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1.
不同齿轮比训练时自行车运动员肌电图的研究   总被引:2,自引:1,他引:1  
探讨利用sEMG对自行车运动员运动肌组织进行监测与机能分析的可行性。方法:8名自行车运动员进行42/15、52/12与52/15齿轮比练习台骑行测试,采用芬兰Muscle Tester ME3000P8肌电图仪与MegaWin软件系统记录分析运动时的sEMG值。结果表明:同侧同部位肌组织不同齿轮比练习时IEMG/s值不同,除小腿三头肌(P<0.05)外,各部位IEMG/s组间无显著差异;相同训练条件下同部位肌组织左右腿IEMG/s个体差异明显,提示sEMG能够直观反映动力性运动中肌肉的收缩活动,不同齿轮比骑行对下肢不同部位骨骼肌刺激不同。建议:训练监控中,sEMG适合应用于运动员个体的纵向比较。  相似文献   

2.
张立  宋高晴 《体育科学》2006,26(3):53-57
研究目的:1)研究静力和动力性肌肉运动疲劳时肌肉氧含量的变化特点厦其规律;2)了解静力性、动力性递增强度运动时EMG参数变化;3)探讨肌氧含量与EMG参数变化之间的关系,为肌肉疲劳时影响肌电肌氧机制提供可能的理论基础。研究方法:1)肌氧含量的测试:探头纵向旋转让光源和检测器的轴线平行于股外侧肌外侧头大腿测定运动时肌氧含量的变化;2)肌电的测试:采用表面肌电图的测量,得出表面电图各指标参数;3)静力负荷等长收缩:通过力量传感器测出其最大肌肉收缩所对应的MVC;4)动力性负荷运动:采取功率自行车逐级递增负荷的测试方法作为肌肉的动力性运动,同步记录EMG参数,并在每一级负荷朱30S采血测定血乳酸浓度。结论:静力性运动时E/T值大幅度增大的时间大多出现在肌氧停止下降之后,肌氧的降低程度与肌肉疲劳程度有关。动力性运动时血乳酸值随负荷而增加,IEMG的变化趋势与血乳酸相似,IEMG、Oxy-Hb、BI值三者呈非常显著性相关,表明肌肉疲劳时肌肉氧供和内环境的改变也是影响EMG信号的重要因素。  相似文献   

3.
为测定并分析不同运动能力受试者在动力和静力性运动时肌肉运动疲劳过程中肌电和脑电信号变化特征,将20名受试者分为两组,经常运动组(A组)10名,运动不足组 10名(B组).受试者进行动力性MVC持续肌肉收缩和1/3MVC静力性持续收缩两种运动,同步记录EMG和EEG信号.结果显示,MVC动力性运动时A组受试者平均MVC、RMS、IEMG显著性大于B组,MF则呈下降.随肌肉收缩持续IEMG变化形成一明显的转折点,但1/3MVC静力性运动时肌肉持续收缩时间短于MVC运动时间.不管是动力还是静力运动IEMG拐点与脑电α指数拐点发生在时间上一致.结论:IEMG形成的拐点可能成为肌肉疲劳的参照点.EEG所反映的中枢疲劳与EMG所反映的外周疲劳在生物电学变化上具有共性特征.  相似文献   

4.
积分肌电对青年男子股四头肌的疲劳评价   总被引:6,自引:0,他引:6  
对30名青年男子按不同负荷进行下肢运动至疲劳的肌电图进行全程监测,通过对不同阶段IEMG进行分析处理,旨在探讨利用表面肌电图对受训肌肉进行监测和机能分析的可行性。结果发现,在使用IEMG,变化比例评定负荷程度和疲劳状态时应以运动初期肌电达到稳定状态的结果为基础。在双侧肌肉同时进行力量练习时,若着重发展弱势腿力量应采用中小训练强度,而采用大强度的训练刺激增加优势腿力量。  相似文献   

5.
王国祥 《体育学刊》2004,11(1):45-48
采用等速运动方式 ,以表面肌电图和血乳酸为指标 ,在 10 %、3 0 %和 50 %MVC三种负荷条件下 ,对肘关节屈伸运动时的肱三头肌、肱二头肌和前腕骨肌的表面肌电图和血乳酸浓度的变化进行了比较分析。结果表明 :(1)肘关节屈伸运动时 ,伸展运动的力矩峰值下降幅度大于屈曲运动。 (2 )以 3 0 %和 50 %MVC负荷强度运动时 ,出现了表面肌电图的MF值逐步下降和血乳酸浓度逐渐增加的现象 ;工作肌群MF下降幅度 ,由大到小依次为肱三头肌 >肱二头肌 >前腕骨肌。 (3 )肱三头肌、肱二头肌和前腕骨肌的表面肌电图的MF变化与血乳酸浓度变化相互比较 ,10 %、3 0 %和 50 %MVC三种运动形式都表现出了非常明显的相关性。实验结果可以说明 ,sEMG作为特异性良好的非损伤性检测手段 ,不但能够直观地反映肌肉的收缩活动 ,还与肌肉组织代谢变化有一定的相关关系  相似文献   

6.
目的:探讨不同把手类型自行车在不同坡度路面骑行时上肢肌群的用力变化特征,为自行车专业选手和骑行爱好者针对性专项训练或比赛, 以及动感单车制造商标注器材使用方法和锻炼效果提供科学理论参考。方法:8名健康男性大学体育专业志愿者,骑行不同把手类型(下弯型、平直 型和上翘型)的自行车,分别在模拟下坡4°和上坡4°地面上以60 rpm的转速行驶,阻力设定为功率120 W,检测骑行者上肢相关肌群(身体右侧的腕 伸肌、腕屈肌、肱二头肌、肱三头肌、三角肌、斜方肌、背阔肌)表面肌电平均振幅。结果:双因素方差分析显示,把手类型对骑行者腕屈肌、肱二头肌、 肱三头肌、三角肌和背阔肌AEMG有显著影响(P<0.05);坡度对骑行者腕伸肌、肱二头肌、三角肌和背阔肌AEMG有显著影响(P<0.05);把手类型和 坡度除了三角肌AEMG存在显著交互作用外(P<0.007),其余各被检上肢肌群AEMG均无显著交互作用。结论:平直型把手可以显著提高腕屈肌肌 肉激活;上翘型把手在上坡4°条件下可以显著提高肱二头肌和背阔肌的肌肉激活;下弯型把手可以显著提高肱三头肌和三角肌的肌肉激活,但要视 坡度情形而定;坡度增加可以显著提高骑行者腕伸肌、肱二头肌和背阔肌的肌肉激活。  相似文献   

7.
目的:采用表面肌电信号(Surface Electromyographic Signal,sEMG)分析技术研究不同负荷水平颈部两侧头夹肌、胸锁乳突肌和斜方肌上部肌肉等长收缩对相关肌肉平均肌电((Average EMG,AEMG)活动的影响,为进一步开展颈部肌肉功能和康复训练效果评价提供科学依据。方法:16名无颈部疾病的健康青年男性志愿者,分别在颈椎屈曲、后伸、左侧屈和右侧屈4个运动方向上完成20%最大随意收缩力(Maxi mal Voluntary Contraction,MVC)、40%MVC、60%MVC、80%MVC和100%MVC的等长收缩实验,期间采集被检肌肉的sEMG信号,计算标准化的AEMG。结果:①受试者最大颈椎后伸力量显著大于颈椎屈曲、颈左侧屈及右侧屈力量,而后三者之间没有显著差异;②递增负荷水平等长收缩条件下与运动方向同侧的颈部肌肉出现收缩增强效应,而对侧拮抗肌表现出明显的共收缩现象;③运动方向和负荷水平均对各被检肌肉的AE-MG有明显作用,且以上两因素对各被检肌肉AEMG有明显交互作用。结论:人体颈部最大伸颈力量显著大于屈颈、颈左侧屈和右侧屈力量,完成矢状面屈伸和额状面侧屈运动时各被检肌肉的AEMG值与负荷水平成正比。  相似文献   

8.
文烨 《中国体育科技》2012,48(4):71-77,89
目的:研究优秀乒乓球运动员和普通在校大学生肘关节拮抗肌活动在等动屈伸过程中的差异。方法:以8名优秀乒乓球运动员和8名普通高校大学生为研究对象,利用Biodex等动测试仪和Noraxon表面肌电仪记录上肢肘关节等动屈伸过程中作为拮抗肌的肱二头肌和肱三头肌的力量特征和表面肌电信号特征。肘关节伸肌和屈肌分别在最大等长收缩、15°/s、30°/s、60°/s、120°/s、180°/s、240°/s条件下进行3次最大等动离心屈伸运动。以标准化的均方根振幅(RMS)和标准化的峰值力矩作为评价指标。结果:对于大学生和优秀乒乓球运动员来说,随着肘关节速度的增加,两组受试者的屈伸肌力矩都呈下降趋势,大学生表现为速度大于60°/s时伸肌力矩大于屈肌力矩(P<0.05),优秀乒乓球运动员表现为伸肌力矩低于屈肌力矩,但没有统计学差别(P>0.05)。大学生和优秀乒乓球运动员都表现为在向心收缩时不同速度下随着主动肌力矩下降,拮抗肌激活水平表现为逐渐增高,且所有线性拟合系数r2>0.7。优秀乒乓球运动员拮抗肌肱三头肌的激活水平(在MVC时:10.1%±5.2%,240°/s时:15.1%±6.6%)要显著低于普通高校大学生(MVC时:29.3%±8.8%,240°/s时:38.0%±15.1%)。而作为拮抗肌的肱二头肌激活水平在普通大学生和优秀乒乓球运动员之间没有统计学差异(P>0.05)。优秀乒乓球运动员拮抗肌/主动肌肌电活动比要显著低于普通大学生(P<0.05)。结论:与普通大学生相比,优秀乒乓球运动员肘关节拮抗肌肱三头肌的激活水平要更低,这可能是优秀乒乓球运动员对肘关节周围肌肉进行长期训练的结果。而两者拮抗肌肱二头肌激活水平没有统计学差异,其原因可能是由于两者在日常活动中肱二头肌作为拮抗肌经常为了克服地心引力受到同样的刺激造成的。  相似文献   

9.
不同形式肌肉收缩时肌电参数变化特征及机制   总被引:1,自引:1,他引:0       下载免费PDF全文
研究目的:探讨动力性与静力性肌肉收缩时EMG各参数的变化特征及疲劳时各指标的差异,比较不同项目运动员肌肉收缩特征对EMG参数的影响及与该项目的关系。研究方法:27名受试者分为两组,第一组为赛艇运动员(组一),第二组为田径爆发性力量项目(跳跃、短跑)专选运动员(组二)。受试者以2/3Mvc做静力性持续等长收缩,动力性持续肌肉收缩则采用本人的MVC,同时记录EMG信号,分析IEMG、E/T值和MF。研究结果:持续静力性肌肉收缩时,随疲劳的发展赛艇运动员与田径运动员IEMG、E/T值均显著升高。但赛艇运动员从运动开始至80%时段一直保持平稳,此后迅速上升。静力性收缩时两组运动员随疲劳发展MF从高频向低频转移,但田径运动员频率下降速率要快于赛艇运动员。结论:赛艇运动训练促使大脑皮层动员运动单位工作更具有时间耐久性。快速、爆发式运动使疲劳时大脑皮层兴奋性下降更快,肌肉更易于疲劳。  相似文献   

10.
G871.03,HL006 9903277对射击运动员抗干扰时肌紧张变化规律的研究[HL,中.A]/张百鸣∥第五届全国体育科学大会论文摘要汇编.-1997.-431-432(XG)射击∥抗干扰∥肌肉∥紧张∥EMG∥心理∥影响因素通过对受试者右肘伸肌群在负重及放松时 EMG 水平的监测,观察受试者在安静条件下与外界干扰条件下的 EMG 变化规律来研究射击运动员抗干扰时肌紧张变化规律。对受试者进行了协调性实验和放松实验,在协调性实验中要求受试者在右肘屈肌负荷10公斤的紧张收缩状态下努力放松右肘伸肌群,放松实验要求  相似文献   

11.
Abstract

Non-local muscle fatigue has been demonstrated with unilateral activities, where fatiguing one limb alters opposite limb forces. Fewer studies have examined if non-local fatigue occurs with unrelated muscles. The purpose of this study was to investigate if knee extensors fatigue alters elbow flexors force and electromyography (EMG) activity. Eighteen males completed a control and fatiguing session (randomised). Blood lactate was initially sampled followed by three maximal voluntary contractions (MVC) with the elbow flexors and two with the knee extensors. Thereafter, subjects either sat (control) or performed five sets of bilateral dynamic knee extensions to exhaustion using a load equal to the dominant limb MVC (1-min rest between sets). Immediately afterwards, subjects were assessed for blood lactate and unilateral knee extensors MVC, and after 1 min performed a single unilateral elbow flexor MVC. Two minutes later, subjects performed 12 unilateral elbow flexor MVCs (5 s contraction/10 s rest) followed by a third blood lactate test. Compared to control, knee extensor force dropped by 35% (p < 0.001; ES = 1.6) and blood lactate increased by 18% (p < 0.001; ES = 2.8). Elbow flexor forces were lower after the fatiguing protocol only during the last five MVCs (p < 0.05; ES = ~0.58; ~5%). No changes occurred between conditions in EMG. Elbow flexor forces significantly decreased after knee extensors fatigue. The effect was revealed during the later stages of the repeated MVCs protocol, demonstrating that non-local fatigue may have a stronger effect on repeated rather than on single attempts of maximal force production.  相似文献   

12.
通过录像观察法、实验测试法,利用德国Isomed 2000等速力量测试系统对男子速射和男子慢射运动员右侧肩关节、肘关节、腕关节依次进行角速度为60°/s等速向心肌肉力量测试,选取屈肌肌群、伸肌肌群的相对峰力矩和相对峰值功率为指标,对手枪男子速射和慢射项目运动员的上肢肌肉力量进行了研究,比较分析了男子速射和男子慢射肩、肘、腕关节屈伸肌群的肌力特征。发现肘关节伸肌肌群、腕关节屈肌肌群分别为速射和慢射影响最大的关节肌群。  相似文献   

13.
Abstract

The present investigation verified that strength is improved by a training programme consisting of repetitions of maximal isometric voluntary co-contractions without increasing co-activations during contractions against external resistances. Ten participants performed 12 training sessions (four sets of 6 × 4 second maximal isometric co-contraction of the elbow flexor and extensors, 3 days a week for 4 weeks). Surface electromyograms of triceps and biceps brachii were collected during maximal voluntary isometric elbow flexion and extension against a force transducer. Maximal voluntary isometric force increased significantly after training, by 13.8 ± 6.0% (extension) and 9.6 ± 9.5% (flexion), but the observed increases in EMG of agonist muscles during maximal voluntary contraction were not significant. No significant changes in the levels of co-activation of the elbow flexors and extensors were observed. No significant change was observed for all the parameters in a control group of ten participants. These results indicated that the strength improvements after co-contraction training occur without increases in co-activation level.  相似文献   

14.
运用等速测试系统对备战伦敦奥运会的国家划艇运动员的肩关节、肘关节肌力进行测试与分析。结果表明:1)从力矩角度来看,优秀运动员与一般运动员在肩、肘关节肌力特征中存在显著性差异(P<0.05),且屈肌和伸肌的力矩角度分别呈现不同的特征;2)从峰力矩比值来看,在不同速度运动下,国家队优秀运动员和一般运动员均存在屈伸比的失衡问题,即最大力量上存在屈伸肌群发展的不合理化现象(<50%),随着测试速度的增加,屈伸比呈递减趋势;3)在肘关节两侧同名肌群的比较中同样存在不均衡现象,尤其是伸肌的两侧差值较大;4)肩关节的肌力特征也存在类似的现象,但屈肌明显不如伸肌力量。结论:应逐步加强划艇运动员肩、肘关节同侧屈伸肌群和异侧同名肌群的力量均衡性训练,并提高肩关节的屈肌力量能力。  相似文献   

15.
运用表面肌电遥测和高速摄像同步测试方法,揭示我国部分高水平短跑运动员途中跑摆动技术的肌肉用力特征。结果表明:短跑途中跑摆动技术的肌电特征表现为明显的时序性,肌肉间的收缩具有高度协调性。折叠前摆阶段,摆动腿屈髋肌的主要电位活动是在摆动初期:运动员足蹬离地面至(另一腿)垂直支撑时刻前;垂直支撑时刻后,摆动腿股二头肌长头、半腱肌的活动明显,活动时间较长;下压着地阶段,其工作性质由被动拉长转为向心收缩使髋关节伸,同时还作用于膝关节使膝关节屈,神经肌肉活动的机制十分复杂。在专项力量训练实践中,教练员应结合摆动腿髋关节屈伸肌群的发力特点,优选专项力量训练的手段,提高训练效果。  相似文献   

16.
The purpose of the study was to investigate the effect of different kicking modality, i.e., erratic-dynamic target (EDT) versus static target (ST) on the performance of the roundhouse kick in two groups of taekwondo athletes of different skill level. Three-dimensional analysis and surface electromyography (SEMG) analysis were performed on 12 (Group A: six sub-elite, Group B: six elite) athletes to investigate muscle co-activation pattern under two conditions, i.e., EDT versus ST. In the results, the muscle recruitment ratio of the agonistic muscles was higher for Group A, whereas Group B had higher recruitment ratio for antagonist muscles. Overall, the co-activation index (CI) of hip joints appeared higher in the extensors for Group A, whereas higher CI was observed in flexor muscles for Group B with comparatively higher CI during EDT condition than ST condition. Higher value of CI was observed in flexor muscles of the knee joints among Group A during EDT conditions, in contrast, higher CI in the extensor muscles was observed among Group B during ST conditions. In conclusion, the study confirmed that erratic-dynamic movements of target could change the movement coordination pattern to maintain the joint stability of participants.  相似文献   

17.
青年男子举重运动员肘关节屈伸肌群等速肌力特征   总被引:1,自引:0,他引:1       下载免费PDF全文
檀志宗 《体育科研》2009,30(1):75-77
通过分析青年男子举重运动员肘关节屈伸肌群的力量参数,探讨肘关节屈伸肌群在举重专项训练中的作用,为预防肘关节损伤及科学训练提供理论依据。采用Cybex—Norm型等速测力与康复系统,在预定角速度90°/s.180°/s和300°/s下对上海举重队9名青年男子举重运动员肘关节进行等速向心屈伸肌力测试。结果发现举重运动员肘关节屈伸肌群相对峰力矩、相对总劝和相对平均功率随着运动速度的增大而减小,屈伸肌群峰力矩比值接近1.0。表明举重项目中肘关节屈伸肌群主要功能是维持运动中关节的稳定性,而两侧肘关节同名肌群肌力素质的不均衡性可能是阻碍专项能力韦黾高的重要因素和诱发运动性伤病的潜在因素。  相似文献   

18.
Abstract

The study investigated different electromyographic (EMG) normalisation methods for upper-limb muscles. This assessment aimed at comparing the EMG amplitude and the reliability of EMG values obtained with each method. Eighteen male tennis players completed isometric maximal voluntary contractions and dynamic strength exercises (push-ups and chin-ups) on three separate test sessions over at least 7 days. Surface EMG activity of nine upper body muscles was recorded. For each muscle, an analysis of variance for repeated measures was used to compare maximal EMG amplitudes between test conditions. The intra-class correlation coefficient, the coefficient of variation and the standard error of measurement were calculated to determine the EMG reliability of each condition. On the basis of a compromise between maximal EMG amplitude and high reliability, the chin-ups appeared to be the optimal normalisation method for M. latissimus dorsi, M. posterior deltoid, M. biceps brachii, M. flexor carpi radialis and M. extensor carpi radialis. The push-ups seemed relevant to normalise M. anterior deltoid and M. triceps brachii activity, while isometric maximal voluntary contraction remained the most appropriate method for M. pectoralis major and M. middle deltoid. Thus, original methods are proposed to normalise EMG signal of upper-limb muscles.  相似文献   

19.
This study investigated the contribution of flexor muscles to the forearm through fatigue; therefore, the differences in forearm mechanisms on the pitching motion in fastball were analysed. Fifteen baseball pitchers were included in this study. Ultrasonographical examination of participants’ ulnar nerve in the cubital tunnel with the elbow extended and at 45°, 90° and 120° of flexion was carried. A three-dimensional motion analysis system with 14 reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the flexor carpi ulnaris, flexor carpi radialis and extensor carpi radialis muscles of the dominant arm. Flexor carpi ulnaris muscle activity showed a significant difference during the acceleration phase, with a peak value during fastball post-fatigue (= 0.02). Significant differences in the distance between ulnar nerve and medial condyle on throwing arm and non-throwing arm were observed as the distance increased with the elbow movement from 0° to 120° of flexion (P = 0.01). The significant increase of the flexor carpi ulnaris muscle activity might be responsible for maintaining the stability of the wrist joint. The increased diameter might compress the ulnar nerve and cause several pathological changes. Therefore, fatigue in baseball pitchers still poses a threat to the ulnar nerve because the flexor carpi ulnaris and flexor carpi radialis all originate from the medial side of the elbow, and the swelling tendons after fatigue might be a key point.  相似文献   

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