Stabbing angle alters peak force and work during sharp force trauma of porcine ribs

Forensic anthropologists have traditionally relied on a qualitative scale (mild, moderate, severe) for describing the forces required to generate a bony injury; however, recently efforts have focused on providing more quantitative data. The current study considers the effects of blade angle on the peak force, average force, and work measured during an instrumented sharp force impact. Sixty-two porcine side ribs were stabbed with the long axis of the blade perpendicular to the convex surface and the blade edge in one of three orientations (0°, 45°, 90°). Peak force was highest when the cutting edge was perpendicular to the long axis of the rib (90°) and lowest when it was aligned (0°). Conversely, work was highest when the blade was at an oblique angle (45°) to the rib. These results confirm that the orientation of a sharp force event must be considered when estimating the mechanical loading required to generate an injury.