The Mechanism of Skull Fracture

Abstract

Strain sensitive lacquer was applied to the external and internal surfaces of skulls. Tension stresses produce cracks in the lacquer. The following results emerged from "stresscoat" studies. The area of impact is inbended, and in discrete regions of the skull there are evidences of outbending if the energy expenditure is adequate. If the area of inbending following impact rebounds without fracturing locally, a linear fracture may be initiated at a distance from the area of in-bending due to tearing apart forces from outbending of the skull. If the area of inbending fails due to the magnitude and velocity of the blow, a depressed fracture is obtained. Whether a depressed or a linear fracture is obtained depends entirely upon the velocity, the kinetic energy and, to a less extent, the shape of the injuring object.