女子举重运动员不同纵跳方式中生物力学参数与专项成绩的相关研究

采用5种不同的纵跳方式，对12名女子举重运动员髋、膝关节的角度、角速度等生物力学参数进行采集，所获数据和举重专项成绩进行相关分析。结果表明：不同纵跳方式中的纵跳高度和专项成绩都有不同程度的相关。其中60cm下落跳中的生物力学参数和专项成绩相关因素最多，尤其是下落后的纵跳高度和弹性能利用率和专项成绩高度相关，相关程度在0．8左右水平。根据以上相关分析结果提出一种针对举重运动员的肌肉快速力量和离心肌力的训练方法，即适宜高度为60cm的跳深练习。     

跳深纵跳练习对跳高运动员起跳腿“承受能力”的测定与分析

采用运动学和动力学相结合的生物力学研究方法对跳高运动员下肢肌的承受能力进行研究,得出如下主要结论:①跳深纵跳练习可以作为提高跳高运动员起跳能力的专项练习;②跳高运动员起跳腿的承受能力直接影响缓冲和蹬伸过程,并最终影响起跳效果;③膝关节和踝关节,尤其是踝关节是二级跳高运动员下肢承受能力的薄弱环节。同时膝关节是最大缓冲时刻的“关键性环节”;④二级跳高运动员产生最大反跳高度的适宜高度为(35.0±4.56)cm,最大反跳高度为(48.00±3.78)cm;⑤适宜高度跳深的冲击载荷与摸高成绩、适宜高度跳深纵跳的反跳高度与助跑摸高成绩均呈高度相关,两者均是评价运动员起跳能力的重要指标。     

不同专项运动员骨骼肌弹性能利用率的比较

对24名专业队田径运动员、30名业余体校田径运动员、12名专业队举重运动员和30名中学生进行了反向跳和不同高度的下落跳测试，比较弹性能利用率。结果表明，弹性能利用率存在性别差异，男性受试者弹性能利用率高于女性；弹性能利用率存在专项差异，男子跳高运动员的弹性能利用率高于男子中长跑运动员，女子举重运动员的弹性能利用率高于女子跳跃和短跑运动员。女子跳远、女子跳高运动员的弹性能利用率与身体素质水平和专项成绩呈显著性的相关。     

关于提高少年举重运动员专项成绩水平的探讨

近年来,在少年举重比赛中,不少举重运动员专项力量水平较高,而专项成绩却不理想。通过调查研究发现,对专项成绩技术动作训练重视程度不够是导致专项成绩不高的主要原因。通过对比观察法,对两组不同级别少年举重运动员进行举重训练,发现重视少年举重运动员技术动作训练是可以提高专项成绩水平的。     

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.     

跳高运动员起跳腿“超等长”收缩能力的生物力学研究

采用运动学和动力学同步实验等研究方法,对30名男子跳高运动员的"超等长"收缩能力进行生物力学研究,针对影响跳高运动员起跳效果的退让性工作能力、蹬伸能力进行不同级别运动员的对比分析,为跳高运动员的专项力量训练提供理论依据.     

跳高运动员专项身体素质与专项成绩相关关系的研究

对 8名男子跳高运动员进行了专项成绩和身体素质测验 ,同时测试了运动员下肢髋、膝、踝 3个关节的等速屈伸肌力。通过相关分析探讨了跳高运动员专项身体素质、下肢力量水平与专项成绩之间的关系。结果表明 ,髋关节屈伸肌力矩、膝关节伸肌力矩、踝关节跖屈肌力矩与跳高专项成绩相关。     

足弓刚度对纵跳动作的下肢生物力学影响

目的：通过对比跳高运动员足弓刚度对单腿纵跳成绩的影响,为跳高运动员选材及专项训练提供理论依据。方法：招募15名男性国家二级跳高运动员,对受试者足部形态进行红外光学扫描,采用红外运动捕捉系统和测力台同步采集受试者纵跳动作的下肢运动学和动力学数据。结果：在纵跳表现中,足弓刚度与地面反作用力峰值间存在线性关系,高刚度足弓受试者的峰值vGRF显著大于低刚度足弓的受试者(P<0.05),高刚度足弓组冲击加载率为15.2BW/s±1.8BW/s,低刚度足弓组地面反作用力加载率为12.3BW/s±0.9BW/s,且存在显著差异(P<0.05)。同时,高刚度足弓组的峰值vGRF时刻踝屈角度(21.24°±4.4°)显著性高于低刚度足弓组的峰值vGRF时刻踝屈角度(24.43°±3.6°),P<0.05。结论：在优秀跳高运动员中,足弓刚度与纵跳过程中的踝膝关节屈伸角度、地面反作用力及加载率有显著影响,且与地面反作用力峰值间存在显著正向线性关系。因此,在跳跃类项目我们应该关注运动员足底肌肉力量训练。在描述跳跃过程中的足部及其生物力学特征时,使用静态足部分类值得纳入考量。     

9～18岁儿童少年纵跳技能的运动学研究

以苏州市区333名在校普通中、小学生为研究对象,使用JVC9800高速摄像机以100fps的速度及德国SIMI-motion录像解析系统对研究对象纵跳技能运动学参数的年龄特征进行研究.结果显示:1)男生纵跳高度呈现逐渐增大的年龄特征,增长的较快时期在13～14岁、17～18岁年龄段;女生在11～12岁年龄段纵跳高度增长最快,13岁以后逐渐下降.2)儿童少年足长与纵跳高度呈低度相关,而足高、跟腱长、小腿长、下肢长等指标与纵跳高度相关不密切.3)纵跳各阶段所用时间(腾空时间除外)的长短与纵跳高度相关不密切.4)儿童少年纵跳时下肢关节角呈现逐渐增大的年龄特征;儿童少年纵跳时适当深蹲起跳效果较好.     

世界优秀男子三级跳远运动员三跳远度与成绩灰色关联分析——兼探讨我国运动员与世界优秀运动员之间的差距

目的：通过对中外优秀男子三级跳远运动员的跳远技术与成绩进行分析,以期能为我国的教练员和运动员提供参考。方法：运用文献资料和灰色关联分析法,对世界优秀男子三级跳远运动员的三跳各跳远度与专项成绩进行综合分析。得出世界优秀男子三级跳远运动员的三跳各跳远度与专项成绩的关联度,并进行排序,分析各跳对专项成绩的影响程度。研究结果表明：第3跳远度是影响三级跳远成绩的最重要的因素,其次是第1跳,最后是第2跳;发现我国运动员在三跳比例、速度利用率多方面都与国外运动员有着一定的差距。建议：我国运动员在三跳中应充分利用水平速度,并获得较好的垂直速度,将速度利用率能力作为突破口,调整好三跳比例。     

The effect of knee angle on the external validity of isometric measures of lower body neuromuscular function

The aim of this study was to evaluate the effect of varying knee angle (120 degrees and 90 degrees) on the external validity of an isometric leg press test with reference to vertical jump performance. Isometric peak force (PF120 and PF90), rate of force development (RFD120 and RFD90), and maximum height reached with a squat jump and counter-movement jump were measured in 14 males. Although RFD120 was significantly correlated with squat jump and counter-movement jump performance (r = 0.71 and 0.69), and the correlations with PF120 approached statistical significance (r = 0.53 and 0.50), neither PF90 nor RFD90 was significantly related to vertical jump performance. Furthermore, although both RFD120 and PF120 were significantly different between the best five and the worst five jumpers, RFD90 and PF90 did not differentiate between individuals' vertical jump performance. We conclude that the choice of joint angle affects the external validity of isometric strength testing. Based on our results, we recommend accurate control of biomechanical specificity and assessment at different angles to find the position at which isometric strength testing is most comfortable.     

The effect of knee angle on the external validity of isometric measures of lower body neuromuscular function

The aim of this study was to evaluate the effect of varying knee angle (120° and 90°) on the external validity of an isometric leg press test with reference to vertical jump performance. Isometric peak force (PF 120 and PF 90 ), rate of force development (RFD 120 and RFD 90 ), and maximum height reached with a squat jump and counter-movement jump were measured in 14 males. Although RFD 120 was significantly correlated with squat jump and counter-movement jump performance ( r = 0.71 and 0.69), and the correlations with PF 120 approached statistical significance ( r = 0.53 and 0.50), neither PF 90 nor RFD 90 was significantly related to vertical jump performance. Furthermore, although both RFD 120 and PF 120 were significantly different between the best five and the worst five jumpers, RFD 90 and PF 90 did not differentiate between individuals' vertical jump performance. We conclude that the choice of joint angle affects the external validity of isometric strength testing. Based on our results, we recommend accurate control of biomechanical specificity and assessment at different angles to find the position at which isometric strength testing is most comfortable.     

肌肉离心收缩的后激活增强效应对纵跳能力的影响

目的：探讨不同离心负荷激活干预对后激活增强效应所产生的影响及有效作用时间。方法：通过对14名普通男性大学生运用肌肉离心收缩激活方式，观察后续纵跳表现的影响。结果：在激活干预后即刻，对照组与离心负荷（105%1RM和125%1RM）激活干预两个实验组纵跳峰值功率和纵跳的高度没有显著差异，激活干预两个组之间的纵跳表现没有显著差异。激活干预的两组在T3和T6时段的纵跳功率峰值均明显高于对照组。在T3时段两个激活干预实验组纵跳高度峰值明显高于对照组，在T6时段，105%1RM激活干预组的纵跳高度明显增加。结论：纵跳测试前加入大强度的离心负荷刺激会小幅度提高纵跳的能力，不同强度离心负荷的激活干预的后激活增强效应差异性不大，采用105%1RM强度的离心负荷激活干预在 3~6 min有明显的后激活增强效应。     

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.     

The influence of squat depth on maximal vertical jump performance

An increase in the period over which a muscle generates force can lead to the generation of greater force and, therefore, for example in jumping, to greater jump height. The aim of this study was to examine the effect of squat depth on maximum vertical jump performance. We hypothesized that jump height would increase with increasing depth of squat due to the greater time available for the generation of muscular force. Ten participants performed jumps from preferred and deep squat positions. A computer model simulated jumps from the different starting postures. The participants showed no difference in jump height in jumps from deep and preferred positions. Simulated jumps produced similar kinematics to the participants' jumps. The optimal squat depth for the simulated jumps was the lowest position the model was able to jump from. Because jumping from a deep squat is rarely practised, it is unlikely that these jumps were optimally coordinated by the participants. Differences in experimental vertical ground reaction force patterns also suggest that jumps from a deep squat are not optimally coordinated. These results suggest there is the potential for athletes to increase jump performance by exploiting a greater range of motion.     

Quantifying the effects of load carriage and fatigue under load on sacral kinematics during countermovement vertical jump with IMU-based method

We present a method for quantifying sacral kinematics during countermovement jumping (CMJ) using an inertial measurement unit (IMU). The IMU-derived sacral kinematic trajectories reproduced motion capture acceleration, velocity, and displacement to within mean (standard deviation) differences of 0.024 (0.088) m/s², 0.023 (0.026) m/s, and 0.003 (0.032) m, respectively, across 252 jumps performed by 14 subjects. The method also quantified differences in maximum sacral displacement to within 1 % and differences in maximum propulsive velocity to within 0.7 % of motion capture estimates. This builds upon existing IMU-based methods for quantifying jump performance, which do not provide sacral kinematic trajectories. The utility of this method is demonstrated by its ability to discriminate jump performance metrics across a diverse subject population. In particular, we found that 21 participants adopted multiple strategies to maximize jump height in unloaded and loaded fresh conditions, but converged to a common strategy when jumping fatigued and under load. Changes in kinematic parameters were evident across conditions, and several changes were significantly associated with changes in jump performance (i.e., height). These parameters include changes in the depth of the countermovement, duration of the propulsive phase and maximum propulsive velocity. Collectively, these results point toward the future use of this method in naturalistic environments and for multiple objectives including biomechanical performance assessment and tracking, fatigue assessment, and jump training.     

跳深练习中弹性能量利用的实验研究

运用Vicon运动影像捕捉分析系统,对运动训练专业二级运动员原地纵跳、半蹲跳及不同高度下落跳深动作进行采集与三维重构,运用V3D系统完成身体质心位置坐标计算。依据肌肉收缩理论,借鉴前人对肌肉弹性能利用的计算方法,对受试者不同高度下落跳深的弹性能利用率进行测试分析。结果表明:一般水平的运动员跳深练习中肌肉弹性能利用率,随着下落高度的增加,表现出"增大—峰值—下降"的单峰波特征,最大利用率大约出现在40 cm的下落高度;原地纵跳练习的肌肉弹性能利用率与跳深练习的最大利用率相接近;仅就肌肉弹性能的利用方面,原地纵跳是一种较好的训练方法。     

The influence of squat depth on maximal vertical jump performance

Abstract

An increase in the period over which a muscle generates force can lead to the generation of greater force and, therefore, for example in jumping, to greater jump height. The aim of this study was to examine the effect of squat depth on maximum vertical jump performance. We hypothesized that jump height would increase with increasing depth of squat due to the greater time available for the generation of muscular force. Ten participants performed jumps from preferred and deep squat positions. A computer model simulated jumps from the different starting postures. The participants showed no difference in jump height in jumps from deep and preferred positions. Simulated jumps produced similar kinematics to the participants' jumps. The optimal squat depth for the simulated jumps was the lowest position the model was able to jump from. Because jumping from a deep squat is rarely practised, it is unlikely that these jumps were optimally coordinated by the participants. Differences in experimental vertical ground reaction force patterns also suggest that jumps from a deep squat are not optimally coordinated. These results suggest there is the potential for athletes to increase jump performance by exploiting a greater range of motion.     

短距离助跑跳远的生物力学分析

为了探讨短距离助跑跳远这一练习方法的运动生物力学意义，本文对跳远运动员的短距离助跑和全程助跑跳远进行高速摄影和三维测力的同步测试．并通过对其分析和研究，结果表明：１）短距离助跑与全程助跑的水平速度、跳跃距离之差约为１０％；２）起跳时间和力作用于垂直方向的时间比全程助跑长；３）腾起角度大于全程助跑；４）身体重心腾起高度和滞空时间与全程助跑相同。