The effects of mass, bulk and stiffness of personal protective equipment and clothing on physical performance when performing a military mobility obstacle course

Abstract

BackgroundSoldiers are required to conduct tasks and operations in physically demanding situations, where the ability to move (mobility) quickly is important to lethality and survivability.This study employed a specially designed suit to try to isolate the main mass property characteristics of personal protective clothing/equipment (PPCE) including mass, bulk and stiffness as much as possible and evaluated their effects on soldier performance across operationally-relevant mobility tasks. MethodEight male military subjects performed the load effects assessment program (LEAP) obstacle course while wearing 7 different configurations of specifically designed suit: unencumbered (control), 10 kg mass, 30 kg mass, 20 L bulk, medium stiffness, high stiffness and a mixed configuration consisting of 10 kg mass, 20 L bulk and medium stiffness. The primary outcome measure was total LEAP completion time. Additionally, heart rate, rating of perceived exertion (RPE), range of motion and vertical jump heights were measured and related to LEAP performance. ResultsAll configurations degraded or tended to degrade the total LEAP completion times (p-value < 0.05), except for the medium stiffness configuration. Heart rate did not differ significantly between configurations, while RPE scores of configurations 30 kg and mix were significantly higher compared to control (p < 0.01). ConclusionMass, bulk and stiffness all negatively influence LEAP obstacle performance. Therefore, all three have to be considered when trying to reduce the physical burden on soldiers.