[Observations of the propagation velocity and formation mechanism of burst fractures caused by gunshot].

In ballistic literature bursting fractures of the skull in gunshot wounds of the head are understood to be produced by the high pressure built up in the cranial cavity as a result of temporary cavity formation. On one hand there is known, that maximum expansion of the temporary cavity does not occur until some time after the bullet has passed through the skull. On the other hand there exist observations that bursting fractures originating from entrance hole traversed the skull more rapidly than did the projectile. In this paper there is presented a case with such a phenomenon in humerus. Since the determined fracture propagation velocity is very high, there is postulated a direct formation mechanism preceding the indirect effect of the temporary cavity. This hypothesis is confirmed by experiment.