Kinematic and electromyographic analysis of school children gait with and without load in the backpack

Abstract

Introduction: Excessive load on the backpacks can lead to musculoskeletal injuries and gait alterations. The objective of this study was to analyze the electromyographic (EMG) activity in association to the kinematic during the stance and balance phases of gait performed with and without the use of the backpack. Methods: Twelve volunteers have executed a gait cycle in 3 tasks: without the school backpack (SM), with a backpack with load equivalent to 10% (M10) and 20% (M20) of the body weight (BW). It was evaluated the ankle, knee and hip angular excursion (AE), linear displacement (LD) of the toe and ankle, knee, hip, shoulder, head and EMG activity of the tibialis anterior (TA), vastus medialis (VM), rectus abdominis (RA), gastrocnemius lateral (GL), biceps femoris (BF) and spinal erector (EE) muscles. Results: In the LD in the stance phase there was an AP increase for the toe and ankle, hip and head (p<0.043). In the balance phase for VT (vertical) direction, the shoulder presented a smaller displacement as well as the toe, ankle, knee, hip, shoulder and head in the ML direction. In the AP direction, the toe displacement was smaller as well as the ankle (p < 0.038). The AE in both phases was smaller for the hip (p <0.006). In the balance phase the IEMG was higher for the RA (p = 0.034). Conclusion: These results suggest that the transport of school backpacks with loads of more than 10%BW causes changes in the kinematic and in the muscular recruitment pattern.

The Influence of the Weight of the Backpack on the Biomechanics of the Child and Adolescent: A Systematic Review and Meta-analysis With a Meta-Regression

“…The study strategy is graphed in Figure 1. A total of 27 studies were included: 13 nonrandomized crossover trials13,16,38–48 and 14 randomized crossover trials 49–62. There were 1348 children and adolescents.…”

“…Sixteen of the studies were from Asia,13,16,40,44–49,51–54,59,61,62 4 were from Europe,50,55–57 2 from South America,38,58 2 from Africa,41,42 1 from North America,60 1 was from Oceania,39 and 1 from the Middle East 43…”

“…The method quality of the randomized trials was evaluated with the PEDro scale. Seven were rated as having good method quality, 49,50,53,55,[57][58][59] 6 as having low method quality, 51,52,56,[60][61][62] and 1 had very low method quality. 54 The items with the lowest score were the allocation concealment and blinding.…”

“…All studies had high risk of bias. [49][50][51][52][53][54][55][56][57][58][59][60][61][62] The domain with the highest percentage of studies with a high risk of bias is bias arising from the randomization (100%). The risk of bias summary of the randomized trial is shown in Supplemental Digital Content 5, available at: http://links.lww.com/PPT/A438.…”

The relationship between neck angles and ground reaction forces in schoolchildren during backpack carriage

“…A recent study conducted on primary school students found that the heavier the school backpack was, the higher was the pressure and force distribution under different foot regions [1]. Moreover, carrying school backpacks with loads of more than 10% BW causes changes in the gait kinematics [23].…”