A novel method of studying fascicle architecture in relaxed and contracted muscles.
A novel method of studying fascicle architecture in relaxed and contracted muscles.
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DOI：
10.1016/j.jbiomech.2010.07.031
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发表时间：
2010-11
影响因子：
2.4
通讯作者：
H. Stark;N. Schilling
中科院分区：
文献类型：
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作者：
H. Stark;N. Schilling
肌肉的结构，如束羽角或长度等几何变量描述，在其功能中起着至关重要的作用。通常，单个参数被用来估计力矢量或延长率，从而假设它们正确地代表了结构，并且在收缩期间是恒定的。为了更详细地描述肌肉结构并比较放松和收缩状态，我们开发并验证了一种新方法。分枝将实验大鼠比目鱼肌在放松和等长收缩状态下进行休克冷冻，从组织学切片中进行三维重建，并分析了肌束长度、曲率和羽状角以及腱膜的形状。在体积分布和形状的腱膜以及局部不同的变化，在束架构的显着差异进行了观察。虽然平均pennation角由于收缩仅增加2°，但观察到高达4°的局部变化。束曲在远端增加，但在近端部分保持不变。我们的方法可能有助于识别肌肉内的功能亚基，即，具有同质建筑属性的区域。我们的研究结果进行了讨论，关于输入参数至关重要的现实的肌肉建模和挑战的最大等长力的估计是基于生理横截面积或希尔模型。
A muscle’s architecture, described by geometric variables such as fascicle pennation angles or lengths, plays a crucial role in its functionality. Usually, single parameters are used to estimate force vectors or lengthening rates, thereby assuming that they represent the architecture properly and are constant during contraction. To describe muscle architecture in more detail and compare relaxed and contracted states, we developed and validated a new approach. The m. soleus of the laboratory rat was shock-frozen while relaxed and under isometric contraction, reconstructed three-dimensionally from histological sections, and fascicle lengths, curvatures and pennation angles, as well as the shape of the aponeuroses were analysed. Remarkable differences in volume distribution and the shapes of the aponeuroses as well as locally varying changes in the fascicle architecture were observed. While the mean pennation angle increased by only 2° due to contraction, local changes of up to 4° were observed. Fascicle curvature increased in the distal but remained unchanged in the proximal parts. Our approach may help to identify functional subunits within the muscle, i.e., regions with homogeneous architectural properties. Our results are discussed regarding the input parameters essential for realistic muscle modelling and challenge maximum isometric force estimations that are based on the physiological cross-sectional area or the Hill-model.