Effects of backpack use on the kinematics and kinetics of the standing posture of young and elderly people

Abstract

[Purpose]: The purpose of this study was to examine the kinetic and kinematic effects of wearing a backpack with different loads on the standing posture. [Subjects]: Sixteen healthy young and 8 healthy elderly subjects participated in this study. [Methods]: We measured the standing posture using a three-dimensional motion analysis system and force plates, and compared kinetic and kinematic changes among three different conditions: without a backpack, with a backpack of 5% of body weight (BW) and with 15% of BW. [Results]: Lumbar flexion moment and pelvic forward tilt angle significantly increased with increase of weight of the backpack in both subject groups. Hip flexion moment significantly increased in the young subjects and tended to increase in the elderly subjects. [Conclusion]: Increase of the weight of the back pack decreased the low back load and this phenomena was observed in both subject groups.