不同形式肌肉收缩时肌电参数变化特征及机制

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。     

不同级别、不同水平男子赛艇运动员2000m测功仪比赛节奏策略的分析

目的:分析了不同级别、不同水平男子赛艇运动员2 000 m测功仪比赛时节奏策略的特点和差别。方法:以2008年、2009年英国室内赛艇锦标赛(比赛用时男子公开级<6min 4 s、男子轻量级<6 min 28 s)、中国国家赛艇队以及福建省赛艇队男子公开级(n=49)与轻量级(n=25)运动员2 000 m测功仪比赛每500 m分段速度作为研究对象,分别以运动水平和参赛级别作为数据分类的因素,根据分段相对速度比较其节奏策略的异同。结果:不同级别、不同水平男子赛艇运动员在启航节奏上无显著差异(P<0.05);途中划阶段公开级比轻量级相对速度下降更为明显(500~1 000 m:P<0.05;1 000~1 500 m:P<0.01),国家水平(500~1 000 m:P<0.05;1 000~1 500 m:P<0.01)和地区水平(500~1 000 m:P<0.01;1 000~1 500 m:P<0.01)比国际水平相对速度下降更为显著;终点划阶段,除国际水平公开级运动员的相对速度低于1 000~1 500 m段落(-0.75%)外,其余运动员的终点划相对速度均不同程度地高于1 000~1 500 m段落...     

皮艇运动员室内1 000m模拟划中表面肌电分析与应用

对8名武汉体育学院皮艇运动员在室内测功仪1 000m模拟划过程中,通过MEGA-6 000肌电仪实时监测,结果发现:(1)室内1 000m模拟划全程中,肱三头肌、背阔肌、肱桡肌、腹外斜肌是主要用力肌肉,在皮艇运动专项力量训练安排上,应着重加强这些肌肉的力量训练;(2)在判断1 000m模拟划全程的运动强度方面,IEMG变化与桨频的变化有很好的相关性,相关性系数r=0.664,具有非常显著性差异,表明表面肌电信号可以在一定程度上反映运动强度;(3)在完整周期动作的肌肉激活顺序方面,结合皮艇专项动作的解析,本研究中被测肌肉基本上遵循了正确技术动作的肌肉活动规律.     

优秀赛艇运动员测功仪2000m模拟比赛供能特征研究

研究的目的在于运用测功仪模拟赛艇2 000m比赛,以探究赛艇项目比赛过程中的供能特征.10名某省优秀赛艇运动员(男6女4)自愿参加赛艇测功仪6.5min的全力划.运用便携式气体代谢仪(CosMed,K4b2)所测得的摄氧量数据和血乳酸分析仪(Diagnostic C-line,EKF)所测得的血乳酸数据进行能量供应量的计算.结果表明,赛艇项目2 000m三大供能系统的比例分别为6.2％(无氧无乳酸)、10.1％(无氧乳酸)、83.7％(有氧).研究结果与前人研究相似,并进一步明确了有氧供能对于赛艇比赛的重要性.三大供能系统比例的确定为教练员安排训练负荷和评价运动员的运动能力提供了理论依据.     

人体运动协调形成过程中的肌电变化特征研究

本文通过研究原地掷标枪训练过程中人体肌电变化情况,旨在探讨人体运动协调形成过程中,肌肉用力的变化特征和规律。研究发现,运动训练可以改变某些肌肉在发力过程中的参与程度。初学者表现为躯干肌群i EMG和RMS值与优秀运动员差异显著,且训练前后差异无明显变化。     

女子赛艇优秀运动员运动素质与2 000 m测功仪成绩的动态关系

为揭示赛艇运动员各项运动素质与2 000 m测功仪成绩的关系.根据训练计划安排,定期、多次对优秀女子赛艇运动员的相关运动素质及专项2 000 m测功仪成绩进行系统测试.研究结果显示,在第1次测试时,全力2 000 m测功仪成绩与全力5 000 m(r=0.94)、全力500 m测功仪(r=0.74)和最大力量卧拉(r=-0.66)、最大力量深蹲(r=-0.56)、最大力量卧推(r=-0.54)成绩高度相关;全力2 000 m测功仪成绩与全力100 m测功仪成绩不呈显著性相关(r=0.46,P>0.05).在第2次测试时,全力2 000 m测功仪成绩与全力5 000 m(r=0.93)、全力500 m(r=0.87)、全力100 m测功仪(r=0.73)和最大力量卧拉(r=-0.68)成绩高度相关.全力2 000 m测功仪成绩与最大力量卧推(r=-0.48,P>0.05)、最大力量深蹲(r=-0.18,P>0.05)成绩不呈显著性相关.在第3次测试时,全力2 000 m测功仪成绩与全力500 m(r=0.92)、全力5 000 m测功仪(r=0.85)和最大力量卧拉(r=-0.62)、全力100 m测功仪(r=0.58)成绩高度相关;全力2 000 m测功仪成绩与最大力量卧推(r=-0.32,P>0.05)和最大力量深蹲(r=-0.38,P>0.05)成绩不呈显著性相关.研究结果说明优秀女子赛艇运动员各项运动素质与测功仪2 000m成绩之间是一个动态的关系,不是一成不变的.     

不同肌力训练时攀岩运动员腕伸屈肌的表面肌电频谱特征研究

本实验对8名参加第3届全国体育大会攀岩比赛的攀岩运动员进行不同负荷试验。记录腕伸屈肌的肌电变化和负荷持续时间。实验结果表明:平均功率频率(MPF)和中位频率(MF)的值均随持续时间的改变而呈先上升后下降的变化规律;MPF、MF的值变化与腕伸屈肌的负荷持续时间与多种因素有关。本研究认为,MF和MPF是可以反映腕伸屈肌的功能水平,可作为评价腕伸屈肌负荷水平的良好指标。     

等速运动负荷诱发肱二头肌疲劳过程中sEMG信号变化

本研究的目的在于观察动态等速运动诱发肱二头肌疲劳过程中 s EMG信号时频分析指标的动态变化规律 ,确定能够较好地运用于动态肌肉功能评价的 s EMG指标。研究结果表明 ,动态运动过程中时域分析指标 i EMG和 RMS的变化较小且与负荷持续时间无明显线性相关 ;频域分析指标 MPF和 MF变化较大 ,但是只有 MPF的变化与负荷持续时间呈明显线性相关 ;MPF时间序列曲线下降斜率与肌肉的总作功量之间明显相关 ,可作为评价肌肉动态负荷水平的生理学指标     

自行车运动员下肢肌肉sEMG特征及与输出功率的相关性

采用实验法,对运动员60 s全力蹬踏自行车下肢肌肉sEMG变化特征及与输出功率的相关性进行研究.结果显示:随着运动时间的延长和疲劳的加深,各肌肉表面肌电信号频域指标MF逐渐减小,MF与平均功率之间的相关性也达到显著性水平,提示其可作为评价自行车运动过程中运动员疲劳程度的指标.60 s全力蹬踏自行车运动后运动员股直肌和腓肠肌外侧肌肉MF值下降均特别明显,提示其在整个运动过程中的疲劳程度较深,可将其作为重点训练的肌群.     

国家队射箭运动员动作技术的肌电特性

运用美国产Noraxon表面肌电遥测系统对国家射箭队男、女各12名运动员进行测试,分析结果表明:国家射箭队运动员在射箭动作的不同阶段尚存在部分不合理的肌肉用力特点;相对来说,无论是举弓时的肌肉激活顺序、主要肌肉用力特点,还是动作的一致性,均是女子运动员较男子运动员合理;以肌电RMS幅值的"标准差与平均数的比值"这个派生指标对运动员进行多支箭肌肉用力的一致性评价较合理。     

Changes in force production, blood lactate and EMG activity in the 400-m sprint.

The neural activation (iEMG) and selected stride characteristics of six male sprinters were studied for 100-, 200-, 300- and 400-m experimental sprints, which were run according to the velocity in the 400 m. Blood lactate (BLa) was analysed and drop jumps were performed with EMG registration at rest and after each sprint. Running velocity (P less than 0.001) and stride length (P less than 0.05) decreased and contact time increased (P less than 0.01) during the 400-m sprint. The increase in contact time was greatest immediately after runs of 100 and 300 m. The peak BLa increased and the rate of BLa accumulation decreased with running distance (P less than 0.001). The height of rise of the centre of mass in the drop jumps was smaller immediately after the 300 m (P less than 0.05) and the 400 m (P less than 0.01) than at rest, and it correlated negatively with peak BLa (r = -0.77, P less than 0.001). The EMG and EMG:running velocity ratio increased with running distance. It was concluded that force generation of the leg muscles had already begun to decrease during the first quarter of the 400-m sprint. The deteriorating force production was compensated for until about 200-300 m. Thereafter, it was impossible to compensate for fatigue and the speed of running dropped. According to this study, fatigue in the 400-m sprint among trained athletes is mainly due to processes within skeletal muscle rather than the central nervous system.     

Upper limb muscle fatigue during prolonged Boccia games with underarm throwing technique

This study investigated the acute fatigue pattern in neuromuscular activity after a simulated Boccia game and the effect of fatigue pattern on sport performance. Nine elite Boccia athletes were tested before, during, and after a simulated game. Maximum ball speed was captured with video, and the target hitting rate and rating of perceived exertion (RPE) score were collected and analyzed. Electromyography signals from the upper trapezius, anterior deltoid, posterior deltoid, biceps brachii, triceps brachii, and wrist extensor muscles were collected by surface electrode and were evaluated with mean power frequency (MPF). Only the upper trapezius muscle showed fatigue as demonstrated by a reduction of MPF of 8% (p = 0.027) when comparing the first and last throws in a simulated game. Subjective RPE score increased during the game (118%, p = 0.004), and sports performance in terms of maximum ball speed (-12%, p = 0.004) and target hitting rate (-25%, p = 0.004) also deteriorated. In conclusion, fatigue on the upper trapezius muscle was demonstrated in elite Boccia athletes following a prolonged Boccia game and may have affected Boccia performance. Preventative measures against upper trapezius muscle fatigue and endurance training for synergists of the upper trapezius muscle may be considered in future studies.     

跳深时下肢肌肉的表面积分肌电值及其平均功率频率值的变化特征研究

同步使用Kistler三维测力平台、TM-6710CL高速摄像机和16道便携式无线遥测表面肌电测系统,对从不同下落高度跳深的12名田径跳跃运动员进行了测试,测试结果表明:受试者跳深着地阶段缓冲期的积分肌电值大于蹬伸期值;正常状态下跳深时,下肢所测大多数肌肉的表面积分肌电值均比相对疲劳状态下的值大;较低下落高度跳深时,所测肌肉表面肌电平均功率频率值大于较高下落高度时的值;正常状态跳深时,下肢所测肌肉表面肌电的平均功率频率值大于相对疲劳状态跳深时的值。     

湖北赛艇队备战十运会赛前2 000 m测功仪测试分析

根据湖北赛艇队备战"十运会"赛前3次2 000 m测功仪测试的成绩,利用百分比模型分别比较了公开级与轻量级,男子与女子运动员之间的差异,以及我省备战"十运会"队员与国内、国外优秀运动员的差异.结合运动员的水上成绩发现:利用功率/体重2/3得到的相对功率能更为准确反映赛艇运动员的实际专项能力.结果显示:我省男子项目较具竞争力.     

Muscle morphology of the vastus lateralis is strongly related to ergometer performance,sprint capacity and endurance capacity in Olympic rowers

Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates to rowing ergometer performance, sprint and endurance capacity of Olympic rowers. Eighteen rowers (12♂, 6♀, who competed at 2016 Olympics) performed an incremental rowing test to obtain maximal oxygen consumption, reflecting endurance capacity. Sprint capacity was assessed by Wingate cycling peak power. M. vastus lateralis morphology (volume, physiological cross-sectional area, fascicle length and pennation angle) was derived from 3-dimensional ultrasound imaging. Thirteen rowers (7♂, 6♀) completed a 2000-m rowing ergometer time trial. Muscle volume largely explained variance in 2000-m rowing performance (R² = 0.85), maximal oxygen consumption (R² = 0.65), and Wingate peak power (R² = 0.82). When normalized for differences in body size, maximal oxygen consumption and Wingate peak power were negatively related in males (r = ?0.94). Fascicle length, not physiological cross-sectional area, attributed to normalized peak power. In conclusion, vastus lateralis volume largely explains variance in rowing ergometer performance, sprint and endurance capacity. For a high normalized sprint capacity, athletes may benefit from long fascicles rather than a large physiological cross-sectional area.     

Prediction of 2000 m indoor rowing performance using a 30 s sprint and maximal oxygen uptake

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 - 3.6 years, height 1.68 - 0.54 m, body mass 67.1 - 11.7 kg; mean - s ) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake ( V O 2 ) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest V O 2 measured during the test was recorded as V O 2max (mean = 3.18 - 0.35 l· min -1 ). Peak power (380 - 63.2 W) and mean power (368 - 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 - 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), V O 2max (l· min -1 ), V O 2max (ml·kg -1 ·min -1 ), V O 2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent V O 2max ) and V E max (l·min -1 ) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time 2000 =- 0.163 (Power)14.213 ·( V O 2max l· min -1 ) + 0.738· (Fatigue) + 567.259 ( R 2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while V O 2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively.     

运动性肌肉疲劳的肌电图特征及其机制探讨

本文通过文献综述法简要总结了运动导致肌肉疲劳的表面肌电图特征,介绍了表面肌电图主要测量指标及其影响因素,同时对指标的特异性做了小结:MPF对于反映肌肉疲劳较MF更具敏感性;MPF在反映肌肉功能水平差异方面具有良好的特异性和敏感性;IEMG则是反映肌肉随时间而延长出现疲劳的1个良好指标。并对可能导致表面肌电图特征改变的机制作了探讨,最后对其应用在肌肉疲劳领域的前景进行了展望。     

Prediction of 2000 m indoor rowing performance using a 30 s sprint and maximal oxygen uptake

The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 +/- 3.6 years, height 1.68 +/- 0.54 m, body mass 67.1 +/- 11.7 kg; mean +/- s) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake (VO2) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest VO2 measured during the test was recorded as VO2max (mean = 3.18 +/- 0.35 l.min-1). Peak power (380 +/- 63.2 W) and mean power (368 +/- 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 +/- 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), VO2max (l.min-1), VO2max (ml.kg-1.min-1), VO2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent VO2max) and VEmax (l.min-1) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time2000 = -0.163 (Power) -14.213.(VO2max l.min-1) +0.738.(Fatigue) 7.259 (R2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while VO2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively.