举重抓举和下蹲翻运动学比较与用力特征分析

运用三维运动学的研究方法对参加2003年全国女子举重锦标赛的10名运动员的抓举和下蹲翻进行运动学分析并对力量的特点进行比较分析;运用逆向动力学方法对两种技术动作的主要关节的净力矩进行比较分析。结果表明,膝关节角度在提铃离地时刻有显著性的差异;对力量参数回归分析表明,运动员抓举杠铃重量的能力很大程度上取决于运动员所能够输出的最大功率,而运动员下蹲翻杠铃重量的能力很大程度上取决于运动员对杠铃的作用力的积累过程;对于抓举和下蹲翻动作髋关节净力矩分析表明,对于抓举,髋关节最大净力矩与对应此时刻的髋关节角度呈负相关,而对于下蹲翻,髋关节最大净力矩则与所试举的杠铃重量呈正相关。     

在铅球训练中的力量、爆发力和速度

在铅球训练中,杠铃练习是一种十分有效的重要手段。由于铅球的质量是固定的,所以,我们不一定强求在杠铃练习中不断地增加杠铃的重量,可保持杠铃重量不变而要求运动员在练习中加快完成动作的速度。杠铃练习数量的增加并不等于力量的增加。前者的增加可能是运动员通过多次练习     

挺举上挺阶段的功率分析

应用运动生物力学的研究方法对挺举上挺阶段运动员的输出功率进行了分析。分析结果表明:发力阶段运动员单位杠铃重量的平均输出功率和最大瞬时输出功率对上挺时杠铃的最大速度起决定作用。本研究还确定了最大瞬时输出功率,杠铃重量与杠铃最大速度和最大升高参数之间的定量关系,探讨了预蹲制动阶段的力学参数对发力阶段最大瞬时输出功率的影响,并应用功率参数对运动员的运动能力进行了初步的分析。     

保加利亚举重运动员的选材

举重成绩受多种因素的影响。体力方面有:肌力、速度、柔韧性、协调性和耐力;技术方面有:高效率的正确动作,心理方面有:精力集中,勇气和决心;战术方面有:最佳体重制定、体重控制、体重调节等。举重运动发展到今天,单凭力气成不了一流运动员,还必须掌握正确动作,以便把具有的最大肌肉高效率地运用于杠铃上。以最小的体重举起最大重量已成为优秀运动员所必备的条件。     

女子田径运动员力量训练的注意事项

力量训练是田径运动训练的重要内容之一。由于男女在身体形态和机能等诸多方面的先天差异,女子田径运动员在力量训练方法上与男子运动员相比有其异同点。 1．极限重量训练是最有效的方法力量训练方法按负荷的重量可分中重量、大重量、次极限重量、极限重量训练。男女运动员在提高最大力量时,采用的最有效的方法是极限重量训练,也就是通过负荷最大重量进行的力量练习。这种方法能通过对抗超负荷     

举重运动员参加重大比赛的战术方案和对举重运动员战术和意志训练程度进行客观评价的标准

1.在第二、三次试举时给杠铃增重的战术方案在专门的文献里,对第二、三次试举时给杠铃增重的战术问题尚缺乏研究。根据布舒耶夫(1963)的观点,在第二次试举时杠铃的重量应增加5公斤,而在第三次试举时增加2.5公斤,也就是举重比赛规则所允许的杠铃重量的最低增加量。鲍日科(1967)认为,在第二次试举时杠铃的重量应增加7.5或10公斤,而在第三次试举时则应增加2.5或5公斤。我们多年的研究和观察证明,最近几年来,在有世界上最优秀的举重运动员参加的情况下,出现了一种用不太大的重量     

我国优秀男子举重运动员抓举关键技术位移类指标分析

目的：讨论我国优秀男子举重运动员抓举关键技术。方法：以国内重要比赛优秀运动员的抓举技术为研究对象,利用SIMI°Motion 7.50运动动作解析系统对视频数据进行分析处理,采用SPSS22.0统计软件对位移类指标数据进行统计学分析。结果：我国优秀运动员抓举动作中身高与杠铃最大垂直高度呈正相关（r=0.680,P<0.01）,抓举杠铃最大垂直高度相对于运动员身高的相对高度（XHVmax）为73±2%;运动员身高与发力点杠铃垂直高度呈正相关（r=0.680,P<0.01）,发力点杠铃垂直高度/身高的相对高度（XHFL）四个级别间不具有显著性差异,发力点杠铃垂直高度/身高的相对高度（XHFL）为39±2%;我国优秀男子举重运动员铃速最大时杠铃垂直高度（HVmax）为0.90±0.05m,铃速最大时杠铃垂直高度/身高的相对高度为（XHVmax）55±2%,杠铃回落距离（HHL）为0.14±0.03m,杠铃支撑点垂直高度为1.04±0.06m,杠铃支撑点垂直高度相对运动员身高的相对高度为64±3%。结论：抓举位移类指标是评价优秀运动员抓举技术的关键指标,运动员可根据自身特点选择合理...     

浅谈举重比赛中的技战术

由于举重比赛只是运动员与杠铃的接触,运动员之间不存在着直接对抗关系,所以它的战术主要表现在增减杠铃的重量上,这样就出现了下列主要几种情况：     

举重与杠铃练习

力量,在很多体育运动项目中是掌握技术和取得优异成绩和基础,在田径运动项目中,力量是诸身体素质中占有重要位置的素质。因而人们都很重视力量训练。在田径训练中,人们为了发展力量,特别是投掷运动员,经常采用杠铃练习,认为这是发展力量行之有效的的手段,在训练实践中,也确实取得了良好的效果。然而,为了更好地提高练习效果,我认为,有一个问题急需解决。即:田径训练中的杠铃练习与举重运动中的举杠铃练习,在动作结构和技术要求上是否相同的问题。通过对杠铃练习的大量观察发现:当前许多练习者都是采用举重的办法进行杠铃练习的。就是当练习者在上举杠铃     

排球运动员弹跳力与力量素质多种能力相互关系的定量分析

运用三维测力台系统和红外光点运动分析系统同步测试的方法,定量测试分析运动员杠铃负重量半蹲练习过程中,人体对地面的跨伸力、对杠铃的作功率和杠铃在人体作用下运动的加速度、末速度、动量等参数指标与负荷重量的相互关系;及各参数指标的最大值与弹跳力的相关关系。为继不同训练水平的运动员发展弹跳力的力量素质训练内容的定向化、负荷重量的定量化提供了科学的理论依据。     

Patterns of barbell acceleration during the snatch in weightlifting competition

The purpose of this study was to determine the association between weightlifting performance and vertical barbell acceleration patterns. Barbell kinematic time-series data were tracked from 18 snatches from six weightlifters during a regional weightlifting competition. These data were used to calculate vertical barbell accelerations. Time-series data were normalised to 100% of lift phase, defined as the time interval between barbell lift-off and maximum height of the barbell during each snatch lift. The time-series data were then entered into a pattern recognition algorithm that extracted principal patterns and calculated principal pattern scores. Body mass-normalised lift weight, which was used to quantify weightlifting performance, was significantly correlated (r = 0.673; P = 0.033) with a pattern that captured a difference in peak vertical barbell acceleration between the transition and the second pull phase. This correlation indicated that barbell acceleration profiles of higher weight snatch lifts were characterised by smaller decreases in acceleration during the second knee bend and smaller peak acceleration during the second pull phase. Weightlifting coaches and sports scientist should monitor and track vertical acceleration of the barbell, with focus on acceleration profiles that limit (1) deceleration during the transition phase between the first and second pull and (2) peak acceleration during the second pull phase of the snatch.     

Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training

Abstract

The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m·s^?1 (～60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤0.80 m·s^?1). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.     

陈艳青备战北京奥运会专项辅助练习与竞赛成绩关系研究

采用文献资料、数理统计等方法,研究2004年雅典和2008年北京两届奥运会女子举重58公斤级冠军陈艳青在备战北京奥运会期间的主要辅助练习和竞赛成绩之间的关系。结果显示:主要专项辅助动作成绩与竞赛动作成绩具高度显著性相关;宽拉、后蹲成绩共同作用影响抓举成绩;借力推、高翻混挺、垫木窄硬拉成绩共同作用影响挺举成绩;陈艳青在训练内容的选择上有其明显的特点。     

The reliability of accelerometry to measure weightlifting performance

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.     

Validity and reliability of a computer-vision-based smartphone app for measuring barbell trajectory during the snatch

ABSTRACT

The purpose of this study was to investigate the validity of a smartphone app to measure biomechanical barbell parameters during the snatch. Ten collegiate NCAA division I athletes performed two repetitions each at 40, 50, 60, 70, and 80% of their 1-repetition maximum snatch. Barbell motions were simultaneously recorded with a motion capture system and the smartphone app. The motion capture system recorded the 3-D position of a reflective marker attached to the end of the barbell while the smartphone app was used to record sagittal plane video and track the shape of the weight plate from which the barbell center was derived. Peak forward (PFD) and backward (PBD) displacements and peak vertical displacement (PVD) and velocity (PVV) were calculated from both sets of data. Significant, strong to very strong Pearson’s product-moment correlation coefficients between both systems were noted for all parameters (r = 0.729–0.902, all p < 0.001). Small significant biases between systems were observed for PVD (ES = 0.284, p < 0.001) and PFD (ES=0.340, p < 0.01), while trivial to small, non-significant biases were observed for PBD (ES = 0.143) and PVV (ES = –0.100). Collectively, the results suggest that the app can provide biomechanical data of barbell motions similar to a 3-D motion capture system.     

Distribution of lower extremity work during clean variations performed with different effort

The purpose of this research was to investigate how lower extremity work was distributed during the pull of cleans performed lifting the barbell to the minimum height required to receive it in a full squat (minimal height clean); or with maximum effort to elevate the barbell as high as possible and receiving it in either a full (maximal effort clean) or partial (power clean) squat. Eight weightlifters screened for proficient technique performed these clean variations at 80% of one repetition maximum. Work performed on the barbell and by the lower extremity net joint moments (NJM) was computed from marker trajectories and ground reaction forces. Total barbell work, lower extremity NJM work, knee extensor work, and knee joint excursion during the second pull was lower in the minimal height clean than the maximal effort and power cleans (P < 0.05). This research demonstrates that more knee extensor work is performed in the second pull of maximal effort and power cleans compared to the minimal height clean. The larger knee extensor work performed is due to larger knee joint excursion during the second pull of the maximal effort and power cleans, but not larger knee extensor NJM.     

The influence of deformation on barbell mechanics during the clean pull

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.     

The influence of deformation on barbell mechanics during the clean pull

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.