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

すべての手順は、ヒト対象のための大学の施設内倫理委員会によって承認されました。 参加者の脚の調製<ol><li>参加者がきちんと目的の脚のために彼らのパンツをロールアップしています。大腿四頭筋は筋群が露出し、参加者が剃る必要のある領域の周りに線を描画されている大腿ように、そしてパンツをテープで固定します。 </li><li>重要：これはEMG信号を妨害する可能性がないstubblesがないことを保証するよう、参加者がテストではなく、前の日の前に自分の足を剃るてもらいます。 </li><li>参加者は、脚の所望の領域を剃る終了すると、EMG信号を妨害することがシェービングジェル（またはクリーム）のない残骸がないことを確認するために消毒用アルコールで剃毛面積を清掃してください。 </li></ol>電極配置のための脚の2測定<ol><li>外側広筋の筋のEMG電極を配置するためには、FOを作りますllowing測定<ol><li>参加者は研究者が直面しているまっすぐに立っています。 </li><li>優れた（ASIS）腸骨前方脊椎と膝蓋骨の側方を探します。 ASISは、股関節の骨です。臍下の腹部の両側に手を置くことによって、それを触診。 </li><li>巻尺を使用すると、上記識別される2つの位置の間の距離を測定し、膝蓋骨の側方へのASISから行にその値の2/3を取ります。注：http://www.seniam.org/：EMG電極の配置に関するさらなる情報は、SENIAM（筋肉の非侵襲的評価のための表面筋電図）URLで見つけることができます</li></ol></li></ol> EMG電極の3配置<ol><li>外側広筋の位置が特定された後、接着SHを除去せずに外側広筋上のEMG電極（ほとんどの研究者は、市販の使い捨てのAg-Ag系のCl電極を使用）と起こりますield。そして、ペンで電極のゲル部分は、筋肉と接触する領域をマーク。電極間距離が20mmの中心であることを確認してください。 </li><li>優しく皮膚の表面層を除去するために、この2つの領域を研磨するためにサンドペーパー（60粗い）の一部を使用してください。この間、参​​加者に不快感のレベルを求めます。参加者は地域が暖かい示すとき研磨を停止します。 </li><li>アルコールまたはアルコール綿棒をこすりを浸したタオルで摩耗領域を清掃してください。脚部の面積はEMG電極を配置する前に乾燥することができます。 </li><li> （ 図2）研磨されたサイトにEMG電極を配置します。腸脛靱帯（IT帯）に電極を配置しないように注意してください。外側広筋を触診するために、大腿四頭筋を収縮し、参加者を確認して下さい。それはIT帯にされないようにするために、筋肉に電極を配置します。注：ITバンドの電極場合、EMG信号wou参加者が契約を最大限にするように求められたときにLDは減衰させること。 </li><li>このようなASISは、このように、運動の試合中に下肢の動きに干渉しないようBONEYの付着部位の基準電極（ 第 3 電極 ）を配置します。 </li></ol> 4. EMG信号の確認<ol><li>運動負荷試験を開始する前に、極間インピーダンスを確認してください。 注：信号があまりにも多くのノイズを持っているならば、運動負荷試験中に収集されたEMGデータは無効となりますので、このステップは非常に重要です。 <ol><li>参加者が椅子に座って、EMGは、参加者の脚部に取り付けられ、それぞれの電極につながる接続しています。 </li><li>この時点で、参加者は筋肉には緊張を有していない、彼らの足をリラックスできます。そして緩和の約30秒後に、参加者は最大5秒間その大腿四頭筋を収縮させ、その後、完全にリラックスしているに戻っています。 </li><li>タスクAを実行する場合BOVE（ステップ4.1.2）、コンピューター上で参加者EMG信号を記録します。 </li><li>極間インピーダンスが&lt;2,000オームであることを確認してください。電圧計は、実験室で利用可能である場合また、その後、ベースラインノイズをチェックして、5μV以下に保ちます。また、千Hzのサンプリング周波数を設定します。 </li></ol></li></ol> 5.設定アップサイクルエルゴメーター<ol><li>極間インピーダンスを確認した後、サイクルエルゴメーターに椅子からの参加者の動きを持っています。 </li><li>参加者は、サイクルエルゴメーターの隣に立って、太ももが地面と平行になるまで自分の膝を上げています。その後、参加者は、この位置を保持し、参加者の大腿部と同じ高さに合わせて、シートの高さを調整しています。 </li><li>その後、参加者は、サイクルエルゴメーター席に座ると、彼らはシートの高さに慣れている場合は、それらを求めながら、数回のペダルがあります。必要に応じて、座面の高さを調整します。 </li><li> THAを確認参加者の足T各ペダル回転中に膝のわずかな曲がり（〜5°）との完全な拡張子の近くにあります。 </li><li>心拍数は、運動試験にわたって文書化することができるようにテストを開始する前に、参加者は、極性心拍数モニタを着用しています。 </li></ol> 6. EMG疲労しきい値のプロトコルを実行します<ol><li>参加者は、サイクリングを開始し、徐々に/分70回転にそのリズムを増やす必要があります。次に、50 Wにサイクルエルゴメーターの電源出力を増加させます</li><li>約2〜3分間、このパワー出力で参加者のサイクルを持っています。 注：これは、低強度の運動であり、ウォームアップとして機能します。 </li><li>参加者は、もはや70回転/分のリズムを維持することができるか、試験を中止することを要求するまでのウォームアップ期間の後、毎分2 W 25による電力出力を増加しません。 注：これは、運動試験中に、EMG信号が10のために記録されることに留意されたいです秒秒10-20、30-40、50-60、70-80、90-100のための各2分の段階でエポック、および110〜120 21。ほとんどのEMGシステムは、所望の間隔で自動記録を設定するオプションがあります。このように、各ステージのための6つのデータファイルがあるはずです。 </li><li>増分テストが終了した後、参加者は50 W.でクールダウン実行しているクールの長さダウンがウォームアップフェーズの間に値に参加者の心拍数の戻りを有する対応することを確認してください。極性の心拍数モニターを使用して、参加者の心拍数をチェックして、これを監視します。 </li><li>クールダウンが完了すると、EMGリード削除し、参加者が、サイクルエルゴメーターを降りると椅子に戻っています。その後、慎重にEMG電極を除去し、アルコールまたはアルコール綿棒をこすりで湿らせた清潔なタオルでエリアを拭いてください。 </li></ol> 7. EMG信号を処理<ol><li>テストが完了すると、プロデータはEMG疲労閾値を決定するために使用することができるように運動負荷試験中に収集された生EMGデータファイルをCESS。 <ol><li> EMG信号を収集するために使用されるソフトウェアや、MATLABやLabVIEWのような様々なプラットフォームを使用してカスタム書かれたソフトウェアのいずれかでEMG信号の処理を実行します。 </li><li>バンドパスフィルターを用いて収集EMG信号をフィルタ。 10〜500ヘルツの設定を使用します。注：これは、&lt;環境から（10ヘルツ、高周波アーチファクトEMGリード）の動き（&gt; 500ヘルツ）の低周波数アーチファクトが除去されるように、信号の周波数を変化させます。コンピュータまたはEMGシステムの電源からの干渉がある場合には60Hzのノッチフィルタを使用してください。 </li><li>信号がフィルタリングされた後、信号の二乗値を平均平方根を計算することによって信号の振幅を決定する：正方形のデータ点のそれぞれは、それらを合計し、データポイントの数で除算し、次いで、得られた値の平方根を取ります。上記のソフトウェアを使用してこれらの計算を実行します。 </li></ol></li></ol> 8.各参加者のEMG疲労閾値を決定します<ol><li>参加者ごとに以下の手順を実行します。 <ol><li> EMG信号は、処理された後、統計プログラム（ 例 ：グラフパッドプリズム）を使用し、テストのために使用される電力出力と最初の列「時間」とそれに続く列にラベルを付けます。 </li><li>各電力出力の場合は、フィルイン、各20秒間隔での対応EMG振幅値。 </li><li>各電力出力は、回帰直線の傾きがゼロとは異なる（p &lt;0.05）有意であるかどうかを決定するために線形回帰とEMG振幅（y軸）の関係対時間（x軸）を分析します。 </li><li>線形回帰を実行すると、すべての電力出力のために分析した後、非有意（P&gt; 0.05）の傾きで最高の電力出力を識別します。 </li><li>そして、Lを識別に有意な（p &lt;0.05）の傾きを有するowest電力出力。 </li><li>これらの2つの電源出力が識別されると、それらを追加し、2で割ます。結果として得られる出力は推定EMG疲労閾値です。 </li></ol></li></ol>

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The authors have nothing to disclose.

ここでは、大腿四頭筋に神経筋疲労を決定するための方法は、動的運動のために筋肉を大腿提示します。この方法は、表面筋電図を用いて簡単にかつ非侵襲的なアプローチを提供します。また、この方法の汎用性は、研究者は、トレッドミル20のような運動の他のモードに適応させることができるということです。 理論的には、EMGの疲労閾値で以下の強度のため?...

表面筋電図（EMG）は、等角投影1-3時のモータユニットの動員、等速4-6、または連続7-10筋活動を研究する非侵襲的なアプローチです。 EMG信号の振幅は、活性運動単位の数は、モータユニットの発射速度、または両方の11から構成され、筋肉の活性化を表します。 EMG疲労閾値の概念は、個人がEMG振幅8を増加させることなく無制限に運動可能な最高の負荷を示すために使用されます。 これは、EMGの疲労閾値の起源について簡単に議論することが重要です。デブリーズら 12による最初の研究は、EMGの振幅が各作業の試合のための時間に対してプロットした（通常は3から4）不連続な作業の試合、複数から構成されたプロトコルを関与しました。電力出力は、その後、時間RELA対EMG振幅の傾き係数に対してプロットしました<html>シップ、およびゼロスロープ（y切片）12に外挿し。著者ら12はもともと、そのプロトコルに疲労閾値（PWCFT）での物理的な作業能力と呼ばれます。別の研究では、デブリーズら 13は、不連続作業発作を使用しますが、時間の関係に対するEMG振幅に大きな傾きが生じた第1の電力出力を見つけるために線形回帰を使用していました。著者ら13は 、文献にもいくつかの混乱を作成し、そのプロトコルPWCFTと呼ばれます。その後の記事では、デブリーズら 14は、それらの以前のプロトコル13を修正し、継続的な増分のプロトコルを開発しました。 EMG振幅は、各電源出力の時間に対してプロットし、PWCFTは時間をかけてEMG振幅に変化がないと時間14にわたってEMG振幅が増加した最低電力出力が得られた最高の電力出力の平均値として定義しました。 ENTは&quot;&gt;これは、PWCは、もともと1950年代後半15,16に導入された用語は、文献の過多（過去、現在、そして様々な国全体で）特定のワークロード17で有酸素能力を調べることと同義であることに留意されたい。また、この用語は、このような組立工場18内の個人として8時間の作業日の間に繰り返し動作を行う労働者の日々の生産性に焦点を当て、人間工学的および工業文献で ​​使用されています。 彼らは時間の関係に対するEMG振幅の傾き係数対パワー出力をプロットし、勾配がゼロに外挿するデブリーズ12プロトコルを変更した後、長期EMG疲労閾値は、最初は松本ら19で使用されていました。さらに最近では、ガフィーら 20とブリスコーら 8デブリーズらの方法を使用していました。14松本らaの用語運用EMG疲労しきい値を定義するには、l。19。今後は、用語EMG疲労閾値を使用することをお勧めします。したがって、時間的関係に対するEMG振幅は各電力出力に対してプロットし、線形回帰分析（ 図1）を用いて分析しました。 EMG疲労閾値を推定するために、有意な（p &lt;0.05）と有意でない（p&gt; 0.05）、傾きおよび最低電力出力と最高出力が勾配が同定され、次いで、平均14を算出します。このプロトコルは、シンプル、便利、かつ15〜20分以内で完了です。さらに、増分率は習慣的な身体活動の個々のレベルに基づいて調節することができるので、臨床での潜在的用途を有します。

<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

理論的には、筋電（EMG）疲労閾値は、個人がEMGの振幅の増加に関連付けられている複数のモータユニットを補充することなく、無期限に維持することができる運動強度です。異なるプロトコルは、EMG疲労閾値を推定するために使用されてきたが、それらは、臨床設定では非実用的である複数の訪問を必要とします。ここでは、単一の訪問を必要とするサイクルエルゴメータ運動負荷試験法のためのEMG疲労閾値を推定するためのプロトコルを提示します。このプロトコルは、したがって、臨床医は運動処方に使用できるツールに翻訳される可能性を持っている、シンプルで便利で15〜20分以内で完了です。

図1に示すように、単一の参加者のために、完成された各出力は外側広筋の筋肉のためのEMG振幅を表す6つのデータ点を有します。重大と最低電力出力（P &lt;0.05）、傾きがこの参加者のためにEMG、したがって225 W.あるのに対ししたがって、この例では、非有意（P&gt; 0.05）、傾きの最高出力は200ワットでありますEMG疲労閾値はその後推測統計を行うことができ、各参加...

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.

シングル訪問運動試験後の電疲労閾値を決定します

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 ビュー.  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.

ビデオ: 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.

人間の神経筋システムを研究するために経頭蓋磁気刺激の活用

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 ...

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.

人間の力と位置制御 - 増補フィードバックの役割

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

行動学

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.

ハンドヘルドダイナモメーターを用いた癌関連疲労の運動面の測定

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

がん研究

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.

対麻痺患者における反復的な電気支援座位から立位への運動中の腕と脚の寄与の定量化:パイロット研究

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).

経皮的電気神経刺激を使用した神経筋機能の評価

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

神経科学

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.

神経筋接合部機能を測定

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.

隔離された骨格筋の収縮、倦怠感や交互の ex vivo での評価

 
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.

最大及び最大下運動生理・生物学的ヒトにおける急性運動レスポンスを測定するテストを実施

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

Functional Isolation of Single Motor Units of Rat Medial Gastrocnemius Muscle

This work outlines functional isolation of motor units (MUs), a standard electrophysiological method for determining characteristics of motor units in hindlimb muscles (such as the medial gastrocnemius, soleus, or plantaris muscle) in experimental rats. A crucial element of the method is the application of electrical stimuli delivered to a motor axon isolated from the ventral root. The stimuli may be delivered at constant or variable inter-pulse intervals. This method is suitable for experiments on animals at varying stages of maturity (young, adult or old). Moreover, this protocol can be used in experiments studying variability and plasticity of motor units evoked by a large spectrum of interventions. The results of these experiments may both augment basic knowledge in muscle physiology and be translated into practical applications. This procedure focuses on the surgical preparation for the recording and stimulation of MUs, with an emphasis on the necessary steps to achieve preparation stability and reproducibility of results.

This method allows the recording of the force of twitch and tetanic contractions and action potentials in three types of motor units in the rat medial gastrocnemius muscle. The functional isolation of a single motor unit is induced by electrical stimulation of the axon.

ラット内側胃腸筋単一運動ユニットの機能的分離

This work outlines functional isolation of motor units (MUs), a standard electrophysiological method for determining characteristics of motor units in ...

Muscle Function Obtained with Motion Mode Ultrasound and Surface Electromyography during Core Endurance Exercise

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured between fascial borders at a given time point during an exercise. This selected time point produces a one-dimensional image resulting in real-time, live observation of anatomy. Ultrasound used during functional movement can be referred to as dynamic ultrasound; this is feasible and reliable with the use of a linear transducer, elastic belt, and foam block to secure consistent transducer placement. The lateral abdominal wall is commonly investigated using ultrasound due to the overlapping nature of the muscles. Surface electromyography (sEMG) can complement M-mode ultrasound imaging because it measures the electrical representation of muscle activation. There is minimal evidence using M-mode ultrasound and sEMG simultaneously during core exercise. Exercises that challenge the core musculature involve both isometric holds (e.g., side plank), as well as oscillatory extremity movements (e.g., dead bug). In this study, both instruments will be used simultaneously to measure core muscle function during exercise. Ultrasound measurements will be obtained using a linear transducer and ultrasound unit, and sEMG measurements will be acquired from a wireless sEMG system. To make comparisons between participants and exercises, normalization methods using static, exercise starting positions for both instruments will be used. An activation ratio will be used for ultrasound and calculated by dividing the contracted thickness (thickness during a time point of exercise) by the rested (starting position) thickness. Muscle thickness will be measured in centimeters from the superior inferior fascial border to inferior superior fascial border. These methods aim to offer an innovative and practical measurement of muscle function with M-mode ultrasound and sEMG during core endurance exercises.

This protocol uses motion mode ultrasound and surface electromyography simultaneously to measure muscle function of the core. Muscle thickness and activation of the local stabilizers (e.g., transverse abdominis, internal oblique) and global movers (e.g., external oblique) is achievable during specific time points of the side plank and dead bug exercises.

コア持久力運動中のモーションモード超音波と表面筋電図で得られる筋機能

Motion mode (M-mode) ultrasound allows researchers and clinicians to measure the change of muscle thickness across time. Muscle thickness can be measured ...