The effect of weapon handling during load carriage across a range of military-relevant walking speeds

This study investigated the effects of weapon handling on the physiological responses and walking-gait kinematics during load carriage. Seventeen soldiers completed four twelve-minute bouts of treadmill walking at incremental speeds (3.5, 5.5, 6.5 km^.h⁻¹ and self-selected) carrying 23.2-kg of additional load, while either handling a weapon or not handling a weapon. Physiological, perceptual and biomechanical outcomes were measured throughout each trial. A weapon-by-speed interaction (p <.05) was observed for hip flexion-extension during loading response and mid-swing. Weapon handling elevated (p <.05) cardiorespiratory responses at 6.5 km^.h⁻¹. Main effects (p <.05) of weapon handling were observed for ventilation, oxygen pulse, effort perception, stride length and knee flexion-extension during toe-off. No main effects of weapon handling were observed for any other biomechanical measures. These findings demonstrate that physiological and biomechanical responses to weapon handling are likely walking-speed dependent. Practitioner summary: Weapon handling is an important part of many load-carriage tasks but is rarely investigated. Physiological and biomechanical responses were assessed at incremental speeds during load carriage. Despite similar biomechanics, there was greater physiological demands at faster walking speeds, suggesting an increased contribution from isometric muscle contractions for weapon stabilisation.