Unisex Combat Armor Traps Lethal Blast Energy on Female Torsos Due to Poor Fit, Study Finds

A 2026 study finds that unisex body armor creates air gaps on female torsos that trap blast energy, increasing impulse exposure by 79%.

By: AXL Media

Published: Apr 7, 2026, 6:02 AM EDT

Source: Information for this report was sourced from Medical News

The Hidden Mechanics of Impulse Exposure

As women occupy increasingly prominent roles on the modern battlefield, the limitations of "one-size-fits-all" equipment are becoming a matter of life and death. A recent experimental study utilized anatomically representative manikins—complete with silicone skin, rib structures, and realistic breast anatomy—to test standard Small Arms Protective Insert (SAPI) plates under blast conditions. While the armor successfully reduced peak pressure for both sexes, researchers discovered a troubling side effect: the female body shape creates larger air gaps between the torso and the plate. These gaps, reaching up to 2.97 cm in females compared to 1.59 cm in males, allow shock energy to become "trapped," significantly prolonging the duration of pressure exposure.

Anatomical Misfit and Energy Entrapment

The study demonstrated that breast anatomy alters the positioning of protective plates, increasing the plate angle by 3.1 degrees in the female model. This shift contributes to a 73% higher average impulse value during head-on (0°) blast exposures compared to oblique angles. In the underbust region of the female manikin, the total impulse rose by up to 79% when compared to an unarmored state. High-speed videography using background-oriented schlieren (BOS) techniques captured the shock waves reflecting and diffracting around the armor edges, creating complex energy patterns that resulted in multiple pressure peaks for female wearers.

Limitations of Scaled-Down Male Designs

Historically, body armor has been designed around the male torso, with female versions often being mere scaled-down iterations of those original designs. This approach frequently results in poor fit across the bust, waist, and upper torso, leading to shifted coverage, physical discomfort, and restricted breathing. The 2026 study confirms that these fit issues are not just matters of comfort but are critical safety failures. The "lightness" of a poorly fitted plate allows shock energy to penetrate the gap, turning the space between the armor and the body into a localized pressure chamber that increases the risk of internal blast-related injuries.