Cholewicki J, Crisco J J, Oxland T R, Yamamoto I, Panjabi M M
Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA.
Spine (Phila Pa 1976). 1996 Nov 1;21(21):2421-8. doi: 10.1097/00007632-199611010-00003.
A biomechanical lumbar spine model was constructed to simulate three-dimensional spinal kinematics under the application of pure moments. Parametric analysis of the model allowed for the estimation of how much of the coupled motions could be predicted by the lumbar lordosis and the intrinsic mechanical properties of the spine.
To evaluate the relative effects of lordosis and intrinsic mechanical spine properties on the magnitude and direction of coupled rotations.
Clinical evidence suggests that abnormal coupled motion in the lumbar spine may be an indicator of low back disorders.
The biomechanical lumbar spine model consisted of five vertebrae separated by intervertebral joints that provided three rotational degrees of freedom. In vitro experimental data, obtained from nine fresh-frozen (L1-S1) cadaveric specimens, were used to establish the mechanical properties of the intervertebral joints. Two different submodels were considered in simulating the three-dimensional intervertebral rotations in response to the applied moments. In the first, it was assumed that the coupled motions were generated solely as a result of the vertebral orientation caused by lordosis. In the second, additional intrinsic motion coupling was assumed.
Intervertebral coupling was partially predicted by lumbar lordosis; however, the inclusion of intrinsic mechanical coupling dramatically improved the simulation of the intervertebral rotations (root mean square error < 1 degree). Comparison of the results from the two models demonstrated that the lumbar lordosis and intrinsic mechanical properties of the spine had about an equal effect in predicting the coupling between axial rotation and lateral bending. In contrast, coupled flexion, associated with lateral bending, was almost fully accounted for by the presence of lumbar lordosis.
The lumbar lordosis and intrinsic mechanical properties of the spine were equally important in predicting the magnitude and direction of the coupled rotations.
构建了一个生物力学腰椎模型，以模拟在纯力矩作用下的三维脊柱运动学。对该模型进行参数分析，可以估计腰椎前凸和脊柱固有力学特性能够预测多少耦合运动。
评估前凸和脊柱固有力学特性对耦合旋转的大小和方向的相对影响。
临床证据表明，腰椎异常的耦合运动可能是下背部疾病的一个指标。
生物力学腰椎模型由五个椎体组成，椎体之间由提供三个旋转自由度的椎间关节分隔。从九个新鲜冷冻（L1-S1）尸体标本中获得的体外实验数据，用于确定椎间关节的力学特性。在模拟响应所施加力矩的三维椎间旋转时，考虑了两种不同的子模型。在第一个模型中，假设耦合运动完全是由前凸引起的椎体方向产生的。在第二个模型中，假设存在额外的固有运动耦合。
椎间耦合部分由腰椎前凸预测；然而，纳入固有力学耦合显著改善了椎间旋转的模拟（均方根误差<1度）。两个模型结果的比较表明，腰椎前凸和脊柱固有力学特性在预测轴向旋转和侧方弯曲之间的耦合方面具有大致相同的效果。相比之下，与侧方弯曲相关的耦合屈曲几乎完全由腰椎前凸的存在来解释。
腰椎前凸和脊柱固有力学特性在预测耦合旋转的大小和方向方面同样重要。
