The potential injury risk of backpack weight on posture and ground reaction forces of obese children during stair descent

This study investigated the effects of backpack weight on posture, gait pattern, and ground reaction forces for children with obesity in an attempt to define a safe backpack weight limit for them. A total of 16 obese (11.19±0.66 years of age) and 21 normal body weight (11.13±0.69 years of age) school boys were recruited. Two force plates and two video cameras were used. Multivariate analysis of variance with repeated measures was employed. Obese children showed increased trunk and head forward inclination angle, increased ground reaction force in the medial-lateral and anterior-posterior directions when compared to male children with a normal body weight. The changes were observed even with an empty backpack in comparison with normal body weight children and a 15% increase in backpack weight led to further instability and damage on their already strained bodies.