The specific aims of this study included:​ (1) the determination of human response corridors for blunt ballistic impacts of the thorax and comparison with established biomechanical responses from the automotive safety literature, (2) the determination of an injury criterion to assess the continuum of injuries related to blunt ballistic impacts of the thorax, (3) the refinement and validation of a biomechanical surrogate and subsystem test procedure for the evaluation of blunt ballistic impacts, and the evaluation and comparison of existing methods used by the non-lethal community in terms of biofidelity and injury assessment, (4) the development of theoretical models to estimate the effects of blunt ballistic impacts to the human and existing surrogates.

Three impact conditions were selected to biomechanically assess blunt ballistic impacts to the thorax. The conditions included (A) 140 g mass at 20 m/s (B) 140 g mass at 40 m/s and (C) 30 g mass at 60 m/s. Testing was conducted on cadaveric specimens, existing simulants used for penetrating munitions (clay and gelatin), a biomechanical surrogate (3-RCS), and a mathematical model (Lobdell). The cadaveric specimens provided information needed to develop human response corridors for the test conditions. After these responses were determined, the remaining surrogates were tested and compared to the corridors established.

The results indicate that ordinance gelatin does not display agreement with the human response corridors. Modification of the current behind body armor standard of clay indicates agreement with the human thorax but the information provided by this assessment is limited. A biomechanical surrogate, the 3-RCS, displays an adequate correlation with the force-time corridors established. A correlation factor between the 3-RCS and the human response was also established based on the injury parameter of the viscous response or VC. Logistic regression analysis was conducted on experimental data, which indicated the VC could predict the injuries seen with blunt ballistic impacts. Refinement of the Lobdell mathematical model was also completed in order to assess blunt ballistic impacts.

The results of this research provide an initial biomechanical assessment of blunt ballistic impacts. Further refinement of the biomechanical surrogate and the injury parameter in the future will allow for a complete assessment to be conducted in this area of impact biomechanics.