Finite element analysis of head–neck kinematics during motor vehicle accidents: Analysis in multiple planes

In this study, a detailed three-dimensional head–neck (C0–C7) finite element (FE) model developed previously based on the actual geometry of a human cadaver specimen was used. Five simulation analyses were performed to investigate the kinematic responses of the head–neck complex under rear-end, front, side, rear- and front-side impacts. Under rear-end and front impacts, it was predicted that the global and intervertebral rotations of the head–neck in the sagittal plane displayed nearly symmetric curvatures about the frontal plane. The primary sagittal rotational angles of the neck under direct front and rear-end impact conditions were higher than the primary frontal rotational angles under other side impact conditions. The analysis predicted early S-shaped and subsequent C-shaped curvatures of the head–neck complex in the sagittal plane under front and rear-end impact, and in the frontal plane under side impact. The head–neck complex flexed laterally in one direction with peak magnitude of larger than 22° and a duration of about 130 ms before flexing in the opposite direction under both side and rear-side impact, compared to the corresponding values of about 15° and 105 ms under front-side impact. The C0–C7 FE model has reasonably predicted the effects of impact direction in the primary sagittal and frontal segmental motion and curvatures of the head–neck complex under various impact conditions.