Lopez-Valdes Francisco J, Lau Anthony, Lamp John, Riley Patrick, Lessley David J, Damon Andrew, Kindig Matthew, Kent Richard, Balasubramanian Sriram, Seacrist Thomas, Maltese Matthew R, Arbogast Kristy B, Higuchi Kazuo, Tanji Hiro
University of Virginia ECIP- Universidad de Navarra.
Ann Adv Automot Med. 2010;54:61-78.
Quantifying the kinematics of the human spine during a frontal impact is a challenge due to the multi-degree-of-freedom structure of the vertebral column. This papers reports on a series of six frontal impacts sled tests performed on three Post Mortem Human Surrogates (PMHS). Each subject was exposed first to a low-speed, non-injurious frontal impact (9 km/h) and then to a high-speed one (40 km/h). Five additional tests were performed using the Hybrid III 50(th) percentile male ATD for comparison with the PMHS. A 3D motion capture system was used to record the 6-degree-of-freedom motion of body segments (head, T1, T8, L2, L4 and pelvis). The 3D trajectories of individual bony structures in the PMHS were determined using bone-mounted marker arrays, thus avoiding skin-attached markers and their potential measurements artifacts. The PMHS spines showed different behavior between low and high speed. While at low speed the head and upper spinal segments lagged the lower portion of the spine and pelvis in reaching their maximum forward displacement (time for maximum forward head excursion was 254.3±31.9 ms and 140.3±9 ms for the pelvis), these differences were minimal at high speed (127±2.6 ms for the head vs. 116.7±3.5 ms for the pelvis). The ATD did not exhibit this speed-dependant behavior. Furthermore, the ATD's forward displacements were consistently less than those exhibited by the PMHS, regardless of the speed. Neck loads at the atlanto-occipital joint were estimated for the PMHS using inverse dynamics techniques and compared to those measured in the ATD. It was found that the axial and shear forces and the flexion moment at the upper neck of the PMHS were higher than those measured in the ATD.
由于脊柱的多自由度结构，量化人体脊柱在正面撞击时的运动学是一项挑战。本文报告了在三个尸体人体模型（PMHS）上进行的一系列六次正面撞击雪橇试验。每个受试者首先受到低速、无损伤的正面撞击（9公里/小时），然后受到高速撞击（40公里/小时）。另外进行了五次试验，使用第50百分位的男性Hybrid III假人进行比较。使用三维运动捕捉系统记录身体各部分（头部、T1、T8、L2、L4和骨盆）的六自由度运动。通过安装在骨骼上的标记阵列确定PMHS中单个骨结构的三维轨迹，从而避免使用附着在皮肤上的标记及其潜在的测量伪影。PMHS脊柱在低速和高速时表现出不同的行为。在低速时，头部和上脊柱节段在达到最大向前位移时落后于脊柱下部和骨盆（头部最大向前偏移时间为254.3±31.9毫秒，骨盆为140.3±9毫秒），而在高速时这些差异最小（头部为127±2.6毫秒，骨盆为116.7±3.5毫秒）。假人没有表现出这种速度依赖性行为。此外，无论速度如何，假人的向前位移始终小于PMHS所表现出的位移。使用逆动力学技术估计PMHS寰枕关节处的颈部负荷，并与在假人中测量的负荷进行比较。发现PMHS上颈部的轴向力、剪切力和弯曲力矩高于在假人中测量的数值。
