摘要
目的:应用三维有限元分析法认识腰椎小关节的力学分布特点。方法:①实验于1999-10/2001-06在福州大学力学工程系光弹实验室完成。取新鲜尸体10具,6男4女,年龄45～65岁。尸体来源:福建中医学院解剖教研室。②通过对尸体腰段脊柱表面各节点的三维坐标值测量,运用超级空间有限元电算程序(SUPER-SAPV)将腰段脊柱按空间有限离散的原则划分为496个单元,1002个节点。并在计算机上建立三维空间坐标系,模拟完整脊柱腰段力学模型。运用横截面积肌力计算法,测量尸体腰椎周围肌肉:腰大肌、腰方肌、竖脊肌、腹内外斜肌、腹横肌的解剖横断面积,及其与腰段脊柱纵轴的中心距数值,求得力矩值。再根据力矩等价换算公式得出加载于模型体表各点的肌力值。通过对本模型重力及肌力的加载,使其更接近于正常人体腰段力学状态。运用腰椎周围不同肌肉对腰段脊柱作用力的变化,模拟正常活动范围内脊柱腰段前屈、后伸、右侧屈、右旋4种不同工况。分别计算相应载荷下脊柱腰段小关节的动态应力分布状况和应变值。结果:腰段小关节在正常生理活动范围内,各节段小关节前屈、后伸位、右侧屈(左侧)、右旋位(左侧)应力值由L5～S1至L1～2分别从122.83,282.51,92.22,118.84MPa减少至32.58,64.63,4.29,2.39MPa。小关节在后伸位时应力值最大,其次是前屈位及旋转,侧屈位应力值最小。结论:前屈及后伸位出现明显的应力集中,其中后伸位最为明显。
AIM： To investigate the mechanics distribution of apophysial joints in lumbar spine by three-dimensional （3-D） finite element analysis.
METHODS： （1）The experiment was carried out in the Photoelastic Laboratory of Fuzhou University between October 1999 and June 2001. Ten fresh corpse aged 45-65 years were adopted from the Department of Anatomy in Fujian College of Traditional Chinese Medicine, including 6 males and 4 females. （2）The surface nodes of 3-D lumbar spine in human corpse were measured and the lumbar spine were artificially divided into 496 units （including 1 002 nodes） according to the finite division program of 3-D coordinate system （SUPER-SAP V） of lumbar spine model. We also measured the force of muscular around the lumbar spine by cross-sectional area caiculation, such as psoas major muscle, quadratus lumborum, erector spinae, internal abdominal oblique, rectus abdominis and transversus abdominis. The center distance of longitudinal axis in lumbar spine was also calculated for the moment of force. Then the force of muscle was achieved by the equivalence conversion equation, which was downloaded in the model. Both the gravity and muscular force were loaded in the model so as to be close to the normal mechanic condition of human lumbar vertebra. The condition of stress on lumbar spine was changed by the force of different muscles under several normal postures such as forward bending, afterward stretch, one-side bending and rotation. Then the changing stress and strain of the model under different postures were calculated.
RESULTS： The stress values of vertebral apophysial joints among L5-S1-L1-2 decreased from 122.83, 282.51, 92.22, 118.84 MPa to 32.58, 64.63, 4.29, 2.39 MPa in anteflexion, postexion, one-side bending and rotation, respectivey. The stress of apophysial joints was the highest in the postexion, then anteflexion and one-side rotation, the lowest in one-side bending.
CONCLUSION： The concentration phenomenon of the stress prominently appears in anteflexion and postexion, in which the value of postexion position is the largest.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2007年第9期1671-1674,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
基金
福建省科技厅资助(9867)~~
