Noone G, Ang W T
Dept. of Applied Mathematics, University of Adelaide South Australia.
Australas Phys Eng Sci Med. 1996 Mar;19(1):26-30.
The continuous cantilever beam model of the human spine usually assumes that the beam tangent at the inferior end of the structure is exactly perpendicular to the surface in which it is built into. The model used in this paper allows for realistic imperfections in the beam so that a small non-zero rotation is allowed at its inferior end. Such a model is used to investigate the lateral deformation of the muscle-relaxed spine as it supports asymmetrical loads in the frontal plane. By comparing the model deformations with previously published results, it was easily seen how such imperfections can effect the solution quantitatively. This was found to be especially true when the model was used to estimate the gross flexural rigidity of the spine in the frontal plane. It could also explain why some spines are more prone to lateral curvature and instability than others. Considering the importance of such a parameter when used in the continuous model, an investigation into the true nature of the inferior model boundary condition could be warranted.
人体脊柱的连续悬臂梁模型通常假定结构下端的梁切线与嵌入的表面精确垂直。本文所使用的模型考虑了梁中实际存在的缺陷，从而允许其下端有一个小的非零旋转。这种模型用于研究肌肉放松状态下的脊柱在额面承受不对称载荷时的侧向变形。通过将模型变形与先前发表的结果进行比较，可以很容易地看出这些缺陷如何在定量方面影响解决方案。当使用该模型估计脊柱在额面的总抗弯刚度时，发现尤其如此。这也可以解释为什么有些脊柱比其他脊柱更容易出现侧弯和不稳定。考虑到在连续模型中使用这样一个参数的重要性，对下端模型边界条件的真实性质进行研究可能是必要的。
