Name: determining the electromyographic fatigue threshold following a single visit exercise test
Uploaded: 2015-07-27T14:00:00.000+00:00
Duration: 6 min
Description: Watch this Scientific Journal Video about Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test at JoVE.com

This project was funded by, in part, by start-up funds from Wayne State University to M.H. Malek.

所有的程序都为人类受试者批准的大学机构审查委员会。 1.准备参展的腿<ol><li>有参与者整齐地挽起短裤所需的腿部。然后用胶带将短裤从而使股四头肌肌肉群暴露和借鉴各地的参与者需要刮胡子的区域线。 </li><li>重要提示:有测试，而不是以前的前一天参加剃光的腿，因为这可确保没有茬口这可能与肌电信号干扰。 </li><li>一旦参与者已完成剃须腿部的所需区域，清理剃光面积与酒精擦，以确保没有残存的剃须凝胶（或奶油），它可以与肌电信号的干扰。 </li></ol> 2.测量腿的电极放置<ol><li>为了将肌电电极上的股外侧肌，使FOllowing测量<ol><li>有与会者站直面临的研究员。 </li><li>定位前脊柱髂优越（ASIS）和髌骨的侧面。该ASIS是髋骨;通过将手放在脐下腹部两侧触诊它。 </li><li>用卷尺，测量上面确定的两个位置之间的距离，并取该值的2/3就行从ASIS到髌骨的横向侧。注:http://www.seniam.org/:关于肌电电极安置的进一步的信息可以在SENIAM（表面肌电图肌肉的非侵入性评估）网址找到</li></ol></li></ol> 3.放置肌电电极的<ol><li>股外侧的位置已被确定后，将电极肌电图（大多数研究人员使用市售一次性银银电极氯），地点在股外侧肌无需拆卸粘合SH屈服。然后用钢笔标记，其中所述电极的凝胶部分与肌肉接触的区域。确保极间距离为20mm的中心到中心。 </li><li>用一张砂纸（60粗）的轻轻研磨这两方面来消除皮肤的表层。在此期间，请参加者的不适的水平。停止研磨，当参与者表示该地区是温暖的。 </li><li>与被蘸有酒精擦或酒精棉签毛巾清洁磨损领域。允许在腿上放置区的肌电电极之前进行干燥。 </li><li>将肌电电极上进行研磨的位点（ 图2）。小心不要对髂胫束（IT波段）的电极。请参与者收缩股四头肌的肌肉，以触诊股外侧。放置在肌肉的电极，以确保它不是对IT频带。注意:如果对IT乐队电极，肌电信号WOU当参与者被要求最大限度合同LD被挫伤。 </li><li>放置在一个多骨附着位点的参考电极（ 第三电极）如ASIS从而不与下肢的运动的运动回合期间干扰。 </li></ol> 4.检查肌电图信号<ol><li>在此之前开始运动试验，检查极间的阻抗。 注:这一步非常关键，因为如果信号有太多的噪音，然后在运动试验中收集的肌电图的数据将是无效的。 <ol><li>有参与者坐在椅子上，并连接EMG导致连接到参与者的腿部各自的电极。 </li><li>在这一点上，有与会者放松自己的腿，有肌肉无张力。然后，大约30秒的放松后，有参与者最大限度的收缩股四头肌肌肉持续5秒钟，然后回去做彻底的放松。 </li><li>当执行该任务的博韦（步骤4.1.2），记录在计算机上的参与者肌电信号。 </li><li>确保极间阻抗&lt;2000欧姆。此外，如果一个电压表可在实验室中，然后检查基线噪音并保持低于5μV。此外，设置取样频率在1000赫兹。 </li></ol></li></ol> 5.设定行动的功率自行车<ol><li>检查极间的阻抗后，已经从椅​​子到功率自行车参与者的举动。 </li><li>有参与者站在旁边的功率自行车，并提高他们的膝盖直到大腿与地面平行。然后让参与者持这一立场，并调整座椅高度来匹配相同的高度参与者的大腿。 </li><li>此后，有与会者坐在功率自行车的座位，然后踏板几次，同时询问他们是否有舒适的座椅高度。如果需要，调整座椅高度。 </li><li>确保THAT中的参与者的腿是接近满延用，每个踏板革命期间轻微的弯曲（〜5℃）的膝盖。 </li><li>在开始测试之前，有参与者戴上极地心脏监测仪，使心脏速率可以记录整个运动试验。 </li></ol> 6.执行肌电图疲劳阈协议<ol><li>有参与者开始循环，并逐步增加他们的节奏，以70转/分。那么功率输出的功率自行车增加至50 ​​W. </li><li>有与会者循环在这个功率输出大约2-3分钟。 注:这是一种低强度的运动，并将作为热身。 </li><li>预热期后，增加功率输出25瓦，每2分钟，直到参与者不再能够维持70转/分的节奏或要求该测试被停止。 注意:应该注意的是，运动试验中，肌电图信号被记录为10在每个2分阶段秒10-20，30-40，50-60，70-80，90-100秒的时代，和110-120 21。大多数肌电图系统将有一个选项可以设置自动记录在所需的时间间隔。因此，对于每个阶段应该有6个数据文件。 </li><li>一旦增量测试已经结束，有参加者在50进行冷却W.检查冷却的长度相当于其参与者的心脏回报率的值在热身阶段。通过使用极性心脏监测仪检查参与者的心脏监测这一点。 </li><li>一旦冷却完成后，取出EMG领导和有参与者走下功率自行车，回到椅子上。然后小心地取出电极肌电图，并用干净的毛巾蘸有外用酒精或酒精棉签擦拭地区。 </li></ol> 7.处理肌电信号<ol><li>测试完成后，亲CESS运动试验期间收集的，使得数据可被用来确定肌电疲劳阈值的原始肌电图数据文件。 <ol><li>无论使用哪种用于收集肌电信号的软件或使用各种平台如MATLAB或LabVIEW的定制编写的软件进行肌电信号处理。 </li><li>过滤用的带通滤波器所收集的EMG信号。使用10设置到500赫兹。注意:此改变，使得低频率引起的伪像的肌电图信息（&lt;10赫兹）和高频人为从环境运动（&gt; 500赫兹），将被删除的信号的频率。使用60Hz的陷波滤波器，如果有从计算机或肌电图系统的电源的任何干扰。 </li><li>一旦信号已经被过滤，通过计算均方根信号的平方值确定的信号振幅:方形每个数据点，通过数据点的数目求和它们，除，再取所得值的平方根。执行这些计算使用上述软件。 </li></ol></li></ol> 8.确定肌电图疲劳阈值每位参与者<ol><li>执行每个参与者以下步骤。 <ol><li>经过肌电图信号已被处理;使用统计程序（ 例如 :的GraphPad棱镜），并与用于试验的功率输出标记的第一列"时间"和随后的列。 </li><li>每个电源输出，填充在每个20秒的时间间隔相应的肌电振幅值。 </li><li>每个电源输出，分析的时间（x轴）与肌电振幅（y轴）与线性回归关系，以确定是否回归直线的斜率是显著从零（P &lt;0.05）差异。 </li><li>后进行线性回归分析所有功率输出，确定最高功率输出与非显著（P&gt; 0.05）斜率。 </li><li>然后确定第lowest功率输出与显著（P &lt;0.05）斜率。 </li><li>一旦这两个功率输出已经确定，将它们添加和除以2;所得功率输出是估计的肌电图疲劳阈值。 </li></ol></li></ol>

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The authors have nothing to disclose.

我们在这里提出对确定神经肌肉股四头肌疲劳的方法肌肉股四头肌动态运动。这种方法提供了一个简单的和非侵入性的方式使用表面肌电信号。此外，该方法的通用性，研究人员可以使其适应于行使其他模式，如在跑步机20。 从理论上讲，对于强度等于或低于肌电疲劳阈参与者应能维持锻炼workbout无限期12,13。布里斯科等 8证实为周期测力肌电图...

表面肌电图（EMG）是研究过程中等距1-3运动单位招聘，等速4-6，或连续7-10肌肉动作的一种非侵入性的方法。肌电图信号的振幅表示肌肉激活它由电机单元的数目激活的马达单元的燃烧率，或两者11。的肌电疲劳阈的概念被用来指示在其中个人可以无限期地行使不增加肌电振幅8的最高工作负荷。 重要的是要简要讨论的肌电疲劳阈原点。由DeVries医师等人 12的最初的研究涉及一种协议，它由多个（通常为3至4个）连续工作较量，其中肌电振幅对时间作图每个工作回合。然后，输出功率为作图从EMG幅度的斜率系数随时间RELA<html> tionship，然后外推至零斜率（y截距）12。笔者原本12被称为该协议的实际工作能力，在疲劳阈值（PWCFT）。在另一项研究中，DeVries医师等 13间断使用一阵阵的工作，但使用的是线性回归找到第一动力输出，导致了肌电图振幅随时间的关系显著斜率。作者13也被称为该协议的PWCFT，开创了文学有些混乱。在随后的文章中，DeVries医师等 14修改他们早先的协议13，并制定了持续渐进的协议。肌电振幅对时间作图的每个功率输出和PWCFT被定义为输出功率最高的，导致在肌电振幅没有随时间的变化和功率输出最低，导致增加的EMG振幅随着时间的推移14的平均。 耳鼻喉科"&gt;应当指出的是，预委会最初引入在20世纪50年代后期15,16和术语是同义的过多文献（过去，现在，和在不同的国家）检查在给定的工作负载17有氧能力，此外，这个词用在人体工程学和工业文献其中重点为期8个小时工作日内完成重复性动作工人一天到一天的工作效率，例如在一个组装厂18个人。 术语肌电疲劳阈最初使用由Matsumoto和同事19它们改性的DeVries医师12协议，其中所述功率输出与所述EMG振幅对时间关系的斜率系数被绘制并外推至零斜率的点之后。最近，古费等人 20和布里斯科等人 8使用DeVries医师等人 14的方法和Matsumoto 等一个术语负于19操作性定义肌电图疲劳阈值。展望未来，我们建议长期EMG疲劳阈值来使用。因此，EMG振幅对时间的关系，绘制用于 ​​每个输出功率并使用线性回归分析（ 图1）进行分析。为了估计肌电疲劳阈值时，功率输出最高与非显著（P&gt; 0.05）的斜率和功率输出最低有显著（P &lt;0.05）斜率被确定，然后计算平均值14。这个协议是简单，方便，并在15-20分钟内完成。此外，增量速率可以基于惯常的体力活动的个体的水平进行调制，并且因此具有在临床应用潜力。

<table><tbody><tr><td>839 E Monark cycle ergometer&amp;nbsp;</td><td>Monark Exercise AB</td><td>839 E</td><td></td></tr><tr><td>Heart rate monitor</td><td>Polar</td><td>Polar H1</td><td></td></tr><tr><td>Laptop</td><td>Dell Inspiron</td><td>varies</td><td>any laptop computer with USB slots should work.</td></tr><tr><td>EMG amplifiers</td><td>BioPac Systems, Inc.</td><td>100B</td><td>100C are the latest version</td></tr><tr><td>Disposable EMG electrodes</td><td>BioPac Systems, Inc.</td><td>EL-500</td><td></td></tr><tr><td>Sandpaper</td><td>Home Depot</td><td>9 inch x 11 inch 60 Grit course no-slip grip Advanced Sandpaper (3-Pack)</td><td></td></tr></tbody></table>

determining the electromyographic fatigue threshold following a single visit exercise test

从理论上讲，肌电图（EMG）疲劳阈是运动强度个人可以无限期地保持，而不需要招募其与增加的肌电振幅相关联的更多的运动单位。虽然不同的协议已被用于估计肌电疲劳阈它们需要多次访问这是不切实际的临床环境。在这里，我们提出了一个协议，用于估算周期测力肌电图疲劳阈值，需要一个单一的访问。这个协议是简单，方便，并在15-20分钟内完成，因此，具有将其转化为临床医生在运动处方可以使用工具的潜力。

如图1，对于单个参与者，即完成了每个功率输出具有代表肌电振幅为股外侧肌的六个数据点。因此，在这个例子中，最高功率输出与非显著（P&gt; 0.05）斜率为200瓦，而动力输出最低有显著（P &lt;0.05）斜率为225 W.因此，对于该与会者的肌电疲劳阈是213 W·一旦肌电疲劳阈值确定每个参与者然后推论统计可以被执行。 <...

Watch this Scientific Journal Video about Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test at JoVE.com

Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test

This protocol describes the electromyographic fatigue threshold which demarcates between nonfatiguing and fatiguing exercise workloads. This information could be used to develop a more individualized training program.

确定肌电疲劳阈值以下单次访问运动试验

Theoretically, the electromyographic (EMG) fatigue threshold is the exercise intensity an individual can maintain indefinitely without the need to recruit ...

determining-electromyographic-fatigue-threshold-following-single

Research

JoVE Journal

Medicine

12.5K 次观看.  Wayne State University. This protocol describes the electromyographic fatigue threshold which demarcates between nonfatiguing and fatiguing exercise workloads. This information could be used to develop a more individualized training program.

视频: Determining The Electromyographic Fatigue Threshold Following a Single Visit Exercise Test

Utilizing Transcranial Magnetic Stimulation to Study the Human Neuromuscular System

Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade. While the use of TMS has expanded to the study of many systems and processes during this time, the original application and perhaps one of the most common uses of TMS involves studying the physiology, plasticity and function of the human neuromuscular system. Single pulse TMS applied to the motor cortex excites pyramidal neurons transsynaptically 2 (Figure 1) and results in a measurable electromyographic response that can be used to study and evaluate the integrity and excitability of the corticospinal tract in humans 3. Additionally, recent advances in magnetic stimulation now allows for partitioning of cortical versus spinal excitability 4,5. For example, paired-pulse TMS can be used to assess intracortical facilitatory and inhibitory properties by combining a conditioning stimulus and a test stimulus at different interstimulus intervals 3,4,6-8. In this video article we will demonstrate the methodological and technical aspects of these techniques. Specifically, we will demonstrate single-pulse and paired-pulse TMS techniques as applied to the flexor carpi radialis (FCR) muscle as well as the erector spinae (ES) musculature. Our laboratory studies the FCR muscle as it is of interest to our research on the effects of wrist-hand cast immobilization on reduced muscle performance6,9, and we study the ES muscles due to these muscles clinical relevance as it relates to low back pain8. With this stated, we should note that TMS has been used to study many muscles of the hand, arm and legs, and should iterate that our demonstrations in the FCR and ES muscle groups are only selected examples of TMS being used to study the human neuromuscular system.

Transcranial magnetic stimulation (TMS) is a non-invasive tool to gain insight on the physiology and function of the human nervous system. Here, we present our TMS techniques to study cortical excitability of the upper limb and lumbar musculature.

利用经颅磁刺激，以研究人类的神经肌肉系统

Transcranial magnetic stimulation (TMS) has been in use for more than 20 years 1, and has grown exponentially in popularity over the past decade.  While ...

科研

医学

Force and Position Control in Humans - The Role of Augmented Feedback

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is constantly integrated into the central nervous system and these sensory inputs need to be weighted in order meet the task specific goals. Additional feedback presented as augmented feedback was shown to have an impact on motor control and motor learning. A number of studies investigated whether force or position feedback has an influence on motor control and neural activation. However, as in the previous studies the presentation of the force and position feedback was always identical, a recent study assessed whether not only the content but also the interpretation of the feedback has an influence on the time to fatigue of a sustained submaximal contraction and the (inhibitory) activity of the primary motor cortex using subthreshold transcranial magnetic stimulation. This paper describes one possible way to investigate the influence of the interpretation of feedback on motor behaviour by investigating the time to fatigue of submaximal sustained contractions together with the neuromuscular adaptations that can be investigated using surface EMG. Furthermore, the current protocol also describes how motor cortical (inhibitory) activity can be investigated using subthreshold TMS, a method known to act solely on the cortical level. The results show that when participants interpret the feedback as position feedback, they display a significantly shorter time to fatigue of a submaximal sustained contraction. Furthermore, subjects also displayed an increased inhibitory activity of the primary cortex when they believed to receive position feedback compared when they believed to receive force feedback. Accordingly, the results show that interpretation of feedback results in differences on a behavioural level (time to fatigue) that is also reflected in interpretation-specific differences in the amount of inhibitory M1 activity.

Controlling an identical movement with position or force feedback results in different neural activation and motor behavior. This protocol describes how to investigate behavioral changes by looking at neuromuscular fatigue and how to evaluate motor cortical (inhibitory) activity using subthreshold TMS with respect to the interpretation of augmented feedback.

力和位置控制人类 - 增强反馈的作用

During motor behaviour, humans interact with the environment by for example manipulating objects and this is only possible because sensory feedback is ...

行为学

Measuring the Motor Aspect of Cancer-Related Fatigue using a Handheld Dynamometer

Cancer-related fatigue (CRF) is commonly reported by patients both during and after receiving treatment for cancer. Current CRF diagnoses rely on self-report questionnaires which are subject to report and recall biases. Objective measurements using a handheld dynamometer, or handgrip device, have been shown in recent studies to correlate significantly with subjective self-reported fatigue scores. However, variations of both the handgrip fatigue test and fatigue index calculations exist in the literature. The lack of standardized methods limits the utilization of the handgrip fatigue test in the clinical and research settings. In this study, we provide detailed methods for administering the physical fatigue test and calculating the fatigue index. These methods should supplement existing self-reported fatigue questionnaires and help clinicians assess fatigue symptom severity in an objective and quantitative manner.

Simple and accessible methods were developed to measure the motor aspect of cancer-related fatigue objectively and quantitatively. We describe, in detail, ways to administer the physical fatigue test using a simple handgrip device as well as methods to calculate fatigue indices.

使用手持测功机测量癌症相关疲劳的马达方面

Cancer-related fatigue (CRF) is commonly reported by patients both during and after receiving treatment for cancer. Current CRF diagnoses rely on ...

癌症研究

Standing Neurophysiological Assessment of Lower Extremity Muscles Post-Stroke

Transcranial magnetic stimulation (TMS) is a common tool used to measure the behavior of motor circuits in healthy and neurologically impaired populations. TMS is used extensively to study motor control and the response to neurorehabilitation of the upper extremities. However, TMS has been less utilized in the study of lower extremity postural and walking-specific motor control. The limited use and the additional methodological challenges of lower extremity TMS assessments have contributed to the lack of consistency in lower extremity TMS procedures within the literature. Inspired by the decreased ability to record lower extremity TMS motor evoked potentials (MEP), this methodological report details steps to enable post-stroke TMS assessments in a standing posture. The standing posture allows for the activation of the neuromuscular system, reflecting a state more akin to the system's state during postural and walking tasks. Using dual-top force plates, we instructed participants to equally distribute their weight between their paretic and non-paretic legs. Visual feedback of the participants' weight distribution was provided. Using image guidance software, we delivered single TMS pulses via a double-cone coil to the participants' lesioned and non-lesioned hemispheres and measured the corticomotor response of the paretic and non-paretic tibialis anterior and soleus muscles. Performing assessments in the standing position increased the TMS response rate and allowed for the use of the lower stimulation intensities compared to the standard sitting/resting position. Utilization of this TMS protocol can provide a common approach to assess the lower extremity corticomotor response post-stroke when the neurorehabilitation of postural and gait impairments are of interest.

This protocol describes the process for performing a neurophysiological assessment of the lower extremity muscles, tibialis anterior and soleus, in a standing position using TMS in people post-stroke. This position provides a greater probability of eliciting a post-stroke TMS response and allows for the use of reduced stimulator power during neurophysiological assessments.

中风后下肢肌肉的站立神经生理学评估

Transcranial magnetic stimulation (TMS) is a common tool used to measure the behavior of motor circuits in healthy and neurologically impaired ...

Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study

Execution of Sit-to-Stand (SitTS) in incomplete spinal cord injury (SCI) patients involves motor function in both upper and lower extremities. The use of arm support, in particular, is a significant assistive factor while executing SitTS movement in SCI population. In addition, the application of functional electrical stimulation (FES) onto quadriceps and gluteus maximus muscles is one of the prescribed management for incomplete SCI to improve muscle action for simple lower limb movements. However, the relative contribution of upper and lower extremities during SitTS has not been thoroughly investigated. Two motor incomplete SCI paraplegics performed repetitive SitTS to fatigue exercise challenge. Their performance was investigated as a mixed-method case-control study comparing SitTS with and without the assistance of FES. Three sets of SitTS tests were completed with 5-min resting period allocated in between sets, with mechanomyography (MMG) sensors attached over the rectus femoris muscles bilaterally. The exercise was separated into 2 sessions; Day 1 for voluntary SitTS and Day 2 for FES-assisted SitTS. Questionnaires were conducted after every session to gather the participants&#39; input about their repetitive SitTS experience. The analysis confirmed that a SitTS cycle could be divided into three phases; Phase 1 (Preparation to stand), Phase 2 (Seat-off), and Phase 3 (Initiation of hip extension), which contributed to 23% &#177; 7%, 16% &#177; 4% and 61% &#177; 6% of the SitTS cycle, respectively. The contribution of arms and legs during SitTS movement varied in different participants based on their legs&#39; Medical Research Council (MRC) muscle grade. In particular, the applied arm forces start to increase clearly when the leg forces start to decline during standing. This finding is supported by the significantly reduced MMG signal indicating leg muscle fatigue and their reported feeling of tiredness.

Arms contribution in Sit-To-Stand (SitTS) is determined by the legs' muscle condition. Several compensating strategies were discovered in efforts to achieve complete SitTS cycles. These findings triangulate the spinal cord injury (SCI) persons' biomechanical measures with their subjective feeling of load borne by both their limbs throughout the SitTS approaches.

量化截瘫患者重复性电动辅助坐立锻炼期间手臂和腿部的贡献:一项试点研究

Execution of Sit-to-Stand (SitTS) in incomplete spinal cord injury (SCI) patients involves motor function in both upper and lower extremities. The use of ...

工程学

Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation

Percutaneous electrical nerve stimulation is a non-invasive method commonly used to evaluate neuromuscular function from brain to muscle (supra-spinal, spinal and peripheral levels). The present protocol describes how this method can be used to stimulate the posterior tibial nerve that activates plantar flexor muscles. Percutaneous electrical nerve stimulation consists of inducing an electrical stimulus to a motor nerve to evoke a muscular response. Direct (M-wave) and/or indirect (H-reflex) electrophysiological responses can be recorded at rest using surface electromyography. Mechanical (twitch torque) responses can be quantified with a force/torque ergometer. M-wave and twitch torque reflect neuromuscular transmission and excitation-contraction coupling, whereas H-reflex provides an index of spinal excitability. EMG activity and mechanical (superimposed twitch) responses can also be recorded during maximal voluntary contractions to evaluate voluntary activation level. Percutaneous nerve stimulation provides an assessment of neuromuscular function in humans, and is highly beneficial especially for studies evaluating neuromuscular plasticity following acute (fatigue) or chronic (training/detraining) exercise.

We present a protocol to assess changes in neuromuscular function. Percutaneous electrical nerve stimulation is a non-invasive method that evokes muscular responses. Electrophysiological and mechanical properties of these responses permit the evaluation of neuromuscular function from brain to muscle (supra-spinal, spinal and peripheral levels).

神经肌肉功能的应用经皮神经电刺激评估

Percutaneous electrical nerve stimulation is a non-invasive method commonly used to evaluate neuromuscular function from brain to muscle (supra-spinal, ...

神经科学

Measuring Neuromuscular Junction Functionality

Neuromuscular junction (NMJ) functionality plays a pivotal role when studying diseases in which the communication between motor neuron and muscle is impaired, such as aging and amyotrophic lateral sclerosis (ALS). Here we describe an experimental protocol that can be used to measure NMJ functionality by combining two types of electrical stimulation: direct muscle membrane stimulation and the stimulation through the nerve. The comparison of the muscle response to these two different stimulations can help to define, at the functional level, potential alterations in the NMJ that lead to functional decline in muscle.
Ex vivo preparations are suited to well-controlled studies. Here we describe an intensive protocol to measure several parameters of muscle and NMJ functionality for the soleus-sciatic nerve preparation and for the diaphragm-phrenic nerve preparation. The protocol lasts approximately 60 min and is conducted uninterruptedly by means of a custom-made software that measures the twitch kinetics properties, the force-frequency relationship for both muscle and nerve stimulations, and two parameters specific to NMJ functionality, i.e. neurotransmission failure and intratetanic fatigue. This methodology was used to detect damages in soleus and diaphragm muscle-nerve preparations by using SOD1G93A transgenic mouse, an experimental model of ALS that ubiquitously overexpresses the mutant antioxidant enzyme superoxide dismutase 1 (SOD1).

A functional assessment of the neuromuscular junction (NMJ) can provide essential information on the communication between muscle and nerve. Here we describe a protocol to comprehensively evaluate both the NMJ and muscle functionality using two different muscle-nerve preparations, i.e. soleus-sciatic and diaphragm-phrenic.

测量神经肌肉接头功能

Neuromuscular junction (NMJ) functionality plays a pivotal role when studying diseases in which the communication between motor neuron and muscle is ...

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

Described here is a method to measure contractility of isolated skeletal muscles. Parameters such as muscle force, muscle power, contractile kinetics, fatigability, and recovery after fatigue can be obtained to assess specific aspects of the excitation-contraction coupling (ECC) process such as excitability, contractile machinery and Ca2+ handling ability. This method removes the nerve and blood supply and focuses on the isolated skeletal muscle itself. We routinely use this method to identify genetic components that alter the contractile property of skeletal muscle though modulating Ca2+ signaling pathways. Here, we describe a newly identified skeletal muscle phenotype, i.e., mechanic alternans, as an example of the various and rich information that can be obtained using the in vitro muscle contractility assay. Combination of this assay with single cell assays, genetic approaches and biochemistry assays can provide important insights into the mechanisms of ECC in skeletal muscle.

Ex Vivo Assessment of Contractility, Fatigability and Alternans in Isolated Skeletal Muscles

We describe a method to directly measure muscle force, muscle power, contractile kinetics and fatigability of isolated skeletal muscles in an in vitro system using field stimulation. Valuable information on Ca2+ handling properties and contractile machinery of the muscle can be obtained using different stimulating protocols.

体外评估对离体骨骼肌的收缩，疲劳性和交替“

 
Described here is a method to measure contractility of isolated skeletal muscles. Parameters such as muscle force, muscle power, contractile kinetics, ...

生物学

Conducting Maximal and Submaximal Endurance Exercise Testing to Measure Physiological and Biological Responses to Acute Exercise in Humans

Regular physical activity has a positive effect on human health, but the mechanisms controlling these effects remain unclear. The physiologic and biologic responses to acute exercise are predominantly influenced by the duration and intensity of the exercise regimen. As exercise is increasingly thought of as a therapeutic treatment and/or diagnostic tool, it is important that standardizable methodologies be utilized to understand the variability and to increase the reproducibility of exercise outputs and measurements of responses to such regimens. To that end, we describe two different cycling exercise regimens that yield different physiologic outputs. In a maximal exercise test, exercise intensity is continually increased with a greater workload resulting in an increasing cardiopulmonary and metabolic response (heart rate, stroke volume, ventilation, oxygen consumption and carbon dioxide production). In contrast, during endurance exercise tests, the demand is increased from that at rest, but is raised to a fixed submaximal exercise intensity resulting in a cardiopulmonary and metabolic response that typically plateaus. Along with the protocols, we provide suggestions on measuring physiologic outputs that include, but are not limited to, heart rate, slow and forced vital capacity, gas exchange metrics, and blood pressure to enable the comparison of exercise outputs between studies. Biospecimens can then be sampled to assess cellular, protein, and/or gene expression responses. Overall, this approach can be easily adapted into both short- and long-term effects of two distinct exercise regimens.

To assess the influence of exercise intensity on physiologic and biologic responses, two different exercise testing protocols were utilized. Methods outlining exercise testing on a cycle ergometer as an incremental maximal oxygen consumption test and endurance, steady state submaximal endurance test are described.

进行最大和次极大耐力运动测试, 测量人类急性运动的生理和生物学反应

Regular physical activity has a positive effect on human health, but the mechanisms controlling these effects remain unclear. The physiologic and biologic ...

Determining the Functional Status of the Corticospinal Tract Within One Week of Stroke

High interindividual variability in the recovery of upper limb (UL) function after stroke means it is difficult to predict an individual&#39;s potential for recovery based on clinical assessments alone. The functional integrity of the corticospinal tract is an important prognostic biomarker for recovery of UL function, particularly for those with severe initial UL impairment. This article presents a protocol for evaluating corticospinal tract function within 1 week of stroke. This protocol can be used to select and stratify patients in trials of interventions designed to improve UL motor recovery and outcomes after stroke. The protocol also forms part of the PREP2 algorithm, which predicts UL function for individual patients 3 months poststroke. The algorithm sequentially combines a UL strength assessment, age, transcranial magnetic stimulation, and stroke severity, within a few days of the stroke. The benefits of using PREP2 in clinical practice are described elsewhere. This article focuses on the use of a UL strength assessment and transcranial magnetic stimulation to evaluate corticospinal tract function.

This protocol is for evaluating corticospinal tract function within 1 week of stroke. It can be used to select and stratify patients in trials of interventions designed to improve upper limb motor recovery and outcomes and in clinical practice for predicting upper limb functional outcomes 3 months after stroke.

确定中风一周内皮质脊柱的功能状态

High interindividual variability in the recovery of upper limb (UL) function after stroke means it is difficult to predict an individual&#39;s potential ...