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张疆之 《体育科技文献通报》2006,14(3):56-56
本文旨在运用科学的方法对“双屈式”上挺技术进行运动生1.传统“单屈式”预蹲上挺技术由于只强调预蹲时的屈膝动物力学方面的研究,力争进一步挖掘我国举重运动员的潜力,突作,要求预蹲时上体保持正直,因而无法在上挺时最大限度地发破举重上挺技术的瓶颈,为提高我国举重运动整体 相似文献
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浅析挺举上挺技术动作的重要性 总被引：3，自引：0，他引：3
通过采用文献资料法、观察调查法对国内外优秀举重运动员的挺举上挺技术进行研究，研究结果表明：上挺的关键所在是预蹲动作，在预蹲过程中应保持身体重心与杠铃重心垂直向下运动，而且要迅速地由预蹲中的制动转为上挺发力。制动是预蹲与发力的中间环节，起着承上启下的衔接作用。制动时应做到尽快地由预蹲的退让性工作转化为发力阶段的克制性工作，这是上挺成功的关键所在。 相似文献
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浅析挺举上挺技术中的预蹲动作 总被引：3，自引：0，他引：3
１ 前言本人通过多年的训练实践和观察,发现我国挺举上挺技术中的预蹲动作存在缺陷,主要表现在基础教学或训练中人们大都认为,上挺预蹲正确姿势是上体严格保持正直、屈膝下蹲、臀部沿足跟方向垂直下降。但我认为正确预蹲动作应为上挺预蹲,在屈膝的同时相应屈髋,臀部在向下移动时稍向后移动,上体稍出现相应的倾度,这一观点已在国内外运动实践和许多研究资料中得到证实。本文从生物力学的角度分析预蹲动作,初步探讨该预蹲动作的理论根据,旨在改进上挺预蹲动作,使挺举技术得到改善和提高。２ 研究方法运用人体重心稳定平衡原理、运… 相似文献
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举重上挺动作是由预备姿势、预蹲、上挺发力、支撑与起立四部分组成。上挺是将置于锁骨上的杠铃通过预蹲和借助于上挺发力,使杠铃举过头顶至两臂伸直支撑的动作。 相似文献
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从运动学和动力学特征两方面对女子举重箭步挺进行研究,为教练员和运动员认识和寻找适合自己的上挺方式提供理论依据。采用三维录像和三维测力台同步测试的方法进行研究,发现箭步挺下蹲撑铃点高,人体重心下蹲撑铃不太迅速,杠铃上升距离长,所需杠铃上升速度大。但是箭步挺撑铃的前后稳定角及平衡角大,稳定性高,稍有不慎也不会导致动作失败。箭步挺撑铃和起立时间较短,起立距离也较短,消耗的能量少。 相似文献
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论举重上挺动作技术中的关键动作——预蹲制动 总被引：1，自引：0，他引：1
孟宪娟 《哈尔滨体育学院学报》2008,26(3):107-109
通过对组成举重上挺动作的诸多组成部分相互关系的理论分析,和已有的科研资料及常见的实践资料分析,揭示了预蹲制动动作是对上挺发力、下蹲支撑、起立定铃等整个上挺技术起决定性、规定性影响的关键动作,强调了预蹲制动技术的教学和训练在上挺技术中的重要作用,目的是帮助广大教练员清楚认识上挺动作技术的重要环节,为改变目前我国挺举水平仍然相对落后的局面做出一些应有的贡献。 相似文献
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目的:为国家举重队备战东京奥运会提供科技支撑及举重的运动训练乃至运动员选材提供科学依据。方法:采用德国SIMI-Motion7.50三维运动解析系统对廖秋云打破世界纪录的挺举技术动作视频进行解析,解析的采样频率为50 Hz,运用截断频率为6Hz低通滤波对原始数据进行平滑处理,使用DLT计算空间坐标。结果:①廖秋云提铃至胸阶段的技术堪称完美,准备姿势合理,引膝动作完成质量高。采用积极的伸髋发力,且躯干角度保持80.27deg至77.62deg之间,有利于腹背肌群参与发力。屈髋屈膝接铃,杠铃回落距离为身高的19.61%,属于合理的杠铃回落距离。②上挺阶段,过渡阶段和预蹲制动阶段用时过长。准备姿势站距的调整将降低杠铃所需送达的最终高度,且有利于上挺动作的稳定性。其箭步式上挺杠铃回落距离仅为9.80cm,回落距离小,且双足构成的稳定区域面积大。发力时两心距离控制在3.1cm内,属于理想距离。站稳起立时段末,杠铃向右偏移达17.70cm,对其支撑可能存在隐患。③总体上看,廖秋云的技术优势在于躯干角度控制得当,两心距离始终较近。下肢关节角度变化趋势合理,伸髋发力的方式正确。④廖秋云技术优势明显,但成绩仍具有上升空间。建议优化时间结构,缩短过渡时间,避免额外的能量消耗。缩短预蹲制动时间,提升下肢离心收缩转向心收缩的能力。站稳时段的杠铃横向偏移过大,提示进行左右侧肌肉体量测试评价,并加强弱侧肌肉力量训练。 相似文献
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通过膝关节载荷静力学分析,进一步认识了杠铃力量训练过程中膝关节的力学特点和变化规律。并基于膝关节载荷静力学分析,探讨了杠铃力量训练在力量练习结构、练习方式和练习动作方面的专项化问题。认为杠铃力量训练可以帮助运动员建立专项最需要的力量结构;可以通过不同的练习方式使那些对专项技术最具影响的肌肉或肌群得到训练;力量训练需要紧密结合专项特点,才能获得更好的效果。 相似文献
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举重运动员抓举动作脊柱腰椎节段受力特点分析
———基于有限元理论 总被引：1，自引：1，他引：0
利用CT扫描数据建立具有高度几何材料相似性的腰椎运动节段(L1-L2)的三维有限元模型,分析举重运动员抓举完全起立阶段脊柱腰椎节段生物力学特性,以便对举重运动员腰部损伤进行积极的预防,减少伤病的发生.结果表明:在举重运动员抓举完全起立姿态下,其椎体主要的应力分布在小关节和椎弓根处,椎间盘接触压力主要集中在纤维环中后部,位移主要集中在椎间盘的后外侧;此时,如果杠铃的重量过大,运动员腰部力量不足,引起腰椎关节失稳,会造成椎间盘过分挤压,且在重力的作用下峡部向前剪切力过大可引起峡部裂伤.本研究所建立的腰椎L1-L2节段的三维有限元模型足重要的脊柱生物力学研究平台,可应用于众多相关研究领域. 相似文献
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Chiu LZ Schilling BK Fry AC Salem GJ 《Sports biomechanics / International Society of Biomechanics in Sports》2008,7(2):260-273
For simplicity of biomechanical analyses, the weightlifting barbell is typically modelled as a rigid, nondeformable object. Most coaches and weightlifters, however, are aware of the elastic nature of the barbell, and its influence on the successful completion of lifting attempts. Variables such as velocity, work performed, and power output are indicators of the quality of performance during the snatch, clean, and related weightlifting pulling movements. The aim of this study was to establish whether differences exist in determining these biomechanical parameters when the centre of the barbell is analysed compared with each end of the barbell. Nine men performed three maximal-effort repetitions in the clean pull exercise at 85% of their self-reported single repetition maximum (1-RM) clean (90-155 kg) using a barbell instrumented for mechanical analysis. Results indicated that peak barbell speed was 5-30% (P < 0.05) lower for the centre of the barbell than the ends. Although differences (P < 0.05) in kinetic and potential energy were found between the centre and ends of the bar, differences between total work performed were small (< 6%; P < 0.05) and no differences were observed for average power (P > 0.05). Although approximately the same work and power occur for the centre and ends of the barbell, they manifest as different kinematics as a result of the elastic nature of the equipment. The elastic characteristics should be considered when selecting instrumentation and variables for research involving barbells. Coaches should be aware of the elasticity of barbells, including selecting appropriate viewing angles as well as understanding how deformation may affect the ends of the barbell relative to the centre. 相似文献
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We investigated the linear kinematics and the change in energy of the barbell and the angular kinematics of the trunk and leg during the snatch technique of 12 elite male Greek weightlifters under competitive conditions after the new weight classification. Two S-VHS cameras operating at 60 Hz were used to record the lifts. The spatial coordinates of selected points were calculated using the direct linear transformation procedure; after digital filtering of the raw data, the angular displacements and angular velocities were calculated for the hip, knee and ankle joints. The following variables were also calculated for the barbell: vertical and horizontal displacement, vertical linear velocity and acceleration, external mechanical work and power output. The results revealed that all weightlifters flexed their knees during the transition phase, independently of their weight category. This indicates that the athletes use the elastic energy produced during the stretch-shortening cycle to enhance their performance. In nine athletes, we found that the barbell trajectory did not cross a vertical reference line that passed through the initial position of the barbell. The vertical linear velocity of the barbell was increased continuously from the beginning of the movement until the second maximum extension of the knee joint, with no notable dip being observed. Regarding the change in energy of the barbell, we found that the mechanical work for the vertical displacement of the barbell in the first pull was significantly greater than the mechanical work in the second pull. In contrast, the estimated average mechanical power output of the athletes during the vertical displacement of the barbell was significantly greater in the second pull than in the first pull. We conclude that the major elements of the snatch technique of elite Greek weightlifters have not been affected by the new weight classification. 相似文献
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Loren Z. F. Chiu Brian K. Schilling Andrew C. Fry George J. Salem 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):260-273
For simplicity of biomechanical analyses, the weightlifting barbell is typically modelled as a rigid, non-deformable object. Most coaches and weightlifters, however, are aware of the elastic nature of the barbell, and its influence on the successful completion of lifting attempts. Variables such as velocity, work performed, and power output are indicators of the quality of performance during the snatch, clean, and related weightlifting pulling movements. The aim of this study was to establish whether differences exist in determining these biomechanical parameters when the centre of the barbell is analysed compared with each end of the barbell. Nine men performed three maximal-effort repetitions in the clean pull exercise at 85% of their self-reported single repetition maximum (1-RM) clean (90–155 kg) using a barbell instrumented for mechanical analysis. Results indicated that peak barbell speed was 5–30% (P < 0.05) lower for the centre of the barbell than the ends. Although differences (P < 0.05) in kinetic and potential energy were found between the centre and ends of the bar, differences between total work performed were small ( < 6%; P < 0.05) and no differences were observed for average power (P > 0.05). Although approximately the same work and power occur for the centre and ends of the barbell, they manifest as different kinematics as a result of the elastic nature of the equipment. The elastic characteristics should be considered when selecting instrumentation and variables for research involving barbells. Coaches should be aware of the elasticity of barbells, including selecting appropriate viewing angles as well as understanding how deformation may affect the ends of the barbell relative to the centre. 相似文献
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Vassilios Gourgoulis Nickos Aggelousis Giorgos Mavromatis Athanasios Garas 《Journal of sports sciences》2013,31(8):643-652
We investigated the linear kinematics and the change in energy of the barbell and the angular kinematics of the trunk and leg during the snatch technique of 12 elite male Greek weightlifters under competitive conditions after the new weight classification. Two S-VHS cameras operating at 60 Hz were used to record the lifts. The spatial coordinates of selected points were calculated using the direct linear transformation procedure; after digital filtering of the raw data, the angular displacements and angular velocities were calculated for the hip, knee and ankle joints. The following variables were also calculated for the barbell: vertical and horizontal displacement, vertical linear velocity and acceleration, external mechanical work and power output. The results revealed that all weightlifters flexed their knees during the transition phase, independently of their weight category. This indicates that the athletes use the elastic energy produced during the stretch–shortening cycle to enhance their performance. In nine athletes, we found that the barbell trajectory did not cross a vertical reference line that passed through the initial position of the barbell. The vertical linear velocity of the barbell was increased continuously from the beginning of the movement until the second maximum extension of the knee joint, with no notable dip being observed. Regarding the change in energy of the barbell, we found that the mechanical work for the vertical displacement of the barbell in the first pull was significantly greater than the mechanical work in the second pull. In contrast, the estimated average mechanical power output of the athletes during the vertical displacement of the barbell was significantly greater in the second pull than in the first pull. We conclude that the major elements of the snatch technique of elite Greek weightlifters have not been aff ected by the new weight classification. 相似文献
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Kristof Kipp Carolyn Meinerz 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):272-282
Although the power clean is an almost ubiquitous exercise in the strength and conditioning setting, relatively little is known about the biomechanics of successful and unsuccessful power clean lift attempts. The purpose of this study was to determine biomechanical differences between successful and unsuccessful power clean lift attempts in male collegiate athletes. Fifteen male lacrosse players (Age: 20.1 ± 1.2; Height: 1.78 ± 0.07 m; Body mass: 80.4 ± 8.1 kg; Relative one-repetition maximum power clean: 1.25 ± 0.13 kg/kg) were videotaped during a lifting session that required the completion of maximal effort power cleans to establish a one-repetition maximum. The position of the barbell was digitised and used to calculate the displacement, velocity, acceleration, and acceleration vector of the barbell. The results revealed that unsuccessful attempts were characterised by differences during the second pull phase. Unsuccessful lifts exhibited greater peak forward barbell displacement, lower backward barbell velocities, and lower resultant acceleration angles during the second pull. Strength and conditioning coaches should therefore emphasise limited forward motion of the barbell during the second pull and instruct athletes to generate a more backward-directed force during the second pull in order to lift greater loads during testing and subsequent lifting sessions. 相似文献
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用每周一次的肌肉力量训练频率的方法,对高校从未受过常规定期的肌肉力量训练普通大学生,进行在每周一次的体育课上进行了为期10周的肌肉力量训练实验,以观察肌肉力量训练产生的效果。训练前后为他们测试了卧推杠铃和直立杠铃弯举的成绩（1RM）,还分别测量了练习前后大腿围和上臂围等。训练周期以后1RM比开始前增加了10%以上,不管是卧推杠铃还是直立杠铃弯举等项目都有明显的进步。结果表明,每周一次频率的肌肉力量练习确实能增加大学生的肌肉力量,但这种形式的锻炼并未能使身体形态发生明显的变化。 相似文献
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Kimitake Sato William A. Sands Michael H. Stone 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):524-531
The purposes of the study were to track weightlifters' barbell acceleration with a portable accelerometer over three training sessions to examine test–retest reliability and to compare peak barbell acceleration at different training intensities. Twelve nationally ranked weightlifters volunteered for this study. The portable accelerometer was attached to the right side of the barbell to measure barbell resultant acceleration during the snatch lift at a sampling frequency of 100 Hz. The data were collected over three training sessions at intensity levels of 80%, 85%, and 90% of one repetition maximum. The data were analyzed using intra-class correlation coefficients (ICCs) for the three training sessions and one-way repeated measure ANOVA to compare the difference in peak barbell acceleration at three intensities. Results showed that the device was highly reliable with an ICC of 0.88 and 95% confidence interval of 0.81–0.93. There were significant differences in peak barbell acceleration at various lifting intensities, indicating a decline of the acceleration as the mass of the barbell became heavier. The portable accelerometer seems useful in measuring barbell acceleration data, which can be analyzed in future studies to monitor a weightlifter's performance in a practical setting instead of testing at a laboratory. 相似文献
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Dynamic squat is one of the most executed fitness exercise. Its use is widespread both for rehabilitation and training purposes. Several typologies of the squat exercise can be performed. The most important are the front squat and the back squat. In the front squat the barbell is held in front of the body across the clavicles and deltoids, while in the back squat exercise the bar is held on the back of the body at the base of the neck. In this paper we will refer to dynamic back squat. The squat exercise can be performed with or without the help of a machine that has the scope of guiding the person during the movement and ensuring his stability and safety. The use of this type of machine is often necessary when the workout is heavy and the risk of incorrect exercise and injuries is high. On the other hand, the rigid structure of this device often overconstrains the lifting movement. From all these observations, the purpose of the paper is to discuss an alternative design of a mechanism able to maintain the advantage to allow a free-body execution and to preserve the safety of the athletes as well. The proposed mechanism has been designed starting from an anthropometric study on the squat movement. This has been performed by using a motion capture system and applying computer-aided engineering techniques. The design activity started from the experimental investigation of the trajectory of the barbell during the natural execution of the unrestricted back squat exercise. The tests have been performed on several subjects with different mass, anthropometry and gender. In a second phase, the data have been processed and analyzed and a specific mechanism, able to reproduce the natural trajectories, has been synthetized. Finally, the design and optimization of the entire structure has been performed through the use of virtual prototyping techniques. 相似文献