HYBRID III CHEST RESPONSE TO SIMULATED PROJECTILES AND HAND-HELD WEAPON THREATS REPRESENTATIVE OF CROWD MANAGEMENT SCENARIOS

摘要

This study was motivated by the lack of information in the biomechanical literature about chest response to blunt impacts typically encountered in Crowd Management Intervention (CMI). Typical CMI threats are low-mass, high velocity objects falling into two categories: projectiles and hand-held weapons. Although abundant, data on chest response to impact from research in the automotive area is not suitable for the CMI context, since it pertains to low impact speeds generated with high-mass objects. In this study, projectiles were simulated by hard balls of mass corresponding to typical projectiles encountered in riot environments. The balls were propelled using an air cannon. To simulate hand-held weapons, a standard baseball bat was attached to a rotating cam of a Blunt Impactor apparatus. A Hybrid III chest was impacted at the sternum level. Average peak velocities of chest deflection of 13.9 and 5.2 m/s were observed for impacts with the projectiles and the bat, respectively. The corresponding viscous responses based on VC{sub}(max) were 0.425 and 0.232 m/s. For both impact modes, the probability of an AIS score ≥4estimated at 10%, based on an analysis method developed for similar impact conditions. A 20% likelihood of ventricular fibrillation was also noted.