THE EFFECT OF TIGHTNESS OF FIT OF A BACKPACK ON ENERGY COST, LUNG FUNCTION AND POST-JUMP BALANCE

  • Sally Bygrave
  • Stephen Myers
  • Michael Llewellyn
Keywords: energy cost, balance, lung function

Abstract

INTRODUCTION: The carriage of heavy loads by military personnel is associated with increased energy consumption, fatigue and discomfort. Together these may reduce performance. In extreme cases, injuries can occur. Since movements of the body are a consequence of bipedal gait, any load carried on the body also moves. As walking speed increases, the displacement of the body, particularly in the vertical axis, increases. Previous studies (Legg & Mahanty, 1985, Legg et al, 1992, Soule et al, 1978) found increases in walking speed had a greater impact on energy consumption than increases in load. Studies into different modes of carrying loads have shown no significant effect on cardiorespiratory and metabolic costs. One way to minimise the energy consumption of load carriage might be to provide a suspension system that minimises the excursion of the load being carried. However, there are insufficient data to indicate whether such a system, even if it could be built, would significantly reduce energy consumption and thus maintain desired performance. The purpose of this study was to investigate whether changing the tightness with which a backpack was fitted to the torso had any consequence on the energy consumption and biomechanics of gait.