下肢肌肉功能模型应用软件的开发与应用

目的建立人体下肢肌肉功能的数学模型并编写相应的计算机软件,为人体运动过程中的下肢各肌肉力学描述及评估提供快速可靠的数据支持。方法利用现有的国人下肢肌肉附着点的三维坐标数据及其与体表骨性形态学参数的回归方程等相关研究成果,利用VisualC++6.0平台,编写下肢肌肉功能评定软件。结果软件系统可输出任意模拟姿态或实际运动过程中的下肢肌肉功能参数。结论本研究成果可从肌肉动力学层面来指导运动员的专项力量训练,提高运动成绩,也可应用于相关医学领域。     

尸体腰椎研究中的肌肉模拟

如果我们在体外脊柱运动研究中没有对肌肉作用进行适当的模拟则研究结果无多大的临床意义。腰椎部位的椎间关节主要承载身体的重量和背部肌肉产生的张力。背部肌肉的主要功能是产生与外力和惯性刀相抗衡的弯矩。椎间盘在矢状面运动中起支点作用。由于杠杆臂是恒定的,所以为身体重心前移产生的较大弯矩将对背部肌肉拖加较大的压力,相应地,椎间盘的承载也增大了,虽然我们知道肌肉运动对维持腰椎的稳定性起很重要的作用,但在体外对其进行模拟研究却较少见。本文选用一些研究者使用过的模型,探讨它们的生理意义,另外还提供了一种新的可结合对肌肉运动进行模拟的新模型,旨在对整个腰椎的矢状面运动情况进行模拟。为了证实模型的有效性,我们测试了一些腰椎尸体标本,将获得的节段间运动数据和椎间盘压力值与一些研究者的临床结果作了比较。     

皮质肌肉相干的影响因素及康复应用

皮质肌肉相干(CMC)是了解大脑皮质如何控制肌肉运动,以及评估大脑运动皮层与相关肌肉之间功能耦合的一种工具,在康复评估的相关研究中具有重要意义.从CMC的定义出发,概括了CMC在α、β与γ等3个主要频带的频率分布特征;从理论研究的角度,总结了作用力水平、年龄和病理状态等因素对CMC的影响;在CMC的应用研究方面,着重介...     

加压训练对中老年人肌肉适能的影响与优势

文题释义：加压训练(KAASTU Training)：是肢体近端束绑上加压带,施加适当压力并搭配小负荷抗阻运动,就能达到与传统高强度阻力运动相似的运动效果,其特点是负荷小、效果显著、安全系数较高。 肌肉适能(Muscle Fitness)：是指机体依靠肌肉收缩克服和对抗阻力维持身体运动的能力。通常表现为肌肉力量与肌肉耐力,良好的肌肉适能对于维持人体正常姿势、进行日常活动、保持身体健康有重要意义。 背景：加压训练具有结合小负荷运动就可以达到与传统高强度抗阻运动类似的训练效果,故而近年来广泛应用在竞技体育、运动健身、医疗康复等领域,但加压训练对中老年人肌肉适能影响有关的评述鲜见。 目的：通过对国内外加压运动对中老年人肌肉适能的全面综述,进一步解释及验证加压训练在中老年人运动中的安全性、实用性及便捷性,为中老年人选择安全有效的运动方式提供科学的建议。 方法：搜寻截止至 2019 年 10月,包括 Elsevier、PubMed、Springer、维普中文期刊服务平台、CNKI 中文资料总库的文献数据库以及台湾学术文献数据库,检索有关加压训练、血流限制、肌肉适能等的中英文文献,并根据研究需要确立相应的入选标准,对最终所得文献进行筛选。 结果与结论：①加压结合小负荷运动能够有效提高中老年人的肌肉量,对于预防中老年人肌肉萎缩有着正向效益;②加压训练结合小负荷运动能有效提高下肢肌力,有利于减少运动损伤,提高生活质量;③加压训练对中老年人骨健康有正向效益,对于改善老年人骨质疏松、提升骨密度有促进作用;④相较于传统抗阻训练,加压训练具有负荷小,效果好的特点,更容易被中老年人接受。 ORCID: 0000-0001-8540-0000(赵静) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

基于二次规划的人体屈伸运动肌肉力预测研究

目的研究人体屈伸运动过程中的肌肉力。方法在"中国力学虚拟人"模型的基础上,确定屈伸运动中参与运动肌肉束的生理横截面积及附着点的起止位置,建立完整的人体胸腰部骨肌系统模型。利用NDI运动捕捉系统获取脊柱形状的变化,利用肌电测量系统采集运动中肌肉的肌电信号规律。采用二次规划方法对不同运动速度和不同负载下的肌肉力进行优化预测。结果通过二次规划法预测出的肌肉力与肌电信号具有较好的一致性。结论该方法可以有效地预测人体屈伸运动中的肌肉力,对深入了解肌肉的运动机理,预防和减少运动损伤发生具有重要意义。     

拮抗肌对运动单位平均发放率的变化关系研究

“共驱动”现象是近年来提出的探索人体随意运动过程中神经系统控制机理的新概念,通过对肘关节恒力收缩时主动肌和拮抗肌两种针电极肌电图（NEMG）信号的分解,估计运动单位（MU）的平均发放率（FR）,研究单块肌肉和拮抗肌对运动单位平均发放率随时间的变化趋势和相关关系,实验结果表明,无论肘关节作屈曲和伸展时,主动肌和拮抗肌两者的运动单位平均发放率均随时间而下降且无相移地高度相关,从而从关节水平上论证了神经肌肉系统“共驱动”现象的存在。     

肌肉共同收缩对手臂屈伸运动末端阻抗的影响

目的 阻抗控制在稳定性控制中起着重要的作用,本文以手臂屈伸运动为对象建模来研究人体的阻抗控制规律,从而为更高层次的运动认知与工具使用奠定基础。方法 本文对现有的人体运动控制进行了改进,运用神经肌肉骨骼模型及最优控制方法推导出共同收缩阻抗,并对仿真结果与原模型和实验数据进行了对比。结果 从对比图中可以看出,本文模型修正了原有模型刚度椭圆单调变化的不足,与实验数据更加吻合。结论 由此得到即使在手臂平面自由运动中,肌肉共同收缩对阻抗也有贡献的结论。     

基于表面肌电信号的不同步行速度下肌肉协同及肌肉功能网络分析

深入了解步行过程中的下肢肌肉协作机制是提高神经肌肉功能障碍患者步态康复疗效的关键。本文研究了步行速度的变化对下肢肌肉协同模式及肌肉功能网络的影响。招募了8名健康受试者分别以三种不同速度在跑步机上执行步行任务，同步采集右下肢8块肌肉的表面肌电信号（sEMG），通过非负矩阵分解（NNMF）方法提取肌肉协同模式，利用互信息（MI）方法分别构建alpha频段（8～13 Hz）、beta频段（14～30 Hz）和gamma频段（31～60 Hz）肌肉功能网络，引入复杂网络分析方法量化不同网络差异。肌肉协同分析提取到5个肌肉协同模式，步行速度的变化没有改变肌肉协同的数量，但导致了肌肉权值的变化；肌肉网络分析发现在同一速度下，高频段具有更低的全局效率和聚类系数，随着步行速度的增加，局部肌肉之间的连接强度增加。研究结果表明不同速度的步行运动存在不同的肌肉协同模式和肌肉功能网络，本研究为探索不同步行速度下肌肉协同机制提供了新的视野，有望为神经肌肉功能障碍患者的步态功能评估提供理论支撑。     

两种不同肌肉力求解算法的对比分析

目的 探究静态优化(static optimization, SO)算法和计算肌肉控制(computed muscle control, CMC)算法求解肌肉力结果的异同,为研究人员选择合适的肌肉力求解算法和横向对比不同研究的结果提供依据。方法 以4种不同速度下跑步的步态作为研究动作,分别利用SO和CMC算法求解单个步态周期中下肢主要肌肉的肌肉力和肌肉激活,并进行对比分析。结果 在参与跑步的10块主要肌肉中,除了胫骨前肌和股直肌外,两种算法求解的肌肉力和肌肉激活具有相似的变化曲线,且相关系数均在0.91以上,但SO算法求解的肌肉力峰值偏高,肌肉激活峰值的位置约有10 ms延迟。结论 在动作分析时,如果研究重点在肌肉发力的时序以及不同肌肉之间的贡献比时,两种算法的选择没有太大区别,建议选择简单高效的SO算法。在横向对比不同研究中SO和CMC算法求解的肌肉力和肌肉激活结果时,需要考虑两者的差异。     

肌肉萎缩与过氧化体增殖活化受体γ辅助活化因子1α的关系

背景：过氧化体增殖活化受体γ辅助活化因子1α(peroxisome proliferator-activated receptor γ coactivator 1α,PGC-1α)能调节骨骼肌的功能,包括有：线粒体的生物发生、底物氧化和肌纤维类型等,最近还有研究发现PGC-1α能够预防肌肉的萎缩。 目的：总结并讨论PGC-1α与肌肉萎缩之间的关系。 方法：由第一作者用计算机检索中国期刊全文数据库(CNKI：2000/2010)和Medline数据库(2000/2010),关键词分别为“肌肉萎缩,PGC-1α,运动”和“muscle atrophy,PGC-1α,exercise”。共检索到56篇文章,按纳入和排除标准对文献进行筛选,共纳入22篇文章。从PGC-1α与肌肉萎缩、运动与PGC-1α共2个方面进行总结。 结果与结论：PGC-1α表达增强能提高线粒体功能、人体的运动能力、降低氧化应激和抑制肌肉萎缩特异性基因的表达。说明运动可通过调节PGC-1α的表达来干预肌肉萎缩。     

用双向脉冲作选择性神经刺激的研究

双向脉冲选择性刺激是避免神经纤维电化学损伤、使肌肉平稳收缩、降低疲劳的有效电刺激模式。本文提出了单电极、双电极和三电极三种双向刺激模式,利用计算机模型仿真有效地实现了选择性刺激,并且利用蟾蜍的离体坐骨神经干在动物实验上验证了这几种方法的可行性。这些方法可望推进神经电刺激向临床应用迈进的步伐     

Bronchoprovocation testing in asthma

This article covers the relationships between BHR and airway inflammation. Recent evidence suggests that various commonly used bronchoprovocation challenges (BPCs) differ in their potential to serve as inflammatory biomarkers. The response to direct stimuli depends on the smooth muscle's response to the chemical, whereas in indirect challenges, the reaction is caused by the smooth muscle's responsiveness to the mediators induced by the stimuli. The information obtained from studies with BPC has provided insights into the pathogenesis and pathophysiology of asthma, and the relationships between airway inflammation and bronchial hyper-responsiveness.     

胸小肌蒂喙突骨瓣移位术的应用解剖

目的:为胸小肌喙突骨瓣移位术提供应用解剖资料.方法:观测65例肩胛骨的喙突形态及26具52侧防腐尸体胸小肌与喙突的解剖关系.结果:肩胛骨喙突大小为4.1×1.4×1.0cm,胸小肌止于喙突者80.8%,不止于喙突者11.5%,部分止于喙突者7.7%.结论:并非所有患者均有胸小肌喙突骨瓣移位术的解剖学良好条件.拟行此术前应考虑相应的替代手术方案.     

Magnitude and decay of stretch-induced enhancement of power output

There is ample evidence that the pre-stretching of a muscle enhances performance of the subsequent shortening or concentric contraction. The purpose of this study was to investigate this stretch-induced enhancement in terms of the effect of load on the magnitude and decay of the muscle's power output. Instantaneous, mean and peak power outputs were compared between concentric-only and rebound bench press throws at different loads. The maximal strength [1 RM=84.0 (10.5) kg] of 18 male subjects [21.1 (3.0) years, 87.2 (11.9) kg] was determined using an isoinertial Smith press machine. The results of this study indicate enhancement of concentric motion by prior eccentric muscle action (200–780% enhancement in the first 100 ms). However, the magnitude and temporal characteristics of this enhancement differed across loads. Using a lighter load produced greater initial enhancement (P<0.05) but the decay of this enhancement was more rapid. The heavier 80% 1 RM loading showed a later time to peak enhancement (80 ms versus 20 ms) and slower decay of the stretch induced augmentation (460 ms versus 260 ms). It is concluded that the degree of stretch–shorten cycle enhancement differs according to the load and the time-dependent characteristics of the motion. Electronic Publication     

神经纤维双向选择性刺激方法仿真研究

双向选择性刺激是避免神经纤维电化学损伤、使肌肉平稳收缩、降低疲劳的有效电刺激模式。利用计算机模型仿真，提出了单电极、双电极和三电极三种双向刺激模式，有效地实现了选择性刺激，推进了神经电刺激向临床应用迈进的步伐。     

Three-dimensional spatial tuning of neck muscle activation in humans

The complex structure of the neck musculoskeletal system poses challenges to understanding central nervous system (CNS) control strategies. Examining muscle activation patterns in relation to musculoskeletal geometry and three-dimensional mechanics may reveal organizing principles. We analyzed the spatial tuning of neck muscle electromyographic (EMG) activity while subjects generated moments in three dimensions. EMG tuning curves were characterized by their orientation (mean direction) and focus (spread of activity). For the four muscles that were studied (sternocleidomastoid, splenius capitis, semispinalis capitis and trapezius), EMG tuning curves exhibited directional preference, with consistent orientation and focus among 12 subjects. However, the directional preference (orientation) of three of the four neck muscles did not correspond to the muscle's moment arm, indicating that maximizing a muscle's mechanical advantage is not the only factor in determining muscle activation. The focus of muscle tuning did not change with moment magnitude, demonstrating that co-contraction did not increase with load. Axial rotation was found to have a strong influence on neck muscle spatial tuning. The uniform results among subjects indicate that the CNS has consistent strategies for selecting neck muscle activations to generate moments in specific directions; however, these strategies depend on three-dimensional mechanics in a complex manner. Electronic Publication     

A three-element model describes excised cat papillary muscle elasticity.

The three-element model for skeletal muscle has been widely applied to cardiac muscle. It consists of an active contractile element (CE) that represents the muscle's response to stimulation, in series with an elastic element (SE) and the CE and SE in parallel with another elastic element (PE). There have been problems in interpreting experimental data on muscle elasticity using this model. Data seem to indicate that SE force depends not only on instantaneous length, but also initial length; it is not only elastic. Recent experiments seem to indicate that the SE has time-varying properties; it is not passive. This paper formulates a three-element model in which phi(x) = alpha[e beta(x-x*)-1] governs the elastic elements, where phi = force, alpha, beta = spring constants, x = length, and x* = rest length, which avoids these problems. The SE and PE have the same properties. (Typical values: alpha approximately equals .045 g/mm2, beta approximately equals 5.9 mm-1 for cat papillary at 29 degrees C.). By accounting for the nonlinearity of the SE-PE interaction, this three-element model leads to predictions that agree with published data on excised papillary muscle's elastic properties.     

Diffuse lymphangioleiomyomatosis of lung: case report

In the article the case of diffuse lymphangioleiomyomatosis of the lung at 21 year-old women is described The disease has manifested on the 38th week of the pregnancy. Leiomyomas of others localizations were absent. The clinical course was malignant: in 22 days after disease's manifestation women had died. The possible mechanisms of uncontrolled proliferation of nonstriated muscle's elements and features of lymphangioleiomyoma's morphological diagnostics are discussed.     

Factors contributing to thixotropy of inspiratory muscles

Thixotropy is a passive property of the skeletal muscle dependent on the muscle's immediate history of contraction and length change. Thixotropic properties of inspiratory muscles, introduced by forceful muscle contraction at an inflated lung volume, cause an increased end-expiratory position (EEP) of the rib cage. We searched for factors contributing to the development of inspiratory muscle thixotropy in nine healthy subjects. Using induction plethysmography, we examined aftereffects on EEP of the duration of inspiratory muscle contraction and subsequent muscle relaxation. We also studied effects of inspiratory effort intensity measured by mouth pressure at different lung volumes. EEP elevation was noted subsequent to 5-s contraction followed by 2-s relaxation and was enhanced when conditioned at higher lung volumes with a strong inspiratory effort. Our results suggest four factors that influence inspiratory muscle thixotropy: (1) intensity of muscle contraction, (2) lung volume when contraction occurs, (3) duration of contraction, and (4) muscle relaxation.     

Reinnervation of the soleus muscle by its own or by an alien nerve

The rates of reinnervation of the rat soleus muscle by its own or an alien nerve were compared using physiological and morphological criteria. The muscle's own nerve was more effective than the alien nerve in establishing functional connections with the original endplates. The relative ineffectiveness of the alien nerve during early stages of reinnervation was more apparent using physiological rather than morphological criteria. Five to six weeks after nerve injury there was no longer any difference between the muscles supplied by either nerve.