An investigation of hybrid III and living human drop tests

The effect of roof crush on restrained occupants has often been discussed without regard to the headroom available, effectiveness of belts, and location of roof crush. In this article, the question of the ability to protect a simply restrained occupant in an environment in which the roof does not crush is addressed. The subjects were inverted and dropped vertically in noncrushable production vehicle compartments and a specially designed drop fixture. Data collected includes head accelerations, vehicle accelerations, head displacements, belt angles, anchor point location, seat position, and belt tension for a variety of occupant sizes. To our knowledge, these are the first inverted living human vertical studies to be scientifically documented and reported. It was found that no head or neck injuries resulted from drops of up to 91 cm and velocities up to 4.2 m/sec for restrained occupants in the absence of roof crush.