Normative Extensor Hallucis Brevis Muscle Activity During Locomotion Following the Development of a Novel...

Area of Science:

• Biomechanics
• Neuroscience
• Musculoskeletal Research

Background:

• Fine-wire electromyography (EMG) is a standard laboratory method for assessing small foot muscle activity.
• Recordings from the extensor hallucis brevis (EHB), a key great toe extensor, are currently lacking.
• EHB is crucial for understanding foot pathologies like hallux valgus.

Purpose of the Study:

• To establish an ultrasound-guided fine-wire EMG protocol for EHB muscle activity.
• To document normative EMG profiles of healthy young adults during walking.
• To investigate the functional role of EHB in locomotion and foot biomechanics.

Main Methods:

• Developed an ultrasound-guided fine-wire EMG protocol for EHB.
• Recruited 16 healthy young adults for walking trials at self-selected speeds.
• Calculated ensemble averages from time-normalized linear envelopes during the stance phase of gait.

Main Results:

• EHB muscle activity bursts were consistently observed from 0% to 20% of the stance phase.
• A secondary EHB burst occurred between 80% and 100% of stance in 50% of participants.
• Established normative EMG data for EHB during gait.

Conclusions:

• Introduced a novel ultrasound-guided EMG protocol for EHB.
• Normative EHB data suggest a synergistic role with anterior compartment muscles during foot contact.
• Findings offer insights into EHB function and biomechanical factors in hallux pathologies.