A Systematic Literature Review of Impact Systems for Developing Generalized Medical Injury Criteria for Behind Armor Blunt Trauma.

INTRODUCTION

The focus of previous reviews on behind armor blunt trauma (BABT) as applied to the thoraco-abdominal region has been the rationale for the clay deformation-based standard of 44 mm and injuries from field and laboratory studies. The objective of this study was to conduct a systematic literature review of BABT studies with a focus on impact systems used to deliver high-rate compressive loads to the thorax and development of injury criteria in the form of risk curves for enhanced medical injury criteria.

MATERIALS AND

METHODS

The widely used PubMed database was accessed to identify articles for a systematic literature review ranging from its inception until November 15, 2024. The detailed review focused on articles covering thoraco-abdominal injuries using biological and other models, impact delivery systems, presence of body armor, and development of injury risk curves (IRCs).

RESULTS

The systematic review identified literature involving different surrogates in the database: human cadavers in 4, animals in 18, physical models in 10, and numerical simulations in 14 articles. Three field/case and 7 review articles were also identified in the database. Human cadaver research focused on the thorax and spine regions, while the swine studies targeted the lung, spine, liver, and heart regions. Behind armor blunt trauma impacts with actual round and different types of body armor to the live swine produced varying types of injuries and injury severities to skeletal structures and organ and soft tissue traumas. Although external metrics such as velocity and energy were reported, IRCs were not developed in live swine experiments. Impacts with indenter impact systems to the live swine without armor protection produced injuries similar to those with armor-covered and live fire round-based impact systems. These tests have the flexibility to gather several potential biomechanical correlates to injury that can be used to develop enhanced medical injury criteria from IRCs.

CONCLUSIONS

Because thoracoabdominal regions/organs are different in terms of anatomy, structure and physiology, their responses and tolerance to BABT are different. As organ/soft tissue injuries are physiological, that is, they develop over time, live animal experiments with indenter impact systems are needed to develop regional injury criteria/IRCs and to improve the current deformation-based BABT criterion without region specificity. Enhanced medical injury criteria will improve armor design, Warfighter combat safety, and medical readiness.