高张力致运动性骨骼肌损伤机制的研究(Ⅰ)——下坡跑对骨骼肌纤维生物力学性质的影响

Mechanism Study of Muscle Injury from High Tension (Ⅰ)——The Biomechanical Effect of Training on Muscle Injury from Downhill running in Rats

采用间歇性下坡跑运动，连续观察力竭性运动后即刻、２４ ｈ、４８ ｈ 大鼠快慢骨骼肌超微结构和被动状态下的材料力学特性及其变化规律。实验结果发现，大鼠经过力竭性持续下坡跑运动后，被动状态下快肌股直肌和慢肌比目鱼肌的载荷变形曲线或应力应变曲线反映了典型生物材料的力学性质（包括弹性、粘滞性及塑性），具有很高的非线性，呈指数形式。快慢骨骼肌的材料力学性质有明显的差异：快肌股直肌的极限强度、弹性模量明显高于慢肌比目鱼肌（Ｐ＜ ０．０５）；慢肌的极限应变明显高于快肌（Ｐ＜ ０．０５）；断裂前的能量吸收快肌远远高于慢肌（Ｐ＜ ０．００１）。

In this experiment, we tested the biomechanical characteristics of rat's fast and slow skeletal injury from downhill running at different times. The result indicates that the mechanical properties of fast and slow skeletal muscle, including maximum tensile strength, maximum strain, elasticity and energy absorption, gradually stregthen with extended time (not more than 48 hours) after eccentric exercise induced injury. On the other hand, the maximum strain of slow muscle is higher than that of fast muscle.