Publication:
Effects of a modified backpack model on ground reaction forces in children of different ages during walking and running

Consultable a partir de

Date

2022

Authors

Barbosa, João
Marqués, Mário C.
Forte, Pedro
Santos, Catarina C.
Neiva, Henrique P.
Marinho, Daniel

Director

Publisher

IMR Press
Acceso abierto / Sarbide irekia
Artículo / Artikulua
Versión publicada / Argitaratu den bertsioa

Project identifier

Abstract

Background: Backpacks are widely used by children to carry different objects and the literature supports that most backpacks contain excessive weight. To minimize the loading effects (i.e., ground reaction force), modified backpacks have been tested. However, the effects of elastics on shoulders straps are yet to be studied. Thus, the aim of this study was to test and compare the effect on the vertical ground reaction force of a standard backpack with a modified one with elastic straps while walking and running. Methods: 9 children (5 boys and 4 girls) were included in the group G-5 (age: 11.0 ± 0.3 years-old; body mass: 35.3 ± 7.3 kg; height: 1.41 ± 0.1 m) and twelve (7 boys and 5 girls) in G-9 (age: 15.0 ± 0.7 years-old; body mass: 56.7 ± 11.2 kg; height: 1.63 ± 0.1 m). Participants attended a single session and were initially asked to walk and then run over a force plate. The software Ergotest MuscleLab v8.0 (MuscleLab, Ergotest Innovation, Porsgrunn, Norway) was linked to the force platform and was used to collect and export data. The level of statistical significance was set at p ≤ 0.05. Additionally, the effect size of the differences verified on T-Tests was calculated based on Cohen’s d. Results: Statistically significant differences between a common backpack and a modified one with straps (p < 0.05) were observed for the variables time and force when walking. Regarding the running condition, the time variable did not differ significantly between the backpacks. However, the force variable changed considerably between backpack types (p < 0.05). The new straps minimized the forces magnitude, resulting in lower stress. Conclusions: The modified backpacks with shoulder elastic straps reduced the ground reaction force and impact when walking and running. The study may encourage other researchers to assess the effects of different movements (such as jumping or rotating) on ground reaction force.

Keywords

Backpacks, Modified straps, Ground reaction forces, Locomotion

Department

Ciencias de la Salud / Osasun Zientziak

Faculty/School

Degree

Doctorate program

Editor version

Funding entities

This work is supported by national funding through the Portuguese Foundation for Science and Technology, I.P., under the project UIDB/04045/2020.

© 2022 The Author(s). This is an open access article under the CC BY 4.0 license.

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