Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
J Biomech. 2021 Jun 9;122:110479. doi: 10.1016/j.jbiomech.2021.110479. Epub 2021 Apr 25.
To date, no in vitro studies have been conducted to explore lumbar soft tissue injury potential and altered mechanical properties from exposure to impact forces. After a motor vehicle collision (MVC), the cause of reported acute onset low back pain is difficult to associate with potential soft tissue strain injury sites including the facet joint and innervated facet joint capsule ligament (FJC). Thus, the purpose of this investigation was to quantify intervertebral anterior-posterior (AP) translation and facet joint capsule strain under varying postures and impact severities. Seventy-two porcine spinal units were exposed to three levels of impact severity (4 g, 8 g, 11 g), and posture (Neutral, Flexion, Extension). Impacts were applied using a custom-built impact track that replicated parameters experienced in low to moderate speed rear-end MVCs. Flexion-extension and anterior-posterior shear neutral zone testing were completed prior to impact. AP intervertebral translation and the strain tensor of the facet capsule ligament were measured during impacts. A significant main effect of collision severity was observed for peak AP intervertebral translation (4 g-2.8 ±0.53 mm; 8 g-6.4 ±2.9 mm; 11 g-8.3 ±0.45 mm) and peak FJC shear strain (2.37% strain change from 4 g to 11 g impact severity). Despite observed main effects of impact severity, no influence of posture was observed. This lack of influence of posture and small FJC strain magnitudes suggest that the FJC does not appear to undergo injurious or permanent mechanical changes in response to low-to-moderate MVC impact scenarios.
迄今为止，尚无体外研究探索过因暴露于撞击力而导致的腰椎软组织损伤潜力和机械特性改变。在发生机动车碰撞（MVC）后，报告的急性腰痛发作的原因很难与潜在的软组织应变损伤部位相关联，包括关节突关节和受神经支配的关节突关节囊韧带（FJC）。因此，本研究的目的是量化在不同姿势和撞击严重程度下的椎间前后（AP）平移和关节突关节囊应变。72 个猪脊柱单位分别暴露于三种撞击严重程度（4 g、8 g、11 g）和三种姿势（中立位、前屈位、后伸位）。使用定制的撞击轨道对脊柱施加撞击，该轨道复制了低到中速追尾 MVC 中经历的参数。在撞击前完成了屈伸和前后剪切中立区测试。在撞击过程中测量了 AP 椎间平移和关节突关节囊韧带的应变张量。撞击严重程度的峰值 AP 椎间平移（4 g-2.8 ±0.53 mm；8 g-6.4 ±2.9 mm；11 g-8.3 ±0.45 mm）和峰值 FJC 剪切应变（4 g 至 11 g 撞击严重程度的应变变化 2.37%）有显著的主效应。尽管观察到撞击严重程度的主要影响，但姿势没有影响。这种姿势的影响较小以及关节突关节囊应变幅度较小表明，在低到中度 MVC 撞击情况下，关节突关节似乎不会因机械损伤或永久性机械变化而发生改变。
