Open Access

ARTICLE

Effect of a Double Helical Spring Decompression Structure Backpack on the Lumbar Spine Biomechanics of School-Age Children: A Finite Element Study

Fengping Li¹, Dong Sun^1,*, Qiaolin Zhang^1,2,3, Hairong Chen^1,2,3, István Bíró^2,3, Zhiyi Zheng⁴, Yaodong Gu^1,*

1 Faculty of Sports Science, Ningbo University, Ningbo, 315211, China
2 Doctoral School on Safety and Security Science, Óbuda University, Budapest, 1034, Hungary
3 Faculty of Engineering, University of Szeged, Szeged, 6724, Hungary
4 Anta Sports Sciences Laboratory, Anta Group, Xiamen, 362212, China

* Corresponding Authors: Dong Sun. Email: ; Yaodong Gu. Email:

Molecular & Cellular Biomechanics 2023, 20(1), 35-47. https://doi.org/10.32604/mcb.2023.041016

Received 07 April 2023; Accepted 23 May 2023; Issue published 20 June 2023

Abstract

Background: A children’s backpack is one of the important school supplies for school-age children. Long-term excessive weight can cause spinal deformity that cannot be reversed. This study compared a double helical spring decompression structure backpack (DHSB) with a traditional backpack (TB) to explore the optimization of decompression devices on upper body pressure. The finite element (FE) method was then used to explore the simulation of lumbar stress with different backpacks, in order to prove that DHSB can reduce the influence of backpack weight on lumbar vertebrae, avoid the occurrence of muscle discomfort and spinal deformity in children; Methods: 18 male children subjects (age: 12.5 ± 0.6 years; height: 145.5 ± 1.9 cm; bodyweight: 40.8 ± 3.1 kg) ran with DHSB and TB at a speed of 3.3 ± 0.2 m/s. Flexible pressure sensors were used to measure the pressure on the shoulder, back, and waist during running. The pressure data was then inputted into the FE model to simulate the effect of carrying different backpacks on the stress of the lumbar intervertebral disc (IVD); Result: There was a significant difference in shoulder and waist peak pressure between the DHSB and TB during the running posture. At a speed of 3.3 ± 0.2 m/s, the peak pressure of the shoulder and waist decreased. After finite element analysis, it was found that carrying DHSB on the back could effectively reduce the intervertebral disc pressure between L4-5 and L5-S1 by 27.9% and 34.1%, respectively; Conclusion: DHSB can effectively reduce the pressure on the shoulder and waist when children are running and can reduce the influence of backpacks on children’s posture to a certain extent. By finite element analysis, it is found that carrying DHSB can effectively reduce the stress of the lumbar intervertebral disc, and the damage to lumbar vertebrae is lower than with a TB.

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