骨骼肌急性拉伤后牵张训练对其材料力学性能影响的实验研究

Effect of Stretching Training after Skeletal Muscle Injury on Muscular Material Mechanical Properties

目的:探讨牵张训练对骨骼肌急性拉伤后恢复期材料力学性能影响的规律。方法:92只SD大鼠为实验对象,选取10只为空白对照组,其余82只在同等条件下对其小腿三头肌实施急性拉伤后,随机分为实验对照组、牵张组和跑动组。于不同恢复期取腓肠肌进行拉伸测试,获取试样的拉伸极限张力-时间曲线,计算其应力、应变及弹性模量。结果:(1)极限应力:伤后第10天,牵张组和跑动组小腿三头肌的极限应力明显高于实验对照组(P <0 . 0 5 ) ;伤后第17天,牵张组小腿三头肌的极限应力恢复值最高(PPT -EC<0 . 0 5 )。(2 )极限应变:肌肉伤后第30天实验对照组小腿三头肌极限应变仅为正常肌肉的85 93% (P <0 . 0 1) ;伤后第10天牵张组肌肉极限应变为正常肌肉的98 19% ,第17天则明显高于正常肌肉(P <0 .0 1) ;跑动组伤后第10天也明显恢复(P <0 .0 1)。(3)杨氏模量:牵张对肌肉的模量的影响较自然修复及跑动训练均更明显。结论:急性拉伤肌肉抗拉性能基本恢复约需3周,应变恢复相对较慢。牵张对肌肉伤后的材料力学性能有积极的影响,但以影响应变性能和优化模量为主。肌肉急性拉伤后进行适量的跑动对肌肉的材料力学性能有积极作用,大强度跑动致重复性损伤的可能性加大。

Objective The purpose of this experiment was to study the effect of stretching training after skeletal muscle injury on muscular material mechanical properties. Methods 92 SD rats were served as the subjects. Ten of them were randomly separated from the others, and formed a blank control group. The rest, under the same condition, were acutely strained in their triceps surae muscles, and then further divided into naturally recovering group, stretching group, and running group. Gastrocnemius tension was tested at different rehabilitating time points for getting a force - time curve, from which following parameters （ stress, strain and elastic modulus） were derived. Results （1） Stress： Strecthing group and running group were better than naturally recovering group in terms of the maximal muscular stress on day 10. （2） Strain： only 85.93% of normal muscles on day 30 could be found in the naturally recovering group, while 98.19% of normal muscle on day 10 in the stretching group could be found, and similar finding also appeared in the running group. （3） Elastic modulus： The effect of stretching training on the muscular elastic modulus was more significant than naturally recovering and running. Conclusion After a acute muscle injury, the natural recovery process of skeletal muscles and the recovery of muscular stretch - bearing intensity usually took about 3 weeks, whereas the recovery of strain was rather slow. The stretching training facilitated the recovery of material mechanical properties through affecting mainly the muscular strain properties. Proper running training could also help the recovery of muscular material mechanical properties; nevertheless, over- load running could cause negative effect.