developed by the arms is used to increase their potential energy at take-off but also to store and return energy from the lower limbs and to "pull" on the rest of the body. These latter two mechanisms become more important as jump height increases with the pull being the more important of the two. We conclude that an arm swing contributes to jump performance in submaximal as well as maximal jumping but the energy generation and dissipation sources change as performance approaches maximum.     

An analysis of two styles of arm action in the vertical countermovement jump

The aim of this study was to determine the effect of two arm swing techniques, the simultaneous arm swing and the early arm swing, on vertical countermovement jump performance and on the contribution of the arms to vertical movement at the centre of mass (CM) during the propulsion phase. Participants were 28 athletes practicing sports in which the vertical jump constitutes a basic ability. Ground reaction forces were recorded by a force platform and the sagittal plane motion was recorded by a video camera. Although at take-off the vertical velocity (2.7 ± 0.2 m/s for simultaneous technique vs. 2.8 ± 0.2 m/s for early technique; p = 0.040) and position (1.18 ± 0.06 m for simultaneous vs. 1.17 ± 0.05 m for early; p = 0.033) of the CM were significantly different, no difference was observed in jump height (1.56 ± 0.01 m in both techniques). The arm action differed during the initial and final propulsion phases in both styles but the accumulated vertical contribution was similar. The practical implication in sports is that the use of the arm-swing technique to reach the maximum jump height should be determined by tactical demands instead of the technical execution of the arms.     

我国优秀男子跳远运动员起跳中不同时相速度变化特征

采用现场定点高速摄影、影片解析及数理统计等研究方法。结果表明，我国优秀男子跳远运动员起跳缓冲阶段，身体重心水平速度减小，并与垂直速度增加之间存在密切关系；蹬伸阶段身体重心水平速度略有回升，垂直速度保持增加的态势，且离板瞬间身体重心水平速度和垂直速度都呈现出相对较大的趋势。     

Biomechanical differences of arm swing countermovement jumps on sand and rigid surface performed by elite beach volleyball players

The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p < .05) surface effects on the jump height, the ankle joint angle at the lowest height of the body center of mass and the ankle angular velocity. Also, significant arm swing effects were found on jump height, maximum power output, temporal parameters, range of motion and angular velocity of the hip. These findings could be attributed to the instability of the sand, which resulted in reduced peak power output due to the differences of body configuration at the lowest body position and lower limb joints’ range of motion. The combined effect of the backward arm swing and the recoil of the sand that resulted in decreased resistance at ankle plantar flexion should be controlled at the preparation of selected jumping tasks in beach-volleyball.     

The rating of perceived exertion predicts intermittent vertical jump demand and performance

The aims of this study were (a) to assess the ability of the rating of perceived exertion (RPE) to predict performance (i.e. number of vertical jumps performed to a fixed jump height) of an intermittent vertical jump exercise, and (b) to determine the ability of RPE to describe the physiological demand of such exercise. Eight healthy men performed intermittent vertical jumps with rest periods of 4, 5, and 6 s until fatigue. Heart rate and RPE were recorded every five jumps throughout the sessions. The number of vertical jumps performed was also recorded. Random coefficient growth curve analysis identified relationships between the number of vertical jumps and both RPE and heart rate for which there were similar slopes. In addition, there were no differences between individual slopes and the mean slope for either RPE or heart rate. Moreover, RPE and number of jumps were highly correlated throughout all sessions (r = 0.97-0.99; P < 0.001), as were RPE and heart rate (r = 0.93-0.97; P < 0.001). The findings suggest that RPE can both predict the performance of intermittent vertical jump exercise and describe the physiological demands of such exercise.