独立神経駆動とイソメトリックな膝の屈折時のハンストリング筋肉の独特の放電特性
Chrysostomos Sahinis1, Ioannis G Amiridis2, Dario Farina3
1Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Agios Ioannis, 62110, Serres, Greece. sachinic@phed-sr.auth.gr.
European journal of applied physiology
|September 4, 2025
まとめ
半筋 (ST) と筋 (BF) の運動単位 (MU) の放出パターンは,膝の角度によって異なります. これらの異なる神経駆動は 筋肉特有のトレーニング戦略の必要性を強調しています
科学分野:
- 神経筋肉の生理学
- バイオメカニクス
- 運動科学
背景:
- モーターユニット (MU) コントロールを理解することは,筋肉の機能とトレーニングを最適化するために不可欠です.
- 半筋 (ST) と筋 (BF) の筋肉は,膝の屈折に重要な役割を果たしますが,それらの異なる神経制御メカニズムは完全に解明されていません.
- 膝関節の角度によって影響される筋肉の長さは,筋肉の力産生と運動ユニットの活動に大きく影響します.
研究 の 目的:
- 半筋 (ST) と筋 (BF) の運動単位 (MUs) の放電特性を調査し比較する.
- 異なる筋肉の長さを表す,異なる膝関節の角度 (0°,45°,90°) で,これらのMU放出パターンがどのように変化するかを調べる.
- イソメトリック収縮時にSTとBFの神経駆動と調整を評価する.
主な方法:
- 15人の健康な男性は,膝関節の3つの角度で,最大自発的収縮 (MVC) の10~60%でイソメトリックな膝関節収縮を行いました.
- 高密度電気ミオグラフィ (EMG) を用いて,筋肉の活動を記録し,信号を分解して,MUの放電時間を特定しました.
- 平均放出率 (MDR) と変動率 (CoV ISI,fCSTのSD) を含む主要なMU放出特性を計算した. 神経駆動の調整は,フィルターされた累積スパイクトレイン (fCST) のクロス相関によって評価された.
主要な成果:
- 最大の自発的な収縮力 (MVC) は,最も長い筋肉の長さ (0°の膝の角度) で最大であり,トルク安定性は中間長さ (45°) で最悪であった.
- バイセプス・フェモリス (BF) はより高い平均放出率 (MDR) とより高い神経駆動の変動率 (fCSTのSD) を示し,半骨 (ST) はより高い放出率の変動率 (CoV ISI) を示した.
- STとBFの神経駆動の間の低い交差関係は,独立した筋肉制御を示唆した. STのニューラルドライブの変動性は,BFよりもトルク安定性に強く相関していた.
結論:
- 運動ユニット放電の特徴と神経駆動は,半筋 (ST) と筋 (BF) の間で明確なパターンを表します.
- これらの違いは,膝関節の角度によって変化し,異なる長さの各筋肉のユニークな神経制御戦略を示しています.
- これらの発見は,膝の屈曲機能の強化のための筋肉特有の適応とトレーニングプロトコルの重要性を強調しています.
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