How a soldier's load is carried can elicit different physical and physiological costs on the carrier. As such, this study aimed to profile and compare the impacts of three different load carriage backpack systems on physical and physiological outcomes during and following a load carriage march. Twelve soldiers were randomly allocated to one of three pack variants (Variant A, B, or C) using a Latin Square design and completed three 5 km load carriage marches (30 kg at 5.5 km/h) over three separate sessions wearing the different Variants for each march. Outcome measures during the march were heart rate and oxygen consumption and pre and post march were a counter movement jump, grip strength, and postural sway. There were no significant differences (p > 0.01) in any of the objective outcome measures across pack Variants. These results suggest that load weight will impact on the physical and physiological costs associated with load carriage to a greater extent than military backpack design.
Orr et al. (Sat,) studied this question.