The effect of backpack load placement on physiological and self-reported measures of exertion.

Abstract

Backpacks are the most popular way of carrying additional weight; however, it puts the body under physical stress and may cause discomfort. It may also increase oxygen demand and energy cost. Manipulation of load placement may relieve the effects carrying a backpack has on the body. This study investigated physiological and self-reported measures of exertion, movement economy and efficiency, carrying a loaded backpack in high and low load placement compared to a control condition. Fifteen healthy adults were examined under three load conditions: no load, carrying a 20% of body weight in high and low load placement. Dependent variables were measured using a metabolic measurement system and participants rated their perceived exertion on a Borg scale. Carrying load produced a significant increase in VO2, minute ventilation, heart rate, movement economy and overall perceived exertion in both load placements compared with the no backpack condition. However, no difference was observed between the high and low load placement conditions. While altering load placement did not influence physiological variables or overall exertion, participants reported lower perceived exertion on the shoulders in low load placement and low load placement might be preferable in this respect.