共查询到18条相似文献，搜索用时 187 毫秒
1.
等速运动过程中肌放电量与肌氧含量的变化特征 总被引：7，自引：0，他引：7
利用表面肌电图和近红外线光谱测定技术(NIRS),在30%和50%肘关节最大性力量(MVC)两种负荷条件下,对肘关节等速运动状态下的肱二头肌和肱三头肌的肌放电量及其肌肉组织内部血红蛋白和肌红蛋白含量(oxy-Hb·Mb)的变化进行了观察.结果表明:在运动过程中肌放电量和oxy-Hb·Mb均有明显的逐步下降和表面肌电图的积分值(iEMG)逐渐升高现象,而且50%MVC组下降幅度大于30%MVC组;iEMG和oxy-Hb·Mb的变化具有明显的相关性.因此可以认为,NIRS和表面肌电图作为特异性良好的非创伤性检测手段,能够直观地反映运动中肌肉内氧的代谢与骨骼肌的收缩活动. 相似文献
2.
运动性肌肉疲劳过程中主动肌与拮抗肌sEMG相干性分析 总被引：3，自引：1，他引：2
目的:通过静态疲劳负荷实验过程中主动肌与拮抗肌sEMG的相干性分析探索运动性肌肉疲劳过程中中枢神经系统对主动肌与拮抗肌共神经输入(common neural inputs)同步支配的变化特征。方法:以10名健康男性青年志愿者为研究对象,记录受试者以50%MVC负荷强度静态屈肘运动诱发肌肉疲劳过程中主动肌肱二头肌与拮抗肌肱三头肌的sEMG,为考查疲劳因素对相干性分析结果的影响作用,对记录的sEMG按运动持续时间平均分为两段,分别对两段sEMG进行相干性分析处理。结果:在疲劳负荷实验过程中,肱二头肌与肱三头肌MF指标随运动持续时间表现出显著性的单调递减变化趋势。从相干性分析结果看,在beta频段和gamma频段内,运动后半段肱二头肌与肱三头肌sEMG相干函数值要明显小于运动前半段,而tremor频段内无显著性差异。结论:在50%MVC静态负荷屈肘运动致肌肉疲劳过程中,随着负荷运动持续时间的增加,中枢神经系统对主动肌肱二头肌与拮抗肌肱三头肌共神经输入同步支配下降,这可能是由于主动肌与拮抗肌脊髓运动神经元兴奋性及运动皮层对脊髓运动神经元激活能力随疲劳发展的下降不同步性及为维持既定的收缩负荷,中枢神经系统对主动肌与拮抗肌运动单位的募集策略采取不同的调节方式造成的。 相似文献
3.
《体育科技文献通报》2004,(12)
G804.2不同负荷强度运动时表面肌电图中位频率与血乳酸浓度变化的关系=Relation between changes 0f sEMG's[mean frequency and changes of blood laetatecontent with different loads during exercise[刊,中,A]/王国祥(苏州大学)∥体育学刊.-2004,11(1).-45-48图5表1参11(SJ)强度训练∥肌电图∥频率∥血乳酸∥浓度∥关系 采用等速运动方式,以表面肌电图和血乳酸为指标,在10％、30％和50%,MVC三种负荷条件下,对肘关节屈伸 相似文献
4.
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
5.
单侧肢体运动对对侧肌肉肌电频率的影响 总被引：3，自引：1，他引：2
目的:研究单侧肢体动态运动诱发肌肉疲劳对对侧肌肉肌电信号平均功率频率(MPF)的影响,验证MPF下降的中枢控制作用.方法:10名男性受试者一侧上肢(负荷臂)分别完成5kg持重动态运动负荷实验和无负重放松实验,记录另外一侧(观察臂)完成4kg持重等长运动实验时肱二头肌、肱三头肌和斜方肌的sEMG信号,考察负荷臂两种运动状态下观察臂肌肉肌电的MPF、平均肌电值、复杂度和有序性等变化的差异性.结果:5kg持重动态运动实验过程中观察臂肱二头肌、肱三头肌和斜方肌的MPF均值均显著低于无负重放松实验状态;肱三头肌MPF的下降斜率显著增加.结论:负荷臂动态运动诱发一侧肌肉疲劳过程中可以造成对侧观察臂肌肉平均功率频率产生伴随性变化,表明sEMG信号活动具有确切的中枢控制成分. 相似文献
6.
罗亮 《武汉体育学院学报》2011,45(1):55-59
研究优秀武术运动员无氧运动强度时肌电信号特征及其与血乳酸指标之间的相关性。研究对象为12名一级武术运动员和12名二级武术运动员。研究方法:肌电指标测试:两组受试对象负重体重的7.5%,在功率自行车上持续运动60s后记录运动中和运动后30s内肌电指标MPF、MF和IEMG;血乳酸测试:采集运动中(20s一次)和运动后3min内的血乳酸浓度。结论:两组受试对象的MPF和MF均呈线性下降,但是对照组下降的斜率始终大于试验组,表明对照组比试验组更容易疲劳;IEMG呈线性上升,随着时间的延长,斜率加大,并且试验组斜率始终大于对照组,表明实验组肌纤维的募集能力要强于对照组;各肌电图指标与血乳酸之间存在着高度的负相关,但是血乳酸的积累并不是引起肌电图指标变化的直接原因。 相似文献
7.
采集20个对象在进行手间距在40cm、60cm和80cm引体向上运动下的肱三头肌、肱二头肌和三角肌表面肌电信号,运用数理统计法进行处理与分析,比较三种不同手间距下的三块肌肉表面肌电信号的差异。双手的间距逐渐增加,所进行的引体向上对肱三头肌的刺激强度也随之增大。在手间距80cm进行引体向上时的肱三头肌表面肌电信号最强。手间距越大的反握引体向上对肱三头肌刺激最大。 相似文献
8.
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
9.
振动与非振动力量练习时肌电图变化的比较研究 总被引：16，自引：0，他引：16
采用芬兰的MuscleTesterME3000P8肌电图仪和MegaWin软件系统,让受试者在振动和非振动条件下,分别以动力性和静力性两种不同方式的进行屈肘练习,练习时施加不同的负荷,通过对受试者的肱二头肌、屈腕肌和对抗肌肱三头肌、伸腕肌的肌电图测试。结果表明,当负荷与肌肉收缩的方式相同时,振动条件下主动肌的肌电IEMG/s值都比非振动时大,而动力性收缩时,振动轻负荷与非振动重负荷时IEMG/s值相差不大。这说明,在振动条件下进行力量训练,能够募集更多的运动单位参与收缩,提高肌肉的兴奋水平。 相似文献
10.
我国优秀男子拳击运动员后手直拳击打环节相关肌群的EMG特征及其运动学分析 总被引：1，自引：0，他引：1
目的:研究我国优秀男子拳击运动员后手直拳出拳击打环节相关肌群的sEMG特征及其相应的运动学变化,为拳击专项力量训练提供参考.方法:通过表面肌电和三维红外高速摄像系统同步测试方法,采集6名高水平男子拳击运动员后手直拳出拳击打环节表面肌电和运动学的相关数据.结果:1)出拳击打环节,肌肉活动顺序为:腓肠肌→股二头肌→三角肌前束→肱三头肌→肱二头肌长头→肱桡肌.2)击打过程中三角肌前束、肱二头肌和肱三头肌肉在相应时间位置上出现明显的预激活和共收缩现象.3)肌肉做功百分比排序为:三角肌前束＞肱三头肌＞股二头肌＞腓肠肌＞肱桡肌＞肱二头肌长头,aEMG计算结果与肌肉做功百分比保持相一致的趋势.4)肩关节、上臂环节质心和拳心速度的峰值在击打过程中呈现次序性.结论:拳击后直拳出拳击打环节所选肌肉活动呈现从下肢向上肢激活的次序性.击打过程中三角肌前束、肱二头肌和肱三头肌肉在相应时间位置上出现的预激活和共收缩现象可能是反映运动员技术水平和特点的指标.在肌肉做功百分比和aEMG方面,三角肌前束、肱三头肌和股二头肌在动作过程中表现出相对重要的地位.上肢相关肌群的活动次序与肩关节、上臂环节质心和拳心速度变化的时序性有着合理的解剖学相关,是产生上肢开放链鞭打动作的根本原因. 相似文献
11.
间断递增负荷条件下肌肉活动的力-电关系 总被引：1，自引：0，他引：1
目的：探讨非疲劳状态下肱二头肌在静态间断性递增负荷下sEMG信号的线性扣非线性指标变化规律；方法：记录19名被试肱二头肌在10％、20％、40％、60％、80％MVC负荷水平下sEMG信号，分析线性时、频指标AEMG、MPF、MF和非线性指标C（N）、DET％的变化规律；研究结果：在负荷水平从10％上升到80％MVC过程中，线性分析指标AEMG、MPF和MF均呈单调递增性改变。非线性分析指标DET％呈单调递减性改变，C（N）基本保持稳定；结论：以上sEMG信号变化的原因可能与递增负荷运动过程中Ⅱ型肌纤维募集比例和数量的增加有关。 相似文献
12.
Tarak Driss Virgile Serrau David George Behm Ethelle Lesne-Chabran Armande Le Pellec-Muller Henry Vandewalle 《Journal of sports sciences》2013,31(1):60-69
AbstractThe 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
13.
研究目的：对长拳、太极拳冲拳动作进行肌电实验,分析长拳、太极拳完成冲拳动作时所调动的肌肉及其iemg值,得出在研究对象本身无差异情况下,不同拳术冲拳的发力对肌肉的调动情况。研究方法：在肌电实验中,以固定个体为研究对象,通过运用美国noraxon生产的t6无线导遥测肌电对练习长拳、太极拳冲拳时的上下肢肌肉表面肌电特征进行分析。研究结果：长拳冲拳过程中,肌肉活动顺序为腹直肌、三角肌前束、股内侧肌、股直肌、腹外斜肌、股外侧肌、股四头肌、肱三头肌、肱桡肌、竖脊肌;积分肌电显示在长拳冲拳阶段三角肌前束、肱桡肌的积分肌电最高;在整个长拳冲拳过程中,腹外斜肌的肌肉贡献率最大。太极拳冲拳过程中,肌肉活动顺序为肱桡肌、腹外斜肌、股内侧肌、竖脊肌、三角肌前束、腹直肌、股外侧肌、肱三头肌、腹直肌、股四头肌;积分肌电显示在太极拳冲拳阶段肱桡肌、股内侧肌的积分肌电最高;在整个太极拳冲拳过程中,腹内斜肌的机头贡献率最大。研究结论：长拳冲拳过程中,受试者较好完成技术动作,腹直肌首先放电,肌肉力量的发放大部分来源于肱桡肌、三角肌前束和肱三头肌,集中于上肢腰部和手臂。太极拳冲拳过程中,受试者未能掌握技术动作,肌肉发力顺序不符合太极拳冲拳技术要求。 相似文献
14.
《European Journal of Sport Science》2013,13(5):408-417
Abstract The aim of the present study was to investigate the patterns of shoulder muscle activation and joint torques during maximal effort eccentric contractions with shoulder extension, abduction, and diagonal movements on the isokinetic device. Participants in this investigation were nine men and four women with no history of shoulder injury or disorders. They all participated in overhead sports at least three days a week, and volunteered to participate in this study for shoulder isokinetic muscle strength testing. They performed eccentric muscle action with shoulder flexion, abduction, and diagonal movements at velocities of 60 rad·s?1 and 180 rad· s?1, which was followed alternately by passive shoulder flexion, abduction and diagonal movement at a velocity of 30 rad· s?1, and total range of motion was standardised to 90°. Electromyography (EMG) and torque values were calculated to every 10°, except for the start and end 5° during each task. During each test, the isokinetic force output and muscle activation were synchronised. EMG data were normalised by percentage of maximum voluntary isometric contraction (%MVIC). EMG signals were recorded by surface EMG from the anterior deltoid (AD), middle deltoid (MD), posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), and biceps brachii (BB) muscles during this test. All of the muscle patterns were significantly decreased at the last compared with the initial part during eccentric shoulder flexion movement, except for the BB muscle (P < 0.05). AD and BB muscles played a similar role when peak torque was generated under load during eccentric muscle action with varying shoulder movements. PD and UT muscle activities were significantly lower than the other muscle activities during eccentric contraction with shoulder flexion and abduction movements, and the PD and UT muscles played a significant role in conjunction with MD and MT muscles in varying degrees during eccentric contraction with shoulder diagonal movements at 180 rad·s?1 (P < 0.05). Our study demonstrated that MT muscle activity was greatly influenced when torque values showed a peak moment under load during maximum effort, eccentric contraction with shoulder abduction and diagonal movements. However, the MD, PD, UT, and MT muscle activities had no great influence when peak torque was generated under load during eccentric muscle action with shoulder diagonal movement at high velocity. The present study suggested that varying eccentric muscle activity patterns may be needed to investigate proper training and functional contributions of upper extremity muscles to stabilisation of the shoulder joint when peak torque was generated under load. 相似文献
15.
跳远运动员髋关节振动力量训练效果的研究 总被引：1，自引：1，他引：0
对10 名跳远专项二级运动员进行振动力量训练。研究表明：在刺激频率为30~35Hz,加速度25~30 m/s2 条件下,经过8 周系统的振动力量
训练,试验组髋关节的屈伸肌群与对照组屈肌肌群最大功增长都非常明显,表现出髋关节屈肌最大功比试验前有显著性地提高,试验组髋关节
屈伸肌最大功增长幅度比对照组屈伸肌最大功幅度大。试验组髋关节伸肌对照组屈伸肌峰力矩前4 周比后4 周增长幅度大,后4 周增长幅度有
所减缓,试验组后4 周髋关节屈伸肌峰力矩增长幅度比对照组高。髋关节伸肌相对峰力矩力量增长幅度比屈肌要大。 相似文献
16.
Jeffrey C. Ives Walter P. Kroll Linda L. Bultman 《Research quarterly for exercise and sport》2013,84(3):274-283
Abstract Maximally fast, self-terminated, elbow flexion movements were performed by 10 male and 10 female college-aged subjects to assess potential gender-related differences in kinematics and the triphasic electromyographic (EMG) pattern. The subjects were instructed to move their forearms as fast as possible through 90° of elbow flexion range of motion and stop as sharply as possible at the terminal point. An electromagnet, set to 0, 40, and 70% of each subject's maximal isometric torque, provided resistance to movement initiation and resulted in quick release movements. Surface EMG was collected from the biceps b. and triceps b. muscles. Results indicated that the males had faster movements and accelerations under all conditions. EMG records indicated that the males had faster rates of EMG rise, particularly in the triceps b., and more tightly coupled reciprocal activation. The quick release afforded faster accelerations for both groups, yet only the males moved faster throughout the full range of motion. Following the quick release, the males differed from the females by increasing the triceps b. EMG amplitude. Hence, the males were able to shorten movement time in quick release movements by increasing triceps b. activation and, thus, braking ability. These results suggest that the females were more neurally constrained than the males with respect to rapid EMG activation of the triceps b., resulting in limits in the braking process. 相似文献
17.
Yasuharu Nagano Ayako Higashihara Kazumasa Takahashi Toru Fukubayashi 《Journal of sports sciences》2013,31(18):1722-1728
AbstractWe aimed to demonstrate the changes over time in the lengths and forces of the muscles crossing the hip joint during overground sprinting and investigate the relationships between muscle lengths and muscle–tendon unit forces – particularly peak biceps femoris force. We obtained three-dimensional kinematics during 1 running cycle from 8 healthy sprinters sprinting at maximum speed. Muscle lengths and muscle–tendon unit forces were calculated for the iliacus, rectus femoris, gluteus maximus, and biceps femoris muscles of the target leg as well as the contralateral iliacus and rectus femoris. Our results showed that during sprinting, the muscles crossing the hip joint demonstrate a stretch-shortening cycle and 1 or 2 peak forces. The timing of peak biceps femoris force, expressed as a percentage of the running cycle (mean [SD], 80.5 [2.9]%), was synchronous with those of the maximum biceps femoris length (82.8 [1.9]%) and peak forces of the gluteus maximus (83.8 [9.1]%), iliacus (81.1 [5.2]%), and contralateral iliacus (78.5 [5.8]%) and also that of the peak pelvic anterior tilt. The force of the biceps femoris appeared to be influenced by the actions of the muscles crossing the hip joint as well as by the pelvic anterior tilt. 相似文献
18.
目的:通过对男大学生小腿三头肌在递增负重提踵和蹲跳动作时表面肌电(sEMG)信号的分析,探讨动作形式与神经肌肉活动方式之间的联系。方法:男大学生在不负重和30%、60%、80%、100%最大力量(1RM)负重下分别进行一次提踵和蹲跳动作,同时记录腓肠肌内侧头(GM)、外侧头(GL)和比目鱼肌(SO)向心收缩阶段的sEMG信号,比较各等级负重条件下两种动作运动时iEMG、MF和MPF等肌电指标的变化。结果:在进行负重提踵时,随着重量增加,GM、GL和SO表面肌电的iEMG均显著增加,但MF和MPF在不同负重等级完成动作时的差异不显著;在进行负重蹲跳时,各肌肉表面肌电信号的iEMG、MF和MPF在各级负重之间具有显著差异,其数值与重量的增加具有线性关系;在不负重提踵时各肌肉的iEMG值与蹲跳差异不显著,但大负重后显著高于蹲跳;MF和MPF值在不负重提踵时显著高于蹲跳,负重后其差异基本不显著。结论:在递增负重提踵和蹲跳动作时,小腿三头肌向心收缩阶段的sEMG信号表现存在差异,其所反映的神经肌肉控制方式不同,提示所完成动作的动力学特性如速度、多关节链等,可能会影响运动单位募集的方式。 相似文献