Effects of peripheral fatigue of ankle evertors on force sense and electromyographic activity in healthy subjects

Brezovar, Tjaž (author), Vene, Maja (author), Tučen, Taja (author), Jagarinec, Anika (author), Puh, Urška (author), Kacin, Alan (author)

Background: Ankle proprioception is essential for dynamic stability, but fatigue may impair force sense and neuromuscular control, increasing injury risk. Their relationship remains unclear. Objective: To examine the effects of ankle evertor fatigue on force sense accuracy and variability, along with associated changes in muscle activation. Methods: Twenty-four healthy participants completed a force-matching task in ankle eversion at 25% and 50% of MVIC before and after a fatigue protocol. Force sense was assessed by constant, absolute, and variable error and coefficient of variation. RMS amplitude was calculated for the peroneus longus, tibialis anterior, soleus, and gastrocnemius medialis, and median frequency only for the peroneus longus. Results: With fatigue, there was a 34.7% reduction in MVIC torque (p < 0.05). During force-matching tasks, variable error at 50% MVIC and coefficient of variation without visual feedback at 25% and 50% MVIC increased (p < 0.01), EMG amplitude of all muscles substantially increased (p < 0.05), and median frequency of the peroneus longus decreased (p < 0.001). Conclusion: Peripheral fatigue of ankle evertors increases variability in muscle force output, which is accompanied by compensatory motor unit recruitment during force matching, resulting in elevated variability.

• Language: English
• Keywords: episiotomy, external anal Sphincter, innervation zones, surface electromyography, fecal incontinence
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: ZF - Faculty of Health Sciences; MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Publication date: 01.01.2025
• Year: 2025
• Number of pages: 8 str.
• Numbering: Vol. 85, art. 103083
• PID: 20.500.12556/RUL-176814
• UDC: 615.82/.84
• ISSN on article: 1873-5711
• DOI: 10.1016/j.jelekin.2025.103083
• COBISS.SI-ID: 260941059
• Publication date in RUL: 11.12.2025

Record is a part of a journal

• Title: Journal of Electromyography and Kinesiology
• Publisher: Elsevier
• ISSN: 1873-5711
• COBISS.SI-ID: 23140613

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.