Comparison of selected perceptual variables for backpacks with internal and external frames

Differences in perceptions of comfort, exertion, balance, and heart. rate w ere investigated with two types of backpack. Subjecrs were 20 male voluntee rs (M age = 24.3 yr., SD: 3.6, M height = 180.02 cm, SD: 8.0, and M weight = 86.46 kg, SD: 14.84). Following oral briefing and practice trials, each s ubject was fitted at random with either an internal- or external-frame back pack containing 18.2 kg. By ran dom, cross-over design, subjects completed a 30-m simulated hiking trail consisting of 16 separate obstacles designed to resemble actual off-trail hiking. Trials were conducted in a controlled environment with the walking intensity regulated by a metronome. Upon compl etion of each trial, the subjects rated the experience on perceived comfort , balance and stability, and rating of perceived exertion. Heart rate was r ecorded immediately prior to and following each trial. Analysis yielded a s ignificant difference only on rating of perceived exertion in favor of the internal-frame backpack. Under limited circumstances, these data suggest th at both types of backpacks provide similar comfort and balance and stabilit y; however, internal frames in backpacks may reduce perceived exertion duri ng short, demanding hikes.