title: Effect of variable backpack load and strap option on the pulmonary function of children: A simulation using treadmill walking.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors: Department of Medical Rehabilitation, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria.
authors: U O
authors: UO
authors: Abaraogu
authors: Department of Medical Rehabilitation, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria.
authors: E B
authors: EB
authors: Kizito
authors: Department of Physiotherapy, Faculty of Clinical Sciences, College of Medicine, University of Lagos, Lagos,  Nigeria.
authors: U A C
authors: UA
authors: Okafor
authors: Department of Medical Rehabilitation, Faculty of Health Sciences and Technology, College of Medicine, University of Nigeria, Enugu Campus, Enugu, Nigeria.
authors: G C
authors: GC
authors: Okoye
mesh_terms: D000293:Adolescent; D002648:Child; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008448:Maximal Expiratory Flow Rate; D008450:Maximal Midexpiratory Flow Rate; D010366:Peak Expiratory Flow Rate; D014797:Vital Capacity; D000070857:Walk Test; D016138:Walking / Q000502:physiology*; D016474:Weight-Bearing / Q000502:physiology*
keywords: Pulmonary function tests; children; lifting/adverse effects; walking