Comparative effect of backpack carrying on cystic fibrosis and healthy children: a randomized crossover controlled trial

Abstract

Introduction: Backpack carrying restricts lung function and exercise capacity in healthy children. However, schoolbag consequences are unclear in a chronic respiratory disease context like school-aged cystic fibrosis (CF) children. Objectives: Our main aim was to compare forced vital capacity (FVC) change according to backpack carriage and straps position in children with CF and healthy controls. Secondary objectives were to assess other lung function parameters and track ventilatory response while walking with a backpack. Methods: Lung function was tested in three conditions: without backpack (control condition) and while carrying a 12.5% of child’s body weight backpack with bilateral strap (BB) or with unilateral strap (UB). Ventilatory responses were quantified while performing a mild intensity 10 minutes walking period. Results: Nine CF children (age 13.3±2.6 years and FEV1 66±22% predicted value) and 18 healthy controls (age 13.8±1.8 years) participated in this study. Similar FVC reduction was found in CF children and healthy controls. FVC was lower in UB when compared to NB (68.5±23.3% vs 72.1±24.3%, p=0.024) in CF group. CF children underwent a greater diminution on FEV1 (-6.5±4.3% vs -2.4±3.6%, p=0.017) and maximal inspiratory pressure (-12.5±16 vs -6±11.8cmH2O, p=0,048) with UB compared to their healthy peers. Walking with UB induced greater oxygen consumption, respiratory rate and minute ventilation in CF group than in control group. Conclusion: Unilateral backpack carrying leads to greater change on lung function parameters and ventilatory response in CF children than in healthy children. This position may be discouraged for CF school-aged children