Sex-based effects of shock energy exposure in warfighters

Personal armors were initially designed to fit against the male torso, as men previously filled roles requiring them, thus not made to accommodate the female anatomy. As a result, armor worn by female warfighters tends to have non-form fit in the waist, armpit, bust, and collarbone areas, causing reduced coverage. Shifting, riding up, air gaps, breathing difficulty, and physical discomfort have also been observed. Although this has been documented, the impact on the armor's protective capabilities has not been well studied. To address this, this study compared the protective capabilities of unisex armor for male and female warfighters from shock threats. Instrumented manikins were exposed to free-field blasts to assess pressure exposure in as-worn conditions. Directionality effects were considered in this study, using five directions from the shock source. It was found that the most harmful exposure to both warfighters occurred during a head-on interaction, with average impulse values 9.7%-72.6% higher than other orientations and peak pressures being 111.0 and 107.9 kPa, respectively. Moreover, a female body shape altered armor fit to increase impulses by up to 78.6%, relative to no armor being worn. This result was not observed for the male warfighter, though peak pressures were reduced for both.