Background: Backpack syndrome (BS) is a term used to describe symptoms such as shoulder and back pain that are believed to be caused by carrying a backpack. Few studies have investigated the changes in walking and running parameters with and without backpacks.
Objective: The present study aimed to investigate the differences in walking and running parameters with and without backpacks in primary school children with and without BS.
Methods: This cross-sectional study included 51 children (average age 9.3 years, 6- 12 years). Two questions were asked beforehand: whether the respondents had shoulder or back pain when going to school and present; those who answered that they had pain in both cases were defined as the BS group, while the others were the control group. Walking and running at comfortable speeds and walking and running with a 6 kg backpack on their backs were measured.
Results: During walking, there were main effects for speed, cadence, and strike angle with and without the backpack, but no interactions were identified for any of the parameters. In running, however, there were main effects for speed, stride length, strike angle, and lift-off angle, and an interaction effect was observed for speed and stride length.
Conclusions: During walking, carrying a 6 kg backpack increased cadence and walking speed. During running, carrying a backpack caused a decrease in stride length and running speed in the BS group, whereas there was no change in the control group, suggesting that the control and BS groups may respond differently.
Keywords: Backpack; back pain; backpack syndrome; elementary school students; running; shoulder pain; walking.