Surface Electromyographic Analysis of Soleus muscle activity in different shod conditions in Healthy Individuals – Systematic review

Abstract

Objective

Soleus is an effective plantar flexor that has distinct functional roles and behaves differently during different biomechanical actions. Different footwear types may give rise to adjusted muscular effort and biomechanics of Soleus muscle action. Consequent altered ground reaction forces created at the foot may give rise to injuries/fatigue during different activities. Relatively little is known about in vivo behavior of the Soleus muscle during walking and running. Surface Electromyography (SEMG) is commonly analyzed by researchers to understand lower limb muscle activity. The Objective of this study was to systematically review available research literature investigating Soleus SEMG activity in healthy subjects under different footwear conditions during different tasks.

Methods: electronic databases PUBMED, EBSCOHOST (Academic Elite) and SCIENCEDIRECT were searched on 30.11.2020 for the combination of keywords “Surface Electromyography” AND “Shoe” AND “Soleus”. Inclusion and exclusion criteria were specified in advance. The methodological quality of each relevant study was independently evaluated for “Risk of bias” on Modified Downs and Black checklist. Studies with quality score >50% were considered reasonable to be included in this review.

Results

Total 435 research publications were generated in search; 247 articles were excluded on the basis of initial title screening (including duplicates), 155 articles were excluded after Abstract and (or) full text screening, 33 studies were included for quality assessment. 15 studies were considered of reasonable quality (>50% score) to be selected for this review. Information was extracted from each selected study on: PICOT terms and Outcome Measures (SEMG activity) reported in each study.

Discussion

Results of the reviewed studies generally reported that, “Shoe conditions lead to different soleus activation patterns”, however there is weak to moderate evidence on difference in soleus muscle activity on SEMG under different footwear conditions. All studies involved highly variable features on PICO (terms) characteristics.

Conclusion

The clear effect of shoe on Soleus muscle activity is not fully understood; further research work especially investigating effect of footwear in non locomotor actions of soleus muscle in real life setting is recommended.