Research on the Effect of Backpack With Anti Gravity System Design on Relieving Users’ Perceived Exertion

Abstract

The mechanism of Anti Gravity System (AGS) backpack lies in the use of highly elastic shoulder straps to create a bouncing motion when the user walks, thus the user doesn't feel the constant load of the bag, which is similar to the ancient Chinese folk transporting tool "BianDan" in work principle. Theoretically speaking, under the same load, this results in a feeling of reduced exertion to users as compared to ordinary backpack. In this paper, a comparative study was made to test the effect of AGS backpack on relieving perceived exertion to users. Two trials were conducted to respectively record the scores of perceived exertion reported by 10 healthy male subjects carrying a loaded AGS backpack and an ordinary backpack on their backs under walking state. The variations of subjective fatigue scores in the 30-minute weight-bearing walking process were compared between two trials. The results showed that for 3 out of 10 subjects, the variation of perceived exertion caused by different types of backpacks were significantly different (P<0.05). AGS backpack group also displayed a slower growth of mean perceived exertion score and a decreasing tendency of standard deviation. It was concluded that given the condition of appropriate weight-bearing and walking speed, the backpack with AGS design could give users a labor-saving feeling and more regular growth of subjective fatigue compared with ordinary backpack.