BACKGROUND:Several finite element (FE) models have been developed to study the effects of vibration on human lumbar spine. However, the authors know of no published results so far that have proposed computed tomography-based FE models of whole lumbar spine including the pelvis to conduct dynamic analysis. OBJECTIVE:To create and validate a three-dimensional ligamentous FE model of the human lower thorax to pelvis spinal segment (T12–Pelvis) and provide a detailed simulation environment to investigate the dynamic characteristics of the lumbar spine under whole body vibration (WBV). METHODS:The T12–Pelvis model was generated based on volume reconstruction from computed tomography scans and validated against the published experimental data. FE modal analysis was implemented to predict dynamic characteristics associated with the first-order vertical resonant frequency and vibration mode of the model with upper body mass of 40 kg under WBV. RESULTS:It was found that the current FE model was validated and corresponded closely with the published data. The obtained results from the modal analysis indicated that the first-order vertical resonant frequency of the T12–Pelvis model was 6.702 Hz, and the lumbar spine mainly performed vertical motion with a small anteroposterior motion. It was also found that shifting the upper body mass centroid onwards or rearwards from the normal upright sitting posture reduced the vertical resonant frequency. CONCLUSIONS:These findings may be helpful to better understand vibration response of the human spine, and provide important information to minimize injury and discomfort for these WBV-exposed occupational groups.

中文翻译：

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人体下胸至骨盆脊柱节段的有限元模型：验证和模态分析

背景：已经开发了几种有限元 (FE) 模型来研究振动对人体腰椎的影响。然而，作者知道到目前为止还没有发表的结果提出了基于计算机断层扫描的整个腰椎（包括骨盆）的有限元模型来进行动态分析。目的：建立并验证人体下胸至骨盆脊柱节段（T12-Pelvis）的三维韧带有限元模型，为研究全身振动（WBV）下腰椎的动态特性提供详细的仿真环境。方法：T12-骨盆模型是根据计算机断层扫描的体积重建生成的，并根据已发表的实验数据进行验证。实施有限元模态分析以预测与上体质量为 40 kg 的模型在 WBV 下的一阶垂直共振频率和振动模式相关的动态特性。结果：发现当前的有限元模型经过验证并与公布的数据密切对应。模态分析结果表明，T12-骨盆模型的一阶垂直共振频率为6.702Hz，腰椎以垂直运动为主，前后运动较小。还发现从正常的直立坐姿向前或向后移动上半身重心会降低垂直共振频率。结论：这些发现可能有助于更好地了解人体脊柱的振动响应，