Factors affecting performance on an army urban operation casualty evacuation for male and female soldiers

Abstract

Introduction: This study was conducted to determine what physical and physiological characteristicscontribute to the performance of an urban operation casualty evacuation (UO) and its predictive test, FORCE combat(FC) and describe the metabolic demand of the UO in female soldiers. Methods: Seventeen military members (9 M and8 F) completed a loaded walking maximal aerobic test, the UO and FC. Heart rate reserve (HRR) and completion timewere used as efficiency/performance measures. Oxygen consumption (VO2) was directly measured for UO on fivefemale participants with a portable indirect calorimetry system, and analyzed using descriptive statistics. Stepwise multiple regression analysis was used to determine the contribution of the non-modifiable (age, sex, height) and modifiablecharacteristics (lean body mass to dead mass ratio (LBM:DM), VO2max corrected for load (L.VO2max), peak force (PF)measured on an isometric mid-thigh pull (IMTP) and medicine ball chest throw distance (Dist) on to the performanceof each exercise. Results: LBM:DM and PF were the only factors included in the stepwise regression model for UO,predicting 70% of UO performance (p < 0.01). For FC, L.VO2max only was included in the stepwise regression modelpredicting 54% of FC performance (p < 0.01). Sex, age and height were not included in the regression model. Theaverage metabolic cost of UO was 21.4 mL of O2*kg-1*min-1 in female soldiers while wearing PPE. Conclusion:This study showed that modifiable factors such as body composition, PF on IMTP and L.VO2max are key contributorsto performance on UO and FC performance.