Characterizing Relationships Among the Cognitive, Physical, Social-emotional, and Health-related Traits of Military Personnel.

INTRODUCTION: Personnel engaged in high-stakes occupations, such as military personnel, law enforcement, and emergency first responders, must sustain performance through a range of environmental stressors. To maximize the effectiveness of military personnel, an a priori understanding of traits can help predict their physical and cognitive performance under stress and adversity. This work developed and assessed a suite of measures that have the potential to predict performance during operational scenarios. These measures were designed to characterize four specific trait-based domains: cognitive, health, physical, and social-emotional. MATERIALS AND METHODS: One hundred and ninety-one active duty U.S. Army soldiers completed interleaved questionnaire-based, seated task-based, and physical task-based measures over a period of 3-5 days. Redundancy analysis, dimensionality reduction, and network analyses revealed several patterns of interest. RESULTS: First, unique variable analysis revealed a minimally redundant battery of instruments. Second, principal component analysis showed that metrics tended to cluster together in three to five components within each domain. Finally, analyses of cross-domain associations using network analysis illustrated that cognitive, health, physical, and social-emotional domains showed strong construct solidarity. CONCLUSIONS: The present battery of metrics presents a fieldable toolkit that may be used to predict operational performance that can be clustered into separate components or used independently. It will aid predictive algorithm development aimed to identify critical predictors of individual military personnel and small-unit performance outcomes.

Comparison of Hybrid-III and postmortem human surrogate response to simulated underbody blast loading.

Response of the human body to high-rate vertical loading, such as military vehicle underbody blast (UBB), is not well understood because of the chaotic nature of such events. The purpose of this research was to compare the response of postmortem human surrogates (PMHS) and the Hybrid-III anthropomorphic test device (ATD) to simulated UBB loading ranging from 100 to 860 g seat and floor acceleration. Data from 13 whole body PMHS tests were used to create response corridors for vertical loading conditions for the pelvis, T1, head, femur, and tibia; these responses were compared to Hybrid-III responses under matched loading conditions.

Post Mortem Human Surrogate Injury Response of the Pelvis and Lower Extremities to Simulated Underbody Blast.

Military vehicle underbody blast (UBB) is the cause of many serious injuries in theatre today; however, the effects of these chaotic events on the human body are not well understood. The purpose of this research was to replicate both UBB loading conditions and investigate occupant response in a controlled laboratory setting. In addition to better understanding the response of the human to high rate vertical loading, this test series also aimed to identify high rate injury thresholds. Ten whole body post mortem human surrogate (PMHS) tests were completed using the University of Virginia's ODYSSEY simulated blast rig under a range of loading conditions. Seat pan accelerations ranged from 291 to 738 g's over 3 ms of positive phase duration, and foot pan accelerations from 234 to 858 g's over 3 ms of positive phase duration. Post-test computed tomography (CT) scans and necropsies were performed to determine injuries, and revealed a combination of pelvic, lumbar, thoracic, and lower extremity injuries. The research in this paper discusses pelvis and lower extremity injuries under high rate vertical loads.