Muscle function during jumping in frogs .1. Sarcomere length change, EMG pattern, and jumping performance
Muscle function during jumping in frogs .1. Sarcomere length change, EMG pattern, and jumping performance
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DOI：
10.1152/ajpcell.1996.271.2.c563
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发表时间：
1996-08-01
影响因子：
5.5
通讯作者：
Rome, LC
中科院分区：
文献类型：
--
作者：
Lutz, GJ;Rome, LC
我们确定了跳跃过程中温度对肌肉功能的影响，以更好地了解青蛙肌肉系统是如何设计来产生高水平的机械动力的。测量了半膜肌（SM）（髋部伸肌）的最大跳跃性能和体内操作条件，并将其与随附论文[青蛙跳跃期间的肌肉功能]中分离的 SM 的机械特性相关联。二.肌肉的机械特性：对系统设计的影响。是。 J.生理学。 271（细胞生理学。40）：C571-C578，1996]。将温度从 25 摄氏度降低到 15 摄氏度会导致峰值机械发电量下降 1.75 倍，空中跳跃距离也成比例下降。在两种温度下，髋关节和膝关节的偏移几乎相同。因此，在两种温度下，肌节在相同范围内缩短（2.4至1.9μm），对应于肌丝重叠至少为最大重叠的90%。然而，在低温下，动作变得更慢。 15 摄氏度时，角速度降低了 1.2 至 1.4 倍，触地时间增加了 1.33 倍。15 摄氏度时，SM 的平均缩短速度仅比 25 摄氏度时低 1.2 倍。速度的低 Q(10) 与肌肉抵抗惯性负载缩短的预测结果一致。
We determined the influence of temperature on muscle function during jumping to better understand how the frog muscular system is designed to generate a high level of mechanical power. Maximal jumping performance and the in vivo operating conditions of the semimembranosus muscle (SM), a hip extensor, were measured and related to the mechanical properties of the isolated SM in the accompanying paper [Muscle function during jumping in frogs. II. Mechanical properties of muscle: implication for system design. Am. J. Physiol. 271 (Cell Physiol. 40): C571-C578, 1996]. Reducing temperature from 25 to 15 degrees C caused a 1.75-fold decline in peak mechanical power generation and a proportional decline in aerial jump distance. The hip and knee joint excursions were nearly the same at both temperatures. Accordingly, sarcomeres shortened over the same range (2.4 to 1.9 mu m) at both temperatures, corresponding to myofilament overlap at least 90% of maximal. At the low temperature, however, movements were made more slowly. Angular velocities were 1.2- to 1.4-fold lower, and ground contact time was increased by 1.33-fold at 15 degrees C. Average shortening velocity of the SM was only 1.2-fold lower at 15 degrees C than at 25 degrees C. The low Q(10) of velocity is in agreement with that predicted for muscles shortening against an inertial load.