The influence of deformation on barbell mechanics during the clean pull     

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   

湖南省竞技举重后备人才培养现状研究     

申再林  宋跃先 《湖北体育科技》2013,32(6):512-514,525

采用文献资料、问卷调查、实地调查、专家访谈、比较分析等方法对湖南省举重管理中心、举重基地、体校的二、三线运动员、教练员等进行调研。结果显示:湖南省竞技举重后备人才培养模式有其特点;省二线队伍很少,主要分布在经济条件差的边缘市县,总体竞技实力位于全国第1集团中上游水平,男子优势明显;教练员的人数、职称、学历总体合理,科研能力不强;人才流动渠道不畅通、省体育学校的承启作用未能充分发挥,束缚了举重的正常发展。  相似文献   

A biomechanical comparison of the vertical jump,power clean,and jump squat     

Sasho James MacKenzie  Robert J. Lavers  Brendan B. Wallace 《Journal of sports sciences》2013,31(16):1576-1585

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Student Interest in Activities in a Secondary Physical Education Curriculum: An Analysis of Student Subjectivity     

Peggy A. Fitzsimmons  Daniel M. Landers  Jerry R. Thomas  Hans van der Mars 《Research quarterly for exercise and sport》2013,84(4):424-431

Abstract

Previous studies that have examined self-efficacy–performance relationships have used novice performers. It is unclear if these findings would generalize to “experienced” performers. Based on Bandura's self-efficacy theory, this study was designed to investigate (a) the effects of false information feedback on self-efficacy beliefs and subsequent weightlifting performance, and (b) whether self-efficacy or past performance is most related to subsequent weightlifting performance. Experienced weightlifters engaged in six performance sessions, each consisting of a one-repetition-maximum bench press. Male subjects (N = 36) were randomly assigned to one of three treatment groups: accurate performance information, false information that they lifted more than their actual lift, or false information that they lifted less than their actual lift. Before each session, subjects indicated the amount of weight they were 100%, 75%, and 50% confident they could lift. Results replicated existing research findings regarding deception and performance; false positive feedback increased future bench press performance. In addition, results indicated that past weightlifting performance accounted for nearly all of the variance in subsequent performance. This finding is discussed in light of the difficulty in extending the predictions of self-efficacy theory to sport settings where athletes have gained experience by undergoing repeated training trials.  相似文献   

The effect of elevating the heels on spinal kinematics and kinetics during the back squat in trained and novice weight trainers     

Mark G. L. Sayers  Caroline Bachem  Pascal Schütz  William R. Taylor  Renate List  Silvio Lorenzetti 《Journal of sports sciences》2020,38(9):1000-1008

ABSTRACT

This research assessed the influence of various heel elevation conditions on spinal kinematic and kinetic data during loaded (25% and 50% of body weight) high-bar back squats. Ten novice (mass 67.6 ± 12.4 kg, height 1.73 ± 0.10 m) and ten regular weight trainers (mass 66.0 ± 10.7 kg, height 1.71 ± 0.09 m) completed eight repetitions at each load wearing conventional training shoes standing on the flat level floor (LF) and on an inclined board (EH). The regular weight training group performed an additional eight repetitions wearing weightlifting shoes (WS). Statistical parametric mapping (SPM1D) and repeated measures analysis of variance were used to assess differences in spinal curvature and kinetics across the shoe/floor conditions and loads. SPM1D analyses indicated that during the LF condition the novice weight trainers had greater moments around L4/L5 than the regular weight trainers during the last 20% of the lift (P < 0.05), with this difference becoming non-significant during the EH condition. This study indicates that from a perspective of spinal safety, it appears advantageous for novice weight trainers to perform back squats with their heels slightly elevated, while regular weight trainers appear to realize only limited benefits performing back squats with either EH or WS.  相似文献   

海峡两岸举重运动员营养调查报告     

黄明强 《中国体育科技》2001,37(3):41-43

采用问卷调查法，对海峡两岸举重运动员的营养概念、饮食习惯及训练后对食品的特殊需要进行研究。结果表明，海峡两岸举重运动员营养观念不同，饮食习惯带有地区特色，有不良饮食嗜好，训练后补充饮料欠科学。现阶段对海峡两岸举重运动员应大力实施营养干预措施，建立科学、合理的运动员膳食制度，形成良好饮食习惯，以提高运动技术水平，促进两岸体育文化的交流和发展。  相似文献   

利用超声心动图对优秀举重运动员和无训练青年安静时左心形态功能的对比研究     

董萍  陈翔宇 《沈阳体育学院学报》1996,(4)

通过对举重运动员和无训练一般正常青年人的超声心动图（Ｕ·Ｃ·Ｇ）的分析，探讨长期从事举重训练对运动员左心形态和功能的影响，同时尝试对其机理加以探讨。  相似文献   

论举重运动员战术意识的培养     

王红英 《体育科学研究》2001,5(3):72-75

分析了举重比赛的主要特点,强调了举重运动员只有具备了良好的战术意识,才能达到最佳竞技状态,充分发挥已有的技术水平,甚至是超水平的发挥.据此提出了一整套战术意识培养的途径和方法.  相似文献   

广西男子举重队的成绩分析     

单信海 《体育科技》2005,26(1):21-23

通过对2 0 0 4年全国男子举重锦标赛暨奥运会选拔赛的成绩分析,认为广西队有如下特点:广西取得了金牌与奖牌数两个第一,处于全国领先位置;广西在小级别传统强项上继续保持着较高水准,同时又在某些中级别上有所突破;一挺的整体成功率比较高,但个别运动员存在三次试举全部失败的现象,今后训练中要努力改进。  相似文献   

举重运动员腰肌末端病的发病特点和治疗   总被引：1，自引：0，他引：1  

徐明  赵常修 《体育科研》1996,(4)

通过对上海市举重队患有腰肌末端病症状的20余名运动员进行约1500次治疗的总结,提出腰肌高张力是举重运动员腰肌末端病发病的重要原因。腰肌高张力下的疼痛是末端病的主要表现和诊断的重要依据。概括出有效的治疗方法和较适用于训练比赛实际的针灸疗法。  相似文献