模拟腰部推拿手法建立“腰-盆-髋”有限元模型

背景：对局部椎体或整个脊柱进行推拿手法的有限元分析具有一定的局限性。目的：通过建立“腰-盆-髋”有限元模型对腰部推拿手法进行相关生物力学分析。方法：利用螺旋CT 数据通过Mimics 10.01 建立具有高度几何相似性的腰椎、骨盆和股骨近端复合体骨骼的面模型，利用geomagic9精修模型，在hypermesh10.0中划分网格，添加椎间盘和主要韧带。并对有限元模型各部件进行材料属性赋值。利用有限元分析软件模拟腰椎推拿手法三工况加载，计算特征部位位移、最大应变及应力。结果与结论：有限元模型在三工况载荷下的特征部位应力、应变值基本能够反映“腰-盆-髋”特有的力学结构特性，模型的仿真性较好。在近似的几何外形下，据生物力学资料报道的材料赋值建模保证了有限元模型计算的正确性；模拟接近生理状况下的边界及载荷条件进行计算可以确保结果的准确性。

Construction of a three-dimensional finite element model of “lumber-pelvic-hip” to simulate lumbar massage technique

BACKGROUND: The finite element analysis of partial vertebral or entire vertebral massage technique has its limitation.OBJECTIVE:To build an infinite element model of “lumber-pelvic-hip” to research the biomechanical mechanism of lumbar massage.METHODS:Surface models of the lumbar, pelvis and proximal femur bone complex with high geometric similarity were constructed by Mimics 10.01 through importing subject-specific spiral CT data. Then, the models were modified though geomagic9 software, and solid modeling was converted from triangular based surface model by hypermesh10.0 software to add intervertebral disc and ligaments. According to the relevant literature on the finite element model, material properties were assigned for each component. Three loading conditions were used to simulate lumbar massage technique in finite element analysis software Abaqus6.5 software. Finally, the displacement, von-Misses stress and strains of specific location in the “lumber-pelvic-hip” infinite models were calculated by computer.RESULTS AND CONCLUSION:The displacement, von Misses stress and strains of specific location in the model under the three conditions could reflect the biomechanical characteristics of the lumber-pelvic-hip, implying the accuracy of the finite element model. Geometric similarity is essential for a finite element model, and subject-specific material assignment according to reported biomechanical data can ensure the accuracy of the model. Both loads and boundary conditions approximation to physiologically environment in the finite element models ensure the accuracy of results.