Considerations when loading spinal finite element models with predicted muscle forces from inverse static analyses.
Considerations when loading spinal finite element models with predicted muscle forces from inverse static analyses.
复制标题
DOI：
10.1016/j.jbiomech.2013.03.003
复制
发表时间：
2013-04
影响因子：
2.4
通讯作者：
R. Zhu;T. Zander;M. Dreischarf;G. Duda;A. Rohlmann;H. Schmidt
中科院分区：
文献类型：
--
作者：
R. Zhu;T. Zander;M. Dreischarf;G. Duda;A. Rohlmann;H. Schmidt
由于缺乏肌肉生理载荷的数据，大多数简化载荷被用于脊柱的生物力学有限元（FE）研究。逆静态（IS）模型允许预测预定义姿势的肌肉力量。两种机械方法的组合- FE和IS -似乎允许更真实的建模。然而，目前尚不清楚当为具有刚性椎骨和固定旋转中心的模型计算的肌肉力（如通常在IS模型中发现的）应用于具有弹性椎骨和椎间盘的FE模型时，预期会出现什么样的偏差。本研究的目的是确定这些分歧的影响。在IS模型中估计20°屈曲和10°伸展的肌肉力，并转移到FE模型中。使用FE模型的实际椎间旋转（IVR）偏差和IS模型的目标IVR，量化骨结构弹性（刚性与弹性）的影响和旋转中心的定义（固定与非固定）。对于伸展，椎骨的弹性对IVR的影响很小，而旋转中心不固定使IVR偏差平均每节段增加0.5°。对于屈曲，两个参数的组合使每个节段的IVR偏差平均增加1°。当使用IS分析中预测的肌肉力加载FE模型时，必须考虑IS模型中的主要限制-节段刚度和固定旋转中心。
Mostly simplified loads were used in biomechanical finite element (FE) studies of the spine because of a lack of data on muscular physiological loading. Inverse static (IS) models allow the prediction of muscle forces for predefined postures. A combination of both mechanical approaches – FE and IS – appears to allow a more realistic modeling. However, it is unknown what deviations are to be expected when muscle forces calculated for models with rigid vertebrae and fixed centers of rotation, as generally found in IS models, are applied to a FE model with elastic vertebrae and discs. The aim of this study was to determine the effects of these disagreements. Muscle forces were estimated for 20° flexion and 10° extension in an IS model and transferred to a FE model. The effects of the elasticity of bony structures (rigid vs. elastic) and the definition of the center of rotation (fixed vs. non-fixed) were quantified using the deviation of actual intervertebral rotation (IVR) of the FE model and the targeted IVR from the IS model. For extension, the elasticity of the vertebrae had only a minor effect on IVRs, whereas a non-fixed center of rotation increased the IVR deviation on average by 0.5° per segment. For flexion, a combination of the two parameters increased IVR deviation on average by 1° per segment. When loading FE models with predicted muscle forces from IS analyses, the main limitations in the IS model – rigidity of the segments and the fixed centers of rotation – must be considered.