Effects of Two Backpack Weight Distributions on Perceptual and Physiological Measures During Walking

Backpack weight distribution may affect economy by conserving energy and thus potentially prolonging fatigue. Research has not however examined effects of backpack weight distribution on subjective measures of intensity and comfort. Heart rate (HR) and overall and differentiated Ratings of Perceived Exertion (RPE) were examined during simulated backpacking with differentially weighted backpacks. Volunteers (n=27) completed two simulated hiking trials on a treadmill. Trials consisted of 15 minutes walking at 0% grade followed by 15 minutes walking at 10% grade at 2.5 mph (males) or 2.0 mph (females). Subjects wore an internal frame backpack packed to contain 25% of their individual body weight). In a counterbalanced order, packs were placed with either a high weight distribution (HWD) (3:1:1 ratio) placing more weight near the shoulders, and a low weight distribution (LWD) (1:1:3 ratio) placing more weight near the hips. Heart rate (HR), RPE-Overall, RPE-Legs, RPEShoulders, and RPE-Back were recorded every three minutes and compared between trials using repeated measures ANOVA. HR between HWD and LWD was similar at 0% as well as 10%. Overall and differentiated RPE\u27s were not significantly different between (HWD vs. LWD) at 0% or 10%. Results suggest backpack weight distribution (HWD vs. LWD) does not significantly influence HR and perceptual measures during simulated hiking at a 0% or 10% grade