Response of a Realistic Human Head-Neck Model to Impact

A structurally realistic model of the human head-neck system, consisting of a water-filled human cadaver skull and an artificial neck was subjected to pendulum impact under nondestructive conditions. The neck consisted of a series of neoprene and aluminum rings fabricated so as to faithfully reproduce the head motion of living persons in the saggital plane. Both an aluminum spherical shell and a solid steel sphere were employed to produce contact durations of the order of 1–6 ms and 0.2–1 ms, respectively, depending upon whether the impact occurred against the bare skull or against one of several scalp simulators used. Both frontal and occipital blows were produced on the system. A series of pressure transducers were suspended along the impact axis that measured the history of this parameter for the various conditions employed, and a crystal transducer arrangement ascertained the force input to the system. A displacement gage was utilized to record the excursion of the head-neck junction. Significant differences in pressure response were noted between frontal and occipital blows without protective covers that disappeared when scalp simulators were employed. The response characteristics in the present tests were much simpler than in corresponding tests using an acrylic shell for the head model, where pressures under similar impulsive loading conditions were at least an order of magnitude larger; this difference is attributed to the layering effect of the real skull relative to the homogeneous shell previously used.