人体胫骨静力与冲击轴向载荷的生物力学特征

Biomechanical characteristics of static and impact axial loadings on human tibia

摘要:

［目的］ 探讨人体胫骨在静力载荷与冲击载荷作用下发生胫骨骨折的区别。［方法］ 20 个新鲜人体胫骨标本，随机分为两组，每组 10 个，左侧和右侧各 5 个，分别施加静力轴向载荷与动态冲击装置轴向载荷，测量其力学参数。［结果］静力学对照组 10 个标本的测试表明左侧胫骨的屈服载荷、屈服位移、极限载荷、极限位移均显著大于右侧（P<0.05）。动力冲击组 10 个标本在冲击速度为 2.5 m/s，冲击高度 32 cm，落锤重量 40 kg 的冲击下测试结果表明，左右两侧胫骨标本在动态冲击试验的加速度、冲击极限载荷、动态变形和载荷作用时间脉宽的差异均无统计学意义 （P>0.05）。两种加载试验相比较，动态冲击力作用下的胫骨极限载荷显著大于静态极限载荷 （P<0.05），动态冲击力作用下的胫骨动态形变大于静态极限位移 （P<0.05）。 ［结论］与静态轴向载荷相比，胫骨标本在动态冲击载荷状态下的极限载荷和极限位移均显著增加。

Abstract:

[Objective] To explore the biomechanical difference of human tibial fracture under static loading and impact loading. [Methods] Twenty fresh human tibia specimens were randomly divided into two groups, with 10 tibia in each group, 5 of the left side and 5 of the right side. Static axial loading and dynamic impact axial loading were applied respectively to measure the mechanical parameters. [Results] As result of static test, the yield load, yield displacement, ultimate load and ultimate displacement of the left tibia were significant- ly higher than those of the right tibia (P＜0.05) . However, in the dynamic impact group, 10 specimens were tested at impact velocity of 2.5 m/s, impact height of 32 cm, and drop weight of 40 kg, and the results showed that there were no significant differences in acceleration, im- pacting extreme load, dynamic deformation and load time pulse width between the left and right tibia specimens in dynamic impact test (P＞ 0.05) . In term of comparison of two loading state, the dynamic impacting loading had significantly greater ultimate load than the static load- ing (P＜0.05) , similarly, the dynamic impacting loading got significantly greater displacement than the static loading (P＜0.05) . [Conclusion] Compared with the static axial loading, the dynamic impact loading has significantly greater ultimate load and ultimate displacement of tibia specimens.