Effect of variable backpack load and strap option on the pulmonary function of children: A simulation using treadmill walking

BACKGROUND The restrictive effect of backpack loads on chest expansion has been widely reported but little is known whether pulmonary function in children is affected by the placement of the straps of the backpack. OBJECTIVE To determine the effects of strap configuration and backpack loads on pulmonary function among school age children. METHODS Eighteen children (mean age of 12±1.68 years) participated in this study. Pulmonary functionwas assessed using spirometryat baseline and during five test conditions. Two strap configurations were compared: double straps with the backpack worn midline on the back with one strap over each shoulder and single strap with the backpack worn laterally with one strap over the shoulder. RESULTS A marginal increase was shown in all measures of pulmonary function during standing and walking, and as the backpack weight increased. However, all the marginal changes in pulmonary function tests across different weights and strap patterns were not statistically significant. CONCLUSION Variable backpack loading and strap options appear to influence changes to the pulmonary function of children. Although the observed changes are marginal, it could not be determined if they have a long term effect. Further investigations of larger sample size are required to inform practice.