HEAD EXCURSION OF SEAT BELTED CADAVER, VOLUNTEERS AND HYBRID III ATD IN A DYNAMIC/STATIC ROLLOVER FIXTURE. IN: OCCUPANT AND VEHICLE RESPONSES IN ROLLOVERS

In rollover accidents, seatbelted occupants sustain a lower fatality rate compared to unbelted occupants, primarily due to lower risk of ejection. However, seat belts do not typically prevent head contact with the vehicle interior during a rollover, due to occupant torso and head excursion. This chapter on head excursion of occupants is from a comprehensive text on occupant and vehicle responses in rollovers. In this chapter, the authors report on a total of 80 excursion tests: 51 tests with a Hybrid III 50th percentile male anthropomorphic test devices (ATD); 18 tests with a cadaver; and 11 tests with two male volunteers. Results indicate that vertical head excursion was minimized with a steep lap belt angle and short webbing length, in tests using a two-point lap belt. Tests using a three-point lap and torso restraint showed that the torso belt reduced vertical head excursion primarily by restricting forward torso rotation. The authors also note that the ATD had less vertical excursion than either the volunteers or the cadavers; while the ATD is a useful tool in testing the effectiveness of restraint systems, it may not fully simulate vertical and lateral head excursion of humans in rollover conditions.