The effect of using backpacks with different weights on plantar kinetics and balance variables among adolescent females during walking

Schoolchildren have to use backpacks every day on routes with different characteristics and weights to carry their staff. However, the knowledge available on its effects on walking biomechanics is very limited. The purpose of this study was to investigate the effect of using backpacks with different weights on plantar kinetics and balance variables among female students during the stance phase of walking.

Twenty female students in the age range of 14-17 with available sampling participated as subjects in this semi-experimental study. Participants carried backpacks with 10%, 15%, and 20% of body weight during walking. Plantar pressure data of subjects was collected by a foot pressure system. Repeated measure ANOVA was run to analyze the obtained data.

The results showed that the force in the heel medial and fifth metatarsal were significantly lower in 10% of body weight as compared to 15% (p=0.045) and 20% (p=0.038) body weight. Also, heel rotation in carrying a backpack with 20% of body weight was significantly greater than 10% of body weight (p=0.031).

According to the results, it seems, that increasing the weight of a backpack can alter the pattern of force distribution in the foot during walking. Changing foot biomechanics leads to poor posture adjustment and raises the risk of muscle-skeletal injuries among school students.