Effects of a 6-Minute Fast-Walking Protocol on Changes in Muscle Activity in Individuals with Flatfoot

Chu-Yuan Chiang,Hui-Min Lee,Kuang-Wei Lin,Li-Wei Chou,Shun-Hwa Wei

doi:10.3390/app12042207

Chu-Yuan Chiang, Hui-Min Lee + Show 3 more

Open Access

https://doi.org/10.3390/app12042207

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Journal: Applied sciences	Publication Date: Feb 20, 2022
Citations: 3	License type: CC BY 4.0

Affiliation: National Yang Ming Chiao Tung University

Abstract

Flatfoot causes abnormal biomechanics in the lower extremity, resulting in discomfort and excessive burden on lower extremity muscles during functional tasks, and it potentially leads to associated syndromes in the lower extremity. The aim of this study was to investigate how a demanding, repetitive task affects the muscle strength, activities, and fatigue of the lower extremities during function tasks. Nineteen individuals with flexible flatfoot (10M9F, age: 24.74 ± 2.68 years) and fifteen non-flatfoot participants (6M9F, age: 24.47 ± 3.74) took part in this study. All participants performed maximal voluntary isometric contraction and functional tasks, including walking and single-leg standing tests before and immediately after a 6-min fast-walking protocol. A surface electromyography system was used to collect muscle activation data. Our results showed that, after 6 min of fast walking, peroneus longus activity increased only in the non-flatfoot group, and gastrocnemius activity increased in the flexible flatfoot group. In the flexible flatfoot group, greater recruitment in abductor halluces and greater fatigue in the tibialis anterior was observed. Individuals with flexible flatfoot showed altered muscle activation pattern after 6-min fast walking. These findings can provide an evidence-based explanation of associated syndromes in flatfoot populations and lead to potential intervention strategies in the future.

Highlights

Academic Editors: Alessandro de SireThe foot is constituted of 26 bones connected by multiple joints, ligaments, and tendons
Changes in muscle activation occur in different phases and different muscles; this includes a higher percentage of peak surface electromyography amplitude by the tibialis anterior in the contact phase and the tibialis posterior during propulsion, but a lower percentage on the peroneus longus throughout the stance phase [8]
Individuals with flexible flatfoot were distinguished from non-flatfoot individuals, using a navicular drop test, which is commonly used in clinical settings, as it can reveal the ability of the medial longitudinal arch (MLA) to act as a supportive structure

Summary

Introduction

Academic Editors: Alessandro de SireThe foot is constituted of 26 bones connected by multiple joints, ligaments, and tendons. Termed pes planus, is a postural deformity in which the arches of the foot collapse. Insufficiency, or rupture of the supporting structures of the medial longitudinal arch (MLA) [2]. Individuals with flatfoot require more muscle action than non-flatfooted people to support and propel the weight of their bodies due to instability in foot structure [7]. Changes in muscle activation occur in different phases and different muscles; this includes a higher percentage of peak surface electromyography (sEMG) amplitude by the tibialis anterior in the contact phase and the tibialis posterior during propulsion, but a lower percentage on the peroneus longus throughout the stance phase [8]. Individuals with flatfoot show higher tibialis anterior activity and lower activity in the peronei, soleus, and gastrocnemius in early stance relative to the mean stance phase [9]

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