ELECTROMYOGRAPHIC ASSESSMENT OF FOOT INTRINSIC MUSCLES IN THERAPEUTIC EXERCISE. A SCOPING REVIEW

Abstract

Introduction

Intrinsic foot muscles (IFM) are essential for medial arch support and biomechanical stability, yet standardized electromyography (EMG) methodology remains underdeveloped. This scoping review synthesized existing literature to identify which IFM and EMG methods are most used during therapeutic exercises, aiming to map current practices and guide future research.

Methods

Scoping review. Original articles evaluating IFM activity via EMG during therapeutic exercise, published between January 2000 and December 2025, were searched in PubMed and Scopus databases following PRISMA-ScR guidelines. Key concepts extracted included muscles evaluated, exercise type, EMG acquisition system, and electrode placement across different contexts.

Results

From 121 initial records, 28 studies were included. The abductor hallucis (AbdH) was the dominant muscle evaluated (26/28 studies), due to its location and size. Short foot and toe-spread exercises were most frequently investigated (19/28 studies). Surface EMG in bipolar configuration (26/28 studies) with a 20 mm inter-electrode distance was the predominant methodology.

Conclusions

Based on these results, surface EMG of the AbdH during short foot and toe-spread exercises represents the dominant methodological paradigm. However, the standard 20 mm inter-electrode distance may be suboptimal for the densely packed IFM, raising crosstalk concerns. Future research should explore ultrasound-guided electrode placement and smaller inter-electrode distances (10 mm) to improve measurement precision.