The objective of this study was to determine force-based lumbar spine injury criteria due to vertical impact using Post Mortem Human Surrogate (PMHS) experiments. Mounted personnel in military vehicles sustain loads from the pelvis in combat events such as underbody blast loadings. Forty-three post mortem human subject thoracolumbar spinal columns were obtained, screened for pre-existing trauma, bone mineral densities (BMDs) were determined, pre-test radiological images were taken, fixed at the ends in polymethylmethacrylate, load cells were attached to the ends of the fixation, positioned on custom vertical accelerator device based on a military-seating posture, and impacted at the base. Posttest images were obtained, and gross dissection was done to confirm injuries, classified into single and multilevel groups, groups A and B. Axial and resultant forces at the thoracolumbar (proximal) and lumbosacral (distal) joints were used as response variables to develop lumbar spine injury risk curves using parametric survival analysis. The Brier score metric was used to rank the variables. Age, BMD, column length, and vertebral body and intervertebral disc areas were used as covariates. The optimal metric describing the underlying response to injury was the distal resultant force for group A and proximal axial force for group B specimens. Force-BMD for group A and force-body area for group B were the best combinations. The IRCs with ±95% confidence intervals and quality of risk curves are given in the paper, and they serve as lumbar spine injury criteria. The present human cadaver Injury Risk Curves (IRCs) can be used to conduct matched pair tests to obtain dummy-based injury assessment risk curves/values to predict injury. The present IRCs can be used in human body finite element models. The relationship between covariates and primary forces presented in this study contribute to a better understanding of the role of demographic, geometric, and material factors to impact acceleration loading.

本研究的目的是使用尸检人类代孕 (PMHS) 实验确定垂直冲击导致的基于力的腰椎损伤标准。军用车辆中的安装人员在战斗事件中承受来自骨盆的载荷，例如底部爆炸载荷。获得 43 个死后人类受试者胸腰椎脊柱，筛查预先存在的创伤，测定骨矿物质密度 (BMD)，拍摄预测试放射图像，在末端固定在聚甲基丙烯酸甲酯中，将测力传感器连接到固定装置的末端，放置在基于军用坐姿的定制垂直加速器装置上，并在底部受到冲击。获得后测图像，并进行大体解剖以确认损伤，分为单级和多级组，A组和B组。胸腰椎（近端）和腰骶（远端）关节处的轴向力和合力被用作响应变量，使用参数生存分析来绘制腰椎损伤风险曲线。Brier 评分指标用于对变量进行排名。年龄、BMD、柱长、椎体和椎间盘面积被用作协变量。描述对损伤的潜在反应的最佳度量是 A 组样本的远端合力和 B 组样本的近端轴向力。A组的Force-BMD和B组的Force-BMD是最好的组合。论文中给出了具有 ±95% 置信区间和风险曲线质量的 IRC，它们作为腰椎损伤标准。目前的人体尸体损伤风险曲线（IRC）可用于进行配对测试以获得基于假人的损伤评估风险曲线/值来预测损伤。目前的 IRC 可用于人体有限元模型。本研究中提出的协变量和主要力之间的关系有助于更好地理解人口、几何和材料因素对影响加速度载荷的作用。