The impact velocity and bone fracture pattern: Forensic perspective

This study has two objectives, to establish a usable fracture analysis method and to reveal the association between the energy of the force and the fracture pattern. Dynatup Model POE 2000 (Instron Co.) low energy pendulum impact machine was utilized to apply impact loading on fresh pig femoral bones (n = 30). The bone clamp shaft was adjusted to position the bone for three-point bending with additional bone compression. Three different velocities of the forced applied were carried out. On average, the number, length and the curviness of the fracture lines created under moderate and high-energy impact is significantly higher compared to a low-energy impact. Most fractures lines were located on the impacted aspect in bones subjected to moderate- and high-velocity impact. Four oblique-radial fracture lines running from the point of impact creating a double butterfly pattern were found in bones subjected to moderate and high-velocity impact. Only “false” wedge-shaped (butterfly) fragments were found in the current study. Our results suggest an association between fracture pattern and the velocity of the impact.