Neuromuscular activity and functional performance in individuals with chronic ankle instability, copers, and healthy individuals: HD-EMG complex data analysis

• Grant number: 25/13571-3
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: January 26, 2026
• End date: May 25, 2026
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Isabel de Camargo Neves Sacco
• Grantee: Milena Bürgel Murari Fernandes
• Supervisor: Eduardo Martinez-Valdes
• Host Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Birmingham, England
• Associated to the scholarship: 24/16019-7 - Investigation of the motor complexity and neuromuscular control through high density surface EMG in people with ankle chronic instability, BP.MS

Abstract

This study aims to investigate neuromuscular control and its relationship with functional performance in physically active individuals with and without chronic ankle instability (CAI), including both copers and non-copers. The goal is to explore differences in motor strategies, signal complexity, and force variability between these groups using surface high-density electromyography (HD-EMG) and na isometric dynamometry. Data collection is being conducted entirely at the Laboratory of Biomechanics of Human Movement and Posture (LaBiMPH) at the University of São Paulo (USP), and includes assessments of four lower limb muscles (tibialis anterior, peroneus longus, lateral and medial gastrocnemius) during three ankle movements: flexion with inversion, extension, and extension with eversion. Functional performance is evaluated using the Y-Balance Test and Side Hop Test. Signal processing and data analysis will take place during a four-month research internship at the University of Birmingham (UoB), under the supervision of Professor Eduardo Martínez-Valdés. The HD-EMG signals will be analyzed for root mean square (RMS), sample entropy, and muscle fiber conduction velocity (MFCV), while force signals will be evaluated for magnitude and variability using both linear and nonlinear methods. Mixed two-way ANOVAs will be used for statistical comparisons between groups, muscles, and task conditions. The internship will focus on applying advanced analytical techniques, with particular emphasis on complexity measures in EMG, estimation of muscle fiber conduction velocity, analysis of intermuscular connectivity, and activation strategies of ankle-stabilizing muscles during isometric tasks. The internship will focus on applying advanced analytical techniques to support the interpretation of neuromuscular complexity in CAI. Academically, the candidate will benefit from intensive training in HD-EMG signal processing, exposure to novel methodologies, and close collaboration with an internationally recognized research team. These experiences are expected to enhance the scientific rigor of the ongoing master's project, contribute to co-authored publications and strengthen international academic networking. (AU)