Electromyography vs. Foot Pedal Force Assessment During High-G Centrifuge Qualification Testing

Area of Science:

• Aerospace Medicine
• Human Factors Engineering
• Physiology

Background:

• Traditional anti-G straining maneuver assessment relies on foot pedal force, which has limitations in capturing muscle engagement.
• Surface electromyography (EMG) presents a potential alternative for assessing muscle activity during high-G exposure.

Purpose of the Study:

• To evaluate surface electromyography (EMG) as a tool for assessing muscle engagement during anti-G straining maneuvers in centrifuge qualification.
• To compare EMG-derived muscle activation patterns with traditional foot pedal force measurements.

Main Methods:

• Nineteen aircrew trainees underwent centrifuge testing with concurrent EMG monitoring of lower limb and abdominal muscles.
• EMG data and pedal force measurements were collected during gradual and rapid onset runs at various G-levels.
• Correlation and timing differences between EMG signals and pedal forces were analyzed across different acceleration profiles.

Main Results:

• EMG-pedal force correlations were limited and dependent on the acceleration profile.
• Only the right vastus medialis showed consistent correlation with right pedal force across profiles.
• Duration analysis revealed discrepancies, with pedal force duration often exceeding muscle activation duration.
• Abdominal muscle activation was consistently lower than other muscle groups during high-G exposure.

Conclusions:

• EMG provides a more comprehensive assessment of the anti-G straining maneuver than pedal force alone.
• EMG can delineate muscle activation patterns and timing differences not detectable by conventional methods.
• Incorporating EMG into centrifuge qualification can improve assessment accuracy and inform targeted training interventions.