A investigation of the relationship between fracture type and force: blunt force trauma on mammalian juvenile ribs (Sus scrofa, linneaus)

Abstract

The interpretation of bone trauma is an important aspect in understanding the circumstances within a death investigation (1-3). Proper interpretation of fractures can aid in identifying the number of blows, impact sites, the order in which they occur and the amount of force required to inflict such wounds (1,2). Yet there is a paucity of research regarding the force applied through the utilization of blunt implements used to inflict trauma. Such a study has the potential of more accurately characterizing the trauma, with regard to the amount of force used to create observed fracture patterns. In this preliminary study, a computer controlled impacting machine was used to inflict direct trauma onto several full, semi-fleshed racks of juvenile pig ribs (Sus scrofa, Linneaus) with a hammerhead attachment (n=36). Although there has been a recent interest in fracturing devices (2, 4-6), this one differs in that it mimics the arching motion of a human overhand swing, and is able to inflict trauma onto fully fleshed and intact specimens. After each strike the force at the moment of impact was recorded and was later paired with its corresponding fracture. From there, the range of force associated with transverse, oblique, spiral, greenstick, and comminuted fractures, as well as having no fractures at all were examined in light of the recorded forces. Such results were compared to those of others performed prior to work on the machine to determine if such relationships were consistent between studies. In this study it was discovered that there is no threshold where one fracture group will start and another will end.