School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China.
Spine (Phila Pa 1976). 2018 Feb 1;43(3):E143-E153. doi: 10.1097/BRS.0000000000002247.
A finite element study of dynamic response of the lumbar spine to whole-body vibration.
The aim of this study was to develop and validate a finite element model for exploring the impact of whole-body vibration on the entire lumbar spine with a compressive follower preload applied.
Several finite element studies have investigated the biodynamic characteristics of the human lumbar spine when exposed to whole-body vibration. However, very limited studies have been performed to quantitatively describe dynamic response in time domain of the entire lumbar spine to vibration loading under a compressive follower preload.
A three-dimensional nonlinear finite element model of the human lumbar spine (L1-sacrum) subjected to the compressive follower preload was created. Transient dynamic analysis was conducted on the model to compute the spinal response to a sinusoidal vertical vibration load of ±40 N under a 400 N preload. The obtained dynamic response results at all spinal levels were collected and plotted as a function of time. As a comparison, the corresponding results for vertical static loads (-40 and 40 N) under the preload (400 N) were also computed.
Plots of the dynamic response at all levels showed a cyclic response with time, and their vibration amplitudes (peak-to-bottom variations) were markedly higher than the corresponding changing amplitudes of static load cases. The increasing effect of the vibration load reached 314.5%, 263.2%, 242.4%, and 232.7%, respectively, in axial displacement of vertebral center, disc bulge, intradiscal pressure, and annulus stress (von-Mises stress). In addition, increasing the compressive follower preload led to an increase in the dynamic response and a decrease in their vibration amplitudes.
This study may be useful to help quantify the effect of cyclic loading on the entire lumbar spine under physiologic compressive loading, and better understand vibration characteristics of the spine.
全身振动对腰椎动态响应的有限元研究。
本研究旨在开发和验证一种有限元模型，用于探索在施加压缩跟随预载的情况下，全身振动对整个腰椎的影响。
已有几项有限元研究调查了人体腰椎在暴露于全身振动时的生物动力特性。然而，很少有研究定量描述在压缩跟随预载下，整个腰椎在时域内对振动载荷的动态响应。
创建了一个受压缩跟随预载作用的人体腰椎（L1-骶骨）的三维非线性有限元模型。对模型进行瞬态动力学分析，以计算在 400N 预载下，正弦垂直振动载荷为±40N 时的脊柱响应。收集所有脊柱水平的获得的动态响应结果并绘制为时间函数。作为比较，还计算了在预载（400N）下垂直静态载荷（-40 和 40N）的相应结果。
所有水平的动态响应图显示出随时间的周期性响应，其振动幅度（峰值到谷底的变化）明显高于静态载荷情况的相应变化幅度。振动载荷的增加效应分别在椎体中心轴向位移、椎间盘膨出、椎间盘内压和环向应力（von-Mises 应力）中达到 314.5%、263.2%、242.4%和 232.7%。此外，增加压缩跟随预载会导致动态响应增加，而振动幅度减小。
本研究可能有助于量化在生理压缩载荷下循环载荷对整个腰椎的影响，并更好地理解脊柱的振动特性。
5 级。
