目的 基于假人模型,研究水平负向加速度(-Gx)作用下不同靠背角与颈部损伤的关系。 方法 将假人模型面朝轨道方向,固定在加速度平台底座上,设置靠背角为 17°、22°、30° 3 个实验组,每个实验组按照相同的加速度曲线分别进行 10 次重复试验,比较相同-Gx 条件下颈椎上、下部加速度差异,通过曲线拟合计算并比较颈部损伤指数(neck injury criteria,NIC)。 结果 颈椎上、下部在前后向、垂直向的加速度变化曲线形态一致,存在峰值差异;在前后向(X 轴),靠背角 22°实验组的加速度峰值稍高于 17°、30°靠背角实验组的加速度峰值;在垂直向(Z 轴),靠背角 22°实验组的加速度峰值低于 17°、30°靠背角实验组的加速度峰值;在前后向及垂直向,靠背角 22°实验组测得的 NICmax 较小,靠背角 30°实验组测得的 NICmax 次之,靠背角 17°实验组测得的 NICmax 较大。 结论 靠背角度与颈部损伤之间呈非线性关系。 本实验中在-Gx 作用下,靠背角为 22°时假人模型的颈部损伤较小。
Objective Based on the dummy model, to study the relationship between different backrest angles and neck injuries under the effect of horizontal negative acceleration (-Gx ). Methods The dummy model was fixed on the base of the acceleration platform facing the orbital direction, and the backrest angle was set at 17°, 22°, 30°, respectively. Each experimental group performed 10 repeated tests according to the same acceleration curve, differences between the upper and lower acceleration of the cervical spine under the same -Gx conditions were compared, and the neck injury criteria (NIC) was calculated and compared through curve fitting. Results The time-acceleration curves of the upper and lower cervical spine in the anteroposterior and vertical directions had the same shape with peak differences. In the anteroposterior direction (X-axis), the acceleration peak of the 22° backrest angle experimental group was slightly higher than that of 17° and 30° backrest angle experimental groups, but in the vertical direction (Z-axis), the acceleration peak of the 22° backrest experimental group was lower than that of 17° and 30° backrest angle experimental groups. In the anteroposterior and vertical directions, the NICmax measured by 22° backrest angle experimental group was relatively smaller, NICmax measured by 30°backrest angle experimental group was in the middle, and NICmax measured by 30° backrest angle experimental group was relatively larger. Conclusions There was a nonlinear relationship between the backrest angle and theneck injury. The neck injury of the dummy model with the backrest angle of 22° was smallest under the effect of -Gx in this experiment.