Biomechanical, Physiological, and Agility Performance of Soldiers Carrying Loads: A Comparison of the Modular Lightweight Load Carrying Equipment and a Lightning Packs, LLC, Prototype
Technical Report,01 Sep 2015,31 Oct 2015
ARMY NATICK SOLDIER RESEARCH DEVELOPMENT AND ENGINEERING CENTER MA NATICK United States
Pagination or Media Count:
This report details a laboratory evaluation that compared a medium U.S. Army standard-issue Modular Lightweight Load-carrying Equipment MOLLE rucksack and a prototype energy-harvesting backpack from Lightning Packs LP, LLC. A payload of 27.2 kg 60 lb was placed in each pack. The total weights of the MOLLE and the LP were 30.1 kg 66.4 lb and 34.6 kg 76.3 lb, respectively. The evaluation focused on comparing the two rucksack systems with regard to their effects on the biomechanical, physiological, and agility performance of Soldiers. The energy generation capabilities of the LP were also examined. Twelve male enlisted U.S. Army Soldiers 24.5 or - 3.9 years 177.4 or - 5.8 cm 84.3 or - 10.2 kg participated in this evaluation. Gait kinetics, kinematics, and metabolic responses were measured during treadmill walking at a speed of 1.34 ms-1 3.0 mh-1 on 0 , 5 , and -5 treadmill grades, as well as at 1.61 ms-1 3.6 mh-1 at a 0 grade. Participants also completed a maximal effort agility drill in both pack configurations. The findings indicate that carrying the LP prototype is less metabolically efficient than carrying the MOLLE. The LP also affects the biomechanics of walking differently than the MOLLE, with significant differences in forward trunk lean angle, hip angle, and sagittal plane hip moments. In terms of energy harvesting and production during walking, the current weight penalty of carrying the LP prototype overrides the benefit of the energy harvesting capability of the prototype. Recommendations are made to improve performance of future LP systems.