不同强度的跑跳运动对老龄大鼠股骨生物力学特性影响的动态实验研究

目的：探讨不同运动时间、不同强度的跑跳运动对衰退骨组织的生物力学特性的影响作用，为骨质疏松患者的临床康复治疗提供参考。方法： 105只SD雄性大鼠，随机分成1个对照组（组0）和4个实验组（每天运动时间10min的为实验组1，20min的为实验组2，30min的为实验组3，40min的为实验组4），每实验组又分为运动时间为1、3、6、9、12周不同的5类，通过电刺激驱使大鼠运动。运动结束立即处死，通过电子式材料试验机测量生物力学指标。结果：实验组1在6个股骨生物力学指标的变化上基本一致，处于缓慢增长趋势，与对照组比较差异无显著性；实验组2，波动较大，基本处于先增后减，然后有快速增长的变化趋势，与对照组比较差异有显著性。实验组3和实验组4的变化基本相一致，都处于下降趋势，而且实验组4的下降更为明显，与对照组比较差异有显著性。结论：长时间适宜强度的运动能显著改善老龄鼠股骨生物力学性能，高强度长时间的运动则降低衰退骨组织的生物力学性能，低强度的运动无明显影响。长时间适宜强度的运动对延缓骨细胞衰老和骨组织的功能衰减具有积极意义。

Dynamic study on effects of exercises intensity on biomechanical characteristics in ageing bone

Objective: To determine the effects of different exercises intensities and exercises times on the structure and function of recessional bone tissue. Method: One hundred and five male SD rats were randomly divided into 5 groups: one control group and four experimental groups: experimental group 1(10min exercises every day); experimental group 2(20 min exercises every day); experimental group 3(30min exercises every day); experimental group 4(40 min exercises every day); in addition, every experimental group was subdivided into 5 different subgroups according to the exercises programs(1 week,3 weeks,6 weeks,9 weeks,12 weeks). All rats were sacrificed immediately when their exercises programs were finished. Biomechanical indexes were measured with electronic material test apparatus. Result: Six biomechanical indexes of femurs in experimental group 1 elevated slowly, resembling that in control group; in experimental group 2 the indexes fluctuated in a large extent, at first elevating then reducing, after that appeared a tend of rapid elevating, which were significantly different from those in control group; the changes in experimental group 3 and group 4 were mainly identical, showing a declining tend, especially in experimental group 4,which had great differences from control group. Conclusion: Exercises intensity and exercises time could greatly influence on the structure and function of aging bone tissue. Moderate intensity and long time exercises could activly influence on the retard of cells aging and function degradation of bone tissues. improve the metabolism, structure, function and biomechanical characteristics. While high-intensity and long time exercises could lower the biomechanical characteristics of ageing bone tissue; low-intensity exercise had no obvious effects on the metabolism, structure and function of ageing bone tissue.