Shirazi-Adl A
Department of Mechanical Engineering, Ecole Polytechnique de Montréal, Quebec, Canada.
Spine (Phila Pa 1976). 1991 May;16(5):533-41. doi: 10.1097/00007632-199105000-00009.
In this study, the contact loads and regions on facets of a lumbar motion segment are quantitatively determined. The analysis accounts for both material and geometric nonlinearities and treats the facet articulation as a frictionless, nonlinear, moving contact problem. The loadings consist of axial torque and lateral bending acting alone or in combination with axial compression force. Complex loadings simulating symmetric and nonsymmetric liftings are also considered. Under identical magnitude of rotation, axial torque generates the largest contact forces, followed by extension, flexion, and lateral bending. Contact forces under loads simulating heavy symmetric lifting are as, or even larger than, those under large extension and axial torque loadings. The presence of axial and lateral rotations during forward flexion significantly increases the loads transmitted through the compression facet. The tension facet, in this case, became nearly unloaded. The large loads on the facets, predicted especially under nonsymmetric, combined flexion loadings, are likely to play a role in the observed disorders of the facet joints. Under various loadings, the transfer of forces from one facet to the adjacent one occurs through three distinct areas, namely, extension-type, flexion-type, and torsion-type contact areas. The relative magnitude of different components of the transmitted forces are also predicted to vary considerably, depending on these regions of contact.
在本研究中，定量测定了腰椎运动节段小关节面的接触载荷和接触区域。该分析考虑了材料和几何非线性，并将小关节连接视为无摩擦、非线性的移动接触问题。载荷包括单独作用或与轴向压缩力联合作用的轴向扭矩和侧弯。还考虑了模拟对称和非对称抬举的复杂载荷。在相同的旋转幅度下，轴向扭矩产生的接触力最大，其次是后伸、前屈和侧弯。模拟重度对称抬举时的接触力与大后伸和轴向扭矩载荷下的接触力相当，甚至更大。前屈时轴向和侧向旋转的存在显著增加了通过压缩小关节传递的载荷。在这种情况下，张力小关节几乎卸载。尤其是在非对称、联合前屈载荷下预测的小关节上的大载荷，可能在观察到的小关节紊乱中起作用。在各种载荷下，力从一个小关节传递到相邻小关节通过三个不同的区域，即后伸型、前屈型和扭转型接触区域。根据这些接触区域，传递力的不同分量的相对大小预计也会有很大差异。
