赛艇运动员拉桨技术运动学特征及其相关肌肉sEMG分析

通过表面肌电和高速摄像同步测试方法,揭示我国优秀赛艇运动员拉桨技术环节肌肉用力特征及其相应的运动学变化.结果显示:1)赛艇运动员拉桨时间为0.8s,拉桨至与艇垂直时间占拉桨阶段的70％;2)拉桨环节肌肉活动顺序为股四头肌内侧头、股直肌、腓肠肌、背阔肌、肱二头肌、腹直肌;3)肌肉做功百分比大小顺序为肱二头肌＞股四头肌内侧头＞背阔肌＞股直肌＞腓肠肌＞腹直肌,aEMG值为背阔肌＞股四头肌内侧头＞腓肠肌＞肱二头肌＞股直肌＞腹直肌.提示:运动员拉桨前阶段占有很大的比重;背阔肌、股四头肌内侧头、肱二头肌在拉桨阶段起着重要的作用;运动员除躯干打开稍早外,技术动作比较规范稳定,肌肉用力协调.     

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

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.     

旋转推铅球最后用力阶段肌肉用力特征的sEMG分析

采用表面肌电对人体16块肌肉进行肌电测试,结合录像解析,分析高水平旋转推铅球运动员最后用力阶段表面积分肌电贡献率的大小,结果表明该阶段主要的用力肌肉为右腹外斜肌、左腿股直肌、右腿股直肌、左腿腓肠肌、右腿腓肠肌、三角肌和胸大肌。该阶段发力肌肉积分肌电贡献率的大小与该阶段的技术动作特点有密切关系。在平时训练时应注意发展主要发力肌肉的力量,同时也应该注意发展与此相关的其他肌肉的力量。     

柔道运动员投技中大外刈技术的表面肌电分析

以北京体育大学8名柔道运动员为研究对象,分为优秀组和普通组各4名,采用表面肌电测试方法并结合运动解剖学的基本理论对两组运动员柔道投技大外刈技术进行量化分析和评价,得出以下结论与建议:(1)sEMG信号分析中时域指标RMS和贡献率(work/loading)能较好反映柔道等复杂技术动作中肌肉的用力情况.(2)大外刈技术中两侧腹直肌、右侧腹外斜肌、肱二头肌、肱三头肌、臀大肌、股二头肌、腓肠肌内侧以及左侧三角肌后束、臀大肌、股直肌是主要用力肌肉,运动员在训练中应加强以上肌肉的练习.(3)普通组运动员左侧三角肌后束、左侧腹直肌、右侧肱二头肌力量过于薄弱,这可能是造成其技术不够成熟的因素之一,今后训练中应注意加强.(4)运动员在强化针对性肌肉力量练习的同时,除选择一般力量训练方法外,应多尝试采用适合柔道大外刈技术的专项力量训练方法,如拉滑车、爬绳、立卧撑等.     

基于表面肌电技术对女子拳击运动员不同出拳技术分析

以内蒙古女子拳击运动员为研究对象,利用遥测表面肌电仪记录运动员各种出拳技术过程中相关肌肉的电活动,建立运动员不同出拳技术时肌电特征模型,结果发现:在拳击的各种出拳技术动作中,主动肌的积分肌电百分比要显著高于拮抗肌,拮抗肌能够积极参与到出拳技术动作中;在后手直拳技术动作中,肱三头肌和三角肌前束的电活动最活跃,分别为15.7％和18.0％;在勾拳技术动作中,肱二头肌、三角肌前束、背阔肌电活动较强,分别为15％、14％和17.4％;在后手摆拳技术动作中,三角肌外侧束的做功百分比最高为16.7％,其次为肱二头肌13.6％、腹直肌13.7％、背阔肌14.3％.鉴于不同出拳技术动作的不同,各块肌肉工作表现出不同的工作特征.     

我国高水平女子铁饼运动员掷铁饼肌肉用力特征的分析

运用摄像和肌电图同步测试手段,对我国现役4名高水平女子铁饼运动员完整投掷过程中,参与动作主要的8块肌肉的表面肌电图(sEMG)进行测试和分析.结果表明,她们所测试的肌肉表现出不同的sEMG活动变化特征,孙太凤、宋爱民的肌肉活动具有一定的变化节奏,李艳凤和潘赛丽则表现出部分肌肉持续用力的时间较长.肌肉表现出活动与主动用力程度大小顺序为:右腿股二头肌、左腿股内侧肌、右腿股内侧肌、左腿股二头肌、左侧竖脊肌、右侧竖脊肌、右侧腹外斜肌和左侧腹外斜肌.股二头肌与股内侧肌主要的用力肌肉群,主要在最后用力阶段.腹外斜肌的活动程度最小.     

优秀女子拳击运动员后手直拳技术动作上肢肌肉表面肌电分析

目的:探讨拳击运动员后手直拳动作内部神经肌肉系统协同变化,提高我国女子拳击运动员的训练水平.方法:使用表面肌电技术对沈阳体育学院8名健将级女子拳击运动员后手直拳动作进行分析.结果:在后手直拳击打过程中上肢肌肉中三角肌前束做功百分比最高,平均为35%;后手直拳击打过程中主动肌的激活顺序为三角肌前束、肱三头肌和尺侧腕屈肌,肌肉由近端到远端依次激活.结论:后手直拳击打动作中上肢拮抗肌发挥着重要作用;从肌肉激活顺序来说后手直拳击打动作符合鞭打技术动作原理,在平时训练中加强上肢拮抗肌的训练.     

我国优秀双人滑男运动员落冰及模仿训练肌电特征研究

目的：探讨花样滑冰跳跃动作落冰过程中肌肉的工作特征及相关陆地模仿的训练效果。方法：以我国优秀双人滑男运动员张某为研究对象,利用 Mega ME6000肌电测试仪对其完成后外点冰两周跳、陆地两周跳、凳上跃起动作落地过程支撑腿落地后0.8 s内双侧胫骨前肌、腓肠肌外侧头、股直肌、股二头肌、臀大肌、竖脊肌、腹外斜肌和腹直肌的表面肌电信号进行采集,通过MegaWin2.4对原始数据进行处理分析。结果：完成专项动作时积分面积较大的8块肌肉依次为右侧股二头肌、右侧股直肌、右侧腓肠肌外侧头、左侧股二头肌、右侧胫骨前肌、右侧臀大肌、左侧臀大肌和右侧竖脊肌,多数工作肌的积分肌电峰值出现在落冰后的0.4 s左右;完成专项动作各肌肉积分面积与凳上跃起动作具有较高相关性（r=0.578,P=0.019）,与 陆地两周跳动作不相关;肌肉贡献度较大的肌肉中,专项动作与两种陆地模仿动作相比,支撑腿股二头肌、股直肌和腓肠肌外侧头的平均积分肌电 值明显偏高,积分肌电峰值出现时间不同。结论：完成后外点冰两周跳落冰动作的主要工作肌为支撑腿各肌群、同侧竖脊肌及摆动腿的股二头肌、臀大肌;凳上跃起和陆地两周跳两种陆地模仿练习的肌肉工作特征与专项动作有一定差异,可作为辅助训练手段,但不宜过多采用。     

陈式太极拳掩手肱捶动作技术的比较分析

目的：对陈式太极拳的典型发劲动作掩手肱捶进行测试,采集不同水平练习者掩手肱捶劲力发放的运动学、动力学和肌电结果,分析和讨论掩手肱捶劲力发放的特点和训练方法。方法：研究对象共14人,试验组和对照组各7人。试验仪器包括VICON三维运动分析系统,Noraxon16导遥测肌电DTS系统,中国功夫测试工程人。测试动作为陈式太极拳的典型发劲动作掩手肱捶。试验组和对照组的测试结果比较采用配对样本T检验,试验组空击动作与实击动作的结果比较采用独立样本T检验。结果：陈式太极拳试验组在右手位移、右手速度、加速度、最大加速度的结果上高于对照组,虽然试验组的平均肌电明显小于对照组,但试验组的肱桡肌、肱二头肌、肱三头肌、三角肌、背阔肌、竖脊肌峰值肌电值大于对照组,其中肱二头肌和背阔肌的差异有统计学意义;在击打效果上,试验组击打在工程人心脏、左肺、右肺和胃的加速度值明显高于对照组。结论：试验组的峰值肌电高于对照组,主要是肱桡肌、肱二头肌、肱三头肌、三角肌、背阔肌、竖脊肌在完成掩手肱捶时用力明显,建议在完成该动作时应进行针对性地练习;掩手肱捶击打到工程人时的加速度呈双峰波型,第1个波形高,而第2个波形低,这与该动作在动作结束时有旋腕动作有关。     

羽毛球后场起跳正手杀球的表面肌电研究

目的为分析羽毛球杀球动作的肌肉用力特征。方法运用表面肌电的测试方法,以二级6名优秀羽毛球运动员为测试对象,以起跳杀球动作为依据,研究选取上肢和躯干两组肌肉。结果三角肌、斜方肌、肱二头肌、背阔肌放电较早且持续时间最长;在起跳引拍阶段三角肌、肱二头肌、斜方肌放电最大,为获得杀球高度表现出积极动员;肱三头肌、三角肌、桡侧腕屈肌、肱桡肌放电大且肌肉利用率和贡献率较高,为完成杀球关键动作至关重要。结论训练中应加强这几块肌肉的力量耐力和速度力量训练,而且根据运动员的个体差异,区别对待地进行合理、科学的训练。     

三种深蹲动作模式肌电特征的研究

目的：对3种不同深蹲模式进行肌电测试,以期探讨不同模式下动作的合理性,为教学、训练提供一定的理论依据。方法：本文运用文献资料法、实验法和数理统计法对不同模式的肌电测试进行对比分析研究。结果：动作模式1与动作模式2相比,股内侧肌、股直肌、股外侧肌、臀大肌有非常显著性差异（P〈0.01）,股二头肌有显著性差异（P〈0.05）。动作模式1与动作模式3相比,股内侧肌、股直肌、股外侧肌、臀大肌有非常显著性差异（P〈0.01）,股二头肌有显著性差异（P〈0.05）。动作模式2与动作模式3相比,股内侧肌、臀大肌有非常显著性差异（P〈0.01）,股直肌、股外侧肌有显著性差异（P〈0.05）,股二头肌没有显著性差异（P〉0.05）。结论：3种不同模式深蹲动作的股外侧肌、股直肌、股内侧肌、股二头肌、臀大肌的积分肌电数值表现出显著性差异,动作模式3优于其它两种动作模式。在深蹲训练中强调臀部肌肉的主动收缩,才能更好的提高下肢力量的作用。     

Electromyographic analysis of lower limb muscles during the golf swing performed with three different clubs

The aim of this study was to describe and compare the EMG patterns of select lower limb muscles throughout the golf swing, performed with three different clubs, in non-elite middle-aged players. Fourteen golfers performed eight swings each using, in random order, a pitching wedge, 7-iron and 4-iron. Surface electromyography (EMG) was recorded bilaterally from lower limb muscles: tibialis anterior, peroneus longus, gastrocnemius medialis, gastrocnemius lateralis, biceps femoris, semitendinosus, gluteus maximus, vastus medialis, rectus femoris and vastus lateralis. Three-dimensional high-speed video analysis was used to determine the golf swing phases. Results showed that, in average handicap golfers, the highest muscle activation levels occurred during the Forward Swing Phase, with the right semitendinosus and the right biceps femoris muscles producing the highest mean activation levels relative to maximal electromyography (70–76% and 68–73% EMG_MAX, respectively). Significant differences between the pitching wedge and the 4-iron club were found in the activation level of the left semitendinosus, right tibialis anterior, right peroneus longus, right vastus medialis, right rectus femuris and right gastrocnemius muscles. The lower limb muscles showed, in most cases and phases, higher mean values of activation on electromyography when golfers performed shots with a 4-iron club.     

Lower limb muscle activity during table tennis strokes

This study aimed to compare the muscle activity of lower limbs across typical table tennis strokes. Fourteen high-level players participated in this study in which five typical strokes (backhand top, forehand top, forehand spin, forehand smash, flick) were analysed. Surface electromyography activity (EMG) of eight muscles was recorded (gluteus maximus, biceps femoris, vastus medialis, vastus lateralis, rectus femoris, gastrocnemius medialis, gastrocnemius lateralis, soleus) and normalised to the maximal activity measured during squat jump or isometric maximal voluntary contractions. The forehand spin, the forehand top and the forehand smash exhibited significant higher EMG amplitude when compared with other strokes. Both biceps femoris and gluteus maximus were strongly activated during the smash, forehand spin and forehand top (from 62.8 to 91.7% of maximal EMG activity). Both vastii and rectus femoris were moderately to strongly activated during the forehand spin (from 50.4 to 62.2% of maximal EMG activity) whereas gastrocnemii and soleus exhibited the highest level of activity during the smash (from 67.1 to 92.1% of maximal EMG activity). Our study demonstrates that offensive strokes, such as smash or forehand top, exhibit higher levels of activity than other strokes.     

Quadriceps EMG muscle activation during accurate soccer instep kicking

Six competitive soccer players were recruited to examine EMG activation in three quadriceps muscles during a kicking accuracy task. Participants performed three maximum instep place kicks of a stationary ball, 11 m perpendicular from the centre of the goal line towards targets (0.75 m(2)) in the four corners of the goal. Surface EMG of the vastus lateralis, vastus medialis, and rectus femoris of the kicking leg was normalized and averaged across all participants to compare between muscles, targets, and the phase of the kick. Although no significant difference were observed between muscles or kick phases, kicks to the right targets produced significantly greater muscle activity than those towards the left targets (P < 0.01). In addition, kicks towards the top right target demonstrated significantly greater muscle activity than towards the top and bottom left (P < 0.01). Under accurate soccer shooting conditions, kicks aimed to the top right corner of the goal demonstrated a higher level of quadriceps muscle activation than those towards the other corners.     

Muscle - tendon unit mechanical and morphological properties and sprint performance

The objective of this study was to determine whether sprint performance is related to the mechanical (elongation - force relationship of the tendon and aponeurosis, muscle strength) and morphological (fascicle length, pennation angle, muscle thickness) properties of the quadriceps femoris and triceps surae muscle - tendon units. Two groups of sprinters (slow, n = 11; fast, n = 17) performed maximal isometric knee extension and plantar flexion contractions on a dynamometer at 11 different muscle - tendon unit lengths. Elongation of the tendon and aponeurosis of the gastrocnemius medialis and the vastus lateralis was measured using ultrasonography. We observed no significant differences in maximal joint moments at the ankle and knee joints or morphological properties of the gastrocnemius medialis and vastus lateralis between groups (P > 0.05). The fast group exhibited greater elongation of the vastus lateralis tendon and aponeurosis at a given tendon force, and greater maximal elongation of the vastus lateralis tendon and aponeurosis during maximum voluntary contraction (P < 0.05). Furthermore, maximal elongation of the vastus lateralis tendon and aponeurosis showed a significant correlation with 100-m sprint times (r = -0.567, P = 0.003). For the elongation - force relationship at the gastrocnemius medialis tendon and aponeurosis, the two groups recorded similar values. It is suggested that the greater elongation of the vastus lateralis tendon and aponeurosis of the fast group benefits energy storage and return as well as the shortening velocity of the muscle - tendon unit.     

The Reliability of Aerobic Capacity (VO2max ) Testing in Adolescent Girls

Purpose: This study compared the relative peak torque and normalized electromyographic (EMG) mean frequency (MNF) responses during fatiguing isokinetic muscle actions for men versus women. Method: Twenty men (M _age ± SD = 22 ± 2 years) and 20 women (M _age ± SD = 22 ± 1 years) performed 50 maximal concentric isokinetic muscle actions of the leg extensors at a velocity of 180°/s while surface EMG signals were detected from the vastus lateralis, rectus femoris, and vastus medialis. The dependent variables were initial, final, and average peak torque; percent decline; the estimated percentage of fast-twitch fibers for the vastus lateralis; and the linear slope coefficients and y-intercepts for normalized EMG MNF versus repetition number. The data were analyzed with independent-samples t tests and 2-way mixed-factorial analyses of variance. Results: The mean initial, final, and average peak torque values for men were greater than those for women. There were no mean differences for percent decline and the estimated percentage of fast-twitch fibers for the vastus lateralis. There were also no sex differences for the linear slope coefficients, but there were differences among the muscles (vastus medialis>vastus lateralis>rectus femoris). The mean y-intercept for the vastus lateralis for men was greater than that for women. Conclusions: Men demonstrated greater peak torque values than those for women, but the declines in peak torque and normalized EMG MNF were similar between the sexes. The vastus medialis was more fatigue-resistant than both the vastus lateralis and rectus femoris.     

我国高水平女子铁饼运动员专项力量练习肌肉活动特征的分析

目的通过实验研究专项练习对肌肉力量训练的作用,为运动训练中有针对性地、合理地选择专项力量练习动作,提高专项力量训练效果提供参考。方法运用摄像和肌电图同步测试手段,对我国现役3名高水平女子铁饼运动员4个专项力量练习,参与动作的8块主要肌肉的表面肌电(sEMG)进行测试和分析。结果 4个专项练习总体上是以发展下肢的股内侧肌和股二头肌力量为主,但侧重点不完全相同。15 kg挥片转体练习对竖脊肌的作用效果较明显,30 kg杠铃抡摆练习动作对发展腹外斜肌一次性用力力量最有效。结论 5 kg壶铃轮摆转体是对肌肉作用程度及强度最强的一种练习,也是发展股二头肌力量最有效的练习。原地挥片(1.5 kg)练习对肌肉的作用程度有限。     

The acute effects of bodyweight suspension exercise on muscle activation and muscular fatigue

This investigation examined effects of two exercise modes (barbell, BB; bodyweight suspension, BWS) on muscle activation, resistance load, and fatigue. During session one, nine resistance-trained males completed an elbow flexion one-repetition maximum (1RM). During sessions two and three, subjects completed standing biceps curls to fatigue at 70% 1RM utilizing a randomized exercise mode. Surface electromyography (sEMG) recorded muscle activation of the biceps brachii, triceps brachii, anterior deltoid, posterior deltoid, rectus abdominis, and erector spinae. BWS resistance load was measured using a force transducer. Standing maximal voluntary isometric contractions of the elbow flexors recorded at 90° were used to determine the isometric force decrement and rate of fatigue (ROF) during exercise. sEMG and resistance load data were divided into 25% contraction duration bins throughout the concentric phase. BWS resulted in a 67.7?±?7.4% decline in resistance load throughout the concentric phase (p?≤?0.05). As a result, BB elicited higher mean resistance loads (31.4?±?4.0?kg) and biceps brachii sEMG (84.7?±?27.8% maximal voluntary isometric contractions, MVIC) compared with BWS (20.4?±?3.4?kg, 63.4?±?21.6% MVIC). No difference in rectus abdominis or erector spinae sEMG was detected between exercise modes. Isometric force decrement was greater during BWS (?21.7?±?7.0?kg) compared with BB (?14.9?±?4.7?kg); however, BB (?3.0?±?0.8?kg/set) resulted in a steeper decline in ROF compared with BWS (?1.7?±?0.6?kg/set). The variable resistance loading and greater isometric force decrement observed suggest that select BWS exercises may resemble variable resistance exercise more than previously considered.     

Effect of cadence on volume and myoelectric activity during agonist-antagonist paired sets (supersets) in the lower body

The aim of this study was to investigate the effect of cadence on volume load (VLoad) and muscle activity during agonist –antagonist paired sets (APS) in the lower body. Twelve trained men (24.0 ± 3.3 years; 78.3 ± 9.7 kg; 1.77 ± 0.58 m) volunteered to participate in this study. After the 10 maximum repetition test for leg extension and seated leg curl, participants performed three experimental protocols: first protocol (traditional)—three sets of only leg extension (60 bpm); second protocol (fast cadence)—three sets of leg extension, with each set preceded by one set on the seated leg curl with fast cadence (90 bpm); third protocol (slow cadence)—similar to the second, but seated leg curl with slow cadence (40 bpm). The total number of repetitions, VLoad and the electromyography activity for the vastus lateralis, vastus medialis and rectus femoris muscles were recorded. The VLoad was higher during APS than the traditional method, but the cadence (fast or slow) of antagonist exercise did not influence VLoad. Muscle activity of vastus lateralis was higher during traditional protocol; on the other hand, rectus femoris showed higher activity on APS fast cadence protocol, indicating that APS has a different influence on quadriceps components.