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1.
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
2.
主动肌和拮抗肌功能转变瞬间的肌电平均功率频率变化 总被引：2，自引：1，他引：1
目的:通过对主动肌和拮抗肌功能转变瞬间肌电平均功率频率的观察,探讨中枢控制因素在决定MPF变化中的独立性作用.方法:10名健康男性志愿者在完成60%MVC强度的疲劳性等长屈肘运动负荷试验后,瞬间转变肌肉工作性质,完成60%MVC强度的疲劳性等长伸肘运动,分别记录肱二头肌和肱三头肌的sEMG信号,观察两次疲劳试验以及瞬间转变过程中肌电MPF等sENG指标变化.结果:等长屈肘和等长伸肘快速转变的瞬间,主动肌和拮抗肌MPF等各项sEMG信号分析指标均发生了显著性改变,表现出明显的跃变现象;无论是转变之前,还是转变之后的等长疲劳试验过程中,主动肌与拮抗肌的MPF、C(n)和%DEF均表现出类似的变化规律,而拮抗肌AEMG则维持相对恒定.结论:中枢运动控制是导致疲劳过程中MPF单调递减变化的独立性作用因素,其可能的作用机制是CNS将主动肌与拮抗肌作为一组控制肌群实施同步控制. 相似文献
3.
目的:躯干突发失衡是造成腰椎稳定性破坏,引发急性腰肌损伤和腰痛的重要原因。采用躯干突发失衡的研究范式,研究失衡心理预期对躯干突发减载性失衡诱发腰椎稳定肌快速反应延时和强度的影响,探讨主观心理预期减少突发减载性失衡状况下腰部肌肉损伤的生理机制。方法:11名健康男性青年受试者,分别在有、无失衡预期的条件下实施左右侧躯干肌肉突发减载性失衡试验,同步检测双侧腰部多裂肌、腰部竖脊肌和腹外斜肌的sEMG信号,计算上述被检肌肉的快速反应强度和反应时间,考察躯干突发减载性失衡对被检肌肉快速反应强度和反应时间的影响以及失衡心理预期的生理效应。结果:与安静状态相比,躯干突发减载性失衡条件下腰部多裂肌、腰部竖脊肌和腹外斜肌AEMG均显著升高,其中同侧和对侧腰部多裂肌和腰部竖脊肌AEMG之间没有明显差异,但同侧腹外斜肌的反应强度明显大于对侧;失衡心理预期对同侧腰部多裂肌、腰部竖脊肌和腹外斜肌的AEMG反应具有一定程度的弱化作用趋势,对对侧腰部多裂肌和腹外斜肌的AEMG反应具有明显弱化作用;失衡心理预期能够加快同侧和对侧腰部多裂肌、腰部竖脊肌和腹外斜肌的快速反应延时,其中对侧腰部多裂肌的快速反应延时的作用具有显著统计学意义。结论:躯干突发减载性失衡能够明显激活腰部整体和局部稳定肌的活动,单侧失衡心理预期能够明显加快对侧腰椎多裂肌快速反应延时,弱化腰椎稳定肌的反应强度,在不过度增加腰椎载荷的条件下增强腰椎稳定性,其作用机制与主观心理预期引起的中枢神经系统前馈控制作用有关。 相似文献
4.
目的:研究动态瑞士球练习对游泳运动员躯干核心区4个主要肌群的刺激强度,旨在为游泳运动员的瑞士球练习提供一定的参考依据。方法:选择10名男子一级游泳运动员为受试对象。利用BIOPAC-MP150多导生理仪,对受试者在24种动态瑞士球练习中的腹直肌、腹外斜肌、竖脊肌和多裂肌这4个肌群进行表面肌电测试,计算各受试肌群的AEMG值。通过聚类将24种瑞士球练习分为4类,在平面直角坐标图上绘制各类瑞士球练习中各肌群的AEMG值图形并计算图形面积。结果:第1类是以腹外斜肌和竖脊肌为主导发力的练习;第2类是以竖脊肌主导发力的练习;第3类是以腹直肌和腹外斜肌为主导发力的练习;第4类是以竖脊肌和多裂肌为主导发力的练习。结论:24种瑞士球练习对躯干核心区4个肌群的AEMG值分别都在10%～50%左右,均属于中、低负荷强度的练习;运用坐标图面积计算法可以计算出瑞士球动作对躯干肌群的总刺激强度,能够简单并直观地表现出各动作对躯干肌群的刺激情况;与水中技术动作联系的紧密性以及无固定支撑是瑞士球练习应用于游泳运动的核心特征,运动员与教练员可以遵从训练原则,通过多种手段将瑞士球练习合理应用于游泳专项训练中。 相似文献
5.
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。 相似文献
6.
张立 《武汉体育学院学报》1988,(1)
在科学选材中,肌纤维类型的测定已成为一个重要课题。采用肌电方法间接测定肌纤维类型,国内外学者做了大量工作。不同肌纤维类型代谢,收缩特征导致肌电参数各有差异。实验证明,快肌百分比较高的肌肉进行持续性收缩时积分肌电图(IEMG)增加,平均功率频率向低频转移。而慢肌百分比较高的肌肉积分肌电图振幅小于快肌振幅,功率谱变化小而稳定。机制主要是由于快肌运动单位较易疲劳,为维持力量输出,大量慢肌运动单位募集造成低频成分增加。此外快肌强大的收缩力量使肌内压增高,肌肉内供血不足和乳酸堆积是功率谱变化的另一个原因。这些机制已成为采用肌电方法测定肌纤维类型的主要依据。 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.
目的:本文旨在探讨不同动态腹直肌训练动作对腹直肌下部锻炼效果的影响,为腹直肌训练提供参考。方法:让受试者做屈腿卷腹、直腿卷腹、屈腿仰卧起坐、直腿仰卧起坐、仰卧两头起、健腹轮、下斜板仰卧起坐7种常用的徒手腹直肌锻炼动作,同时应用ME6000-16表面肌电仪对左侧腹直肌测出做每种腹直肌锻炼动作时的表面肌电信号,并对其信号的时域指标平均振幅AEMG进行对比分析。结果:屈腿卷腹动作AEMG标准化值最低为0.327±0.160;仰卧两头起AEMG标准化值最高为0.805±0.190。卷腹、屈腿仰卧起坐、俯身滚动健腹轮之间的AEMG标准化值也较低,且相互之间差异不显著。但与腹直肌AEMG标准化值较高的下斜板仰卧起坐、直腿仰卧起坐、仰卧两头起动作差异显著。结论:仰卧两头起,下斜板仰卧起坐,直腿仰卧起坐动作对腹直肌刺激程度较高。仰卧两头起的刺激程度最高,俯身滚动健腹轮对腹直肌刺激程度较低。 相似文献
9.
研究目的:选取国家队优秀男子跆拳道运动员的后横踢技术动作进行肌电分析,揭示跆拳道运动员的用力特征。研究方法:运用美国产Noraxon表面肌电遥测系统对14名国家跆拳道队男子运动员进行测试,并根据后横踢技术特点,分别选取了三组肌肉进行测试。研究结果:1)从肌肉的激活顺序来看,以左侧竖脊肌、左侧胫骨前肌最先发力,但与此同时,右侧的胫骨前肌和腓肠肌也同时被激活;2)从肌力特征来看,右侧肌群的肌力值相对较大,在整个的后横踢技术动作中占有绝对的优势,相比之下,左侧肌群肌力较小,并且肌肉的募集能力相对较低(40%以下);3)在肌电的持续时间上,左侧肌群持续时间相对较短(0.20s以下),右侧肌群持续时间较长,表明它们是主要做功肌群,但左侧半腱半膜肌无论是在肌力动员方面(46.8%),还是在积分肌电方面(326.00uv.s),或是在激活顺序(0.06s)和持续时间上(0.70s),都表现出非常高地贡献作用。研究结论:由于左侧和右侧具有同时肌肉放电的现象,因此,训练中在加强左侧支撑用力的同时,应逐步提高运动员动作腿的起动速度训练,并加强右侧主动肌和拮抗肌的用力效果。此外,应特别关注左侧半腱半膜肌等肌肉的力量训练。 相似文献
10.
运用美国产Noraxon表面肌电遥测系统对国家射击队男子手枪慢射运动员、河北省队运动员和业余运动员进行测试.结果表明:用贡献率和振幅变化率评价男子手枪慢射运动员持枪臂主要肌群用力的稳定性是可行的,其中振幅变化率指标更敏感和有效;运动员持枪臂肌肉稳定性越高,成绩越好. 相似文献
11.
聚焦跑步时髌股关节生物力学特征,探究穿着不同极简指数(MI)跑鞋对髌股关节接触力、应力等的即刻影响。选取15名习惯后跟着地的健康男性跑者,分别穿着两种MI跑鞋(MI 86%极简跑鞋和MI 26%缓冲跑鞋),使用Vicon红外运动捕捉系统、Kistler三维测力台同步采集3.33 m/s(速度变化范围±5%)跑速下的膝、踝关节运动学和地面反作用力,通过逆向动力学等计算股四头肌肌力、髌股关节接触力、髌股关节接触面积以及髌股关节接触应力。结果显示:两种跑鞋条件下的冲击力峰值和蹬地力峰值均无明显差异。与缓冲跑鞋相比,穿着极简跑鞋跑步时,膝关节最大屈曲角度显著降低(P<0.01);髌股关节接触面积显著减小(P<0.01);膝关节伸肌峰值力矩显著下降(P<0.01);髌股关节接触力和应力峰值均显著减小(P<0.05)。研究表明,相比缓冲跑鞋,穿着极简跑鞋在未影响触地后冲击力峰值的同时,通过降低伸膝力矩大幅度减少髌股关节接触力(下降17.02%)、降低髌股关节接触应力,从而有效改善支撑期髌股关节负荷,为进一步减小髌股关节疼痛综合征风险提供可能。 相似文献
12.
通过对3种篮球鞋足跟部压缩性能的进行比较研究,从而对不同篮球鞋鞋底缓冲减震功能进行科学评价.对1名篮球专业的大学生穿着3种国内外拥有顶尖技术的高端品牌篮球鞋(NIKE FLIGHT96、ADIDAS TS PROMODEL和ANTA"霸道"三代)在正常步行速度下的足底压力分布的测试,结合Instron材料力学试验机对3种不同类型的鞋底材料进行压缩试验,对相关数据进行分析.通过3双鞋压缩行为、能量吸收的特征和应力松弛的参数来比较和分析,在相同应力下,NIKE的应变最小,NIKE的模量和能量吸收最大,其次为ANTA和ADIDAS;在应力松弛的试验中,NIKE的应力松弛衰减度为最小,ANTA和ADIDAS几乎相同. 相似文献
13.
为了给广大体育爱好者从琳琅满目的运动鞋中选择适合自己的慢跑鞋提出建议,从肌电学和气体代谢方面分析穿4种不同慢跑鞋的能耗。肌电实验结果表明,穿不同慢跑鞋走(1.5 m/s)、跑(3.5 m/s)时,由于跑鞋的重量差异以及结构差异导致下肢8块肌肉放电量出现比较明显差异;气体代谢结果表明,穿不同类型的慢跑鞋在跑台上进行15分钟3.5 m/s匀速跑时,能量消耗差异也比较大。结合跑鞋和自身情况,运动爱好者要有目的性地选择适合自己的运动鞋。 相似文献
14.
Despite the growing interest in minimalist shoes, no studies have compared the efficacy of different types of minimalist shoe models in reproducing barefoot running patterns and in eliciting biomechanical changes that make them differ from standard cushioned running shoes. The aim of this study was to investigate the acute effects of different footwear models, marketed as “minimalist” by their manufacturer, on running biomechanics. Six running shoes marketed as barefoot/minimalist models, a standard cushioned shoe and the barefoot condition were tested. Foot–/shoe–ground pressure and three-dimensional lower limb kinematics were measured in experienced rearfoot strike runners while they were running at 3.33 m · s?1 on an instrumented treadmill. Physical and mechanical characteristics of shoes (mass, heel and forefoot sole thickness, shock absorption and flexibility) were measured with laboratory tests. There were significant changes in foot strike pattern (described by the strike index and foot contact angle) and spatio-temporal stride characteristics, whereas only some among the other selected kinematic parameters (i.e. knee angles and hip vertical displacement) changed accordingly. Different types of minimalist footwear models induced different changes. It appears that minimalist footwear with lower heel heights and minimal shock absorption is more effective in replicating barefoot running. 相似文献
15.
James Frank Wilson 《Sports Engineering》2011,14(2-4):111-117
For a shod heel-striking runner, classical mechanics was used to predict the stresses and displacements for the shoe’s heel, with and without reinforcement. The shoe’s heel loading was based on a typical runner’s measured plantar pressure distribution fitted to a hemispheric pressure dome. Experiments showed that the shoe’s heel region was approximately linearly elastic, so that classical solutions were appropriate for an elastic half-space heel model. Here, the surface dome heel pressure within the heel area and image point loads beyond the heel boundary were superimposed to predict realistic heel boundary stresses and displacements. Results for two limiting boundary conditions were investigated: a vanishing radial boundary stress with maximum lateral heel bulging, and complete suppression of lateral bulging using radial heel reinforcement. The theoretical results herein can serve as guidelines for the development of a new class of running shoes with optimal heel reinforcement between these two boundary limits. This optimisation would lead to more comfortable and efficient running. 相似文献
16.
高跟鞋-步态-损伤之生物力学研究 总被引：1，自引：0，他引：1
高跟鞋状态下的“足一鞋”生物力学研究已引起学界和业界的高度重视。文章在综合国内外研究文献的基础上，系统总结了高跟鞋状态下的步态特征及运动损伤之生物力学机理，并对高跟鞋及由此引发的运动损伤等研究热点进行了探讨。高跟鞋状态的步态特征表现为鞋跟高度增加会使足底压力发生重新分配即足前掌压力增大、足后掌压力减小。高跟鞋运动损伤的研究表明穿着高跟鞋不仅能引发足部疾病，还可引发腰背疼痛、应力性骨折、骨关节炎等疾病。预计对不同跟高进行的高敏度研究及高跟鞋对上肢乃至全身骨骼肌肉系统影响的生物力学研究都将成为高跟鞋状态的未来研究趋势。 相似文献
17.
Vertical (FN) and horizontal (FH) forces were recorded while four vertically-loaded court shoes were dragged horizontally across six types of floor surface. Variation in coefficient of limiting friction (FH/FN) between floor surfaces was greater than that between shoes. Squash strokes were also performed on the same surfaces during which FH/FN was calculated. Slips occurred on some surfaces either at heel contact or upon attainment of full-sole contact. It is concluded that the coefficient of limiting friction obtained during full-sole contact with the floor is a suitable means of distinguishing between tractional qualities of shoes. Alternatively, this measure is an inadequate predictor of the likelihood of slips in the game of squash racquets. Dusty floor conditions produce poor traction as does a damp sealed floor. As sweat droplets are unavoidable in the game, floors sealed with urethane represent a significant hazard. Bare, clean, wooden flooring which can absorb moisture represents a better surface than a sealed floor from the point of view of traction. 相似文献
18.
The purpose of this study was to determine whether there are differences in the perceived comfort, plantar pressure, and rearfoot motion between laced running shoes and elastic-covered running shoes. Fifteen male amateur runners participated in the study. Each participant was assigned laced running shoes and elastic-covered running shoes for use during the study. The perceived comfort, plantar loading, and rearfoot motion control of each type of shoes during running were recorded. When the laced running shoes and elastic-covered running shoes were compared, the elastic-covered running shoes were given a lower perceived comfort rating in terms of shoe length, width, heel cup fitting, and forefoot cushioning. The elastic-covered running shoes also recorded higher peak plantar pressure in the lateral side of the forefoot, as well as larger maximum rearfoot pronation. Overall, shoelaces can help runners obtain better foot-shoe fit. They increase the perceived comfort, and decrease the maximum pronation and plantar pressure. Moreover, shoelaces may help prevent injury in running by allowing better control of the aforementioned factors. 相似文献
19.
Alexis Herbaut Emilie Simoneau-Buessinger Franck Barbier Christophe Gillet Maxime Roux Nils Guéguen 《European Journal of Sport Science》2017,17(10):1261-1269
Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8?mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (?73%, p?=?.005) but increased peak ankle plantarflexors moment (+47%, p?=?.050) and peak ankle power absorption (+107%, p?=?.005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces. 相似文献
20.
Wing-Kai Lam Chris Chi-Wai Cheung Aaron Kam-Lun Leung 《Journal of sports sciences》2020,38(20):2374-2381
ABSTRACT This study examined the effects of shoe collar-height and counter-stiffness on ground reaction force (GRF), ankle and knee mechanics in landing. Eighteen university basketball players performed drop landing when wearing shoes in different collar height (high vs. low) and counter-stiffness (stiffer vs. less stiff). Biomechanical variables were measured with force platform and motion capturing systems. Two-way repeated measures ANOVA was performed with α = 0.05. Wearing high collar shoes exhibited smaller peak ankle dorsiflexion and total sagittal RoM, peak knee extension moment, but larger peak knee varus moment than the low collar shoes. Stiffer counter-stiffness shoes related to smaller ankle inversion at touchdown and total coronal RoM, but larger peak knee flexion and increased total ankle and knee sagittal RoM than the less stiff counter-stiffness. Furthermore, wearing stiffer counter-stiffness shoes increased forefoot GRF peak at high collar condition, while no significant differences between counter-stiffness at low collar condition. These results suggest that although higher collar height and/or stiffness heel counter used can reduce ankle motion in coronal plane, it would increase the motion and loading at knee joint, which is susceptible to knee injuries. These findings could be insightful for training and footwear development in basketball. 相似文献