Differences between surface EMG in male and female subjects evidenced by automatic analysis

Area of Science:

• Biomedical Engineering
• Neuroscience
• Human Physiology

Background:

• Surface electromyography (EMG) is a non-invasive technique to assess muscle electrical activity.
• Understanding sex-based differences in muscle activation is crucial for fields ranging from sports science to rehabilitation.

Purpose of the Study:

• To investigate sex-based differences in the electromyographic (EMG) signal characteristics during maximal voluntary and evoked contractions of the tibialis anterior muscle.
• To explore potential underlying mechanisms, including motor unit recruitment strategies and the influence of socio-cultural factors.

Main Methods:

• Surface EMG signals were recorded from 40 healthy volunteers (20 males, 20 females) during maximal voluntary contractions (Vc) and evoked contractions (Vm).
• Power density spectrum (PDS) analysis was performed on EMG signals from the tibialis anterior muscle.
• Analysis included RMS values and the percentage distribution of power across five frequency bands (5-15, 20-40, 45-70, 75-110, 115-160 Hz).

Main Results:

• No significant sex differences were observed in evoked contraction (Vm) values.
• Maximal voluntary contraction (Vc) values were significantly lower in females compared to males (P < 0.001).
• Significant differences in the percentage distribution of power across frequency bands were found between males and females (P < 0.001).

Conclusions:

• Sex-based differences in EMG power spectrum distribution suggest distinct motor unit recruitment strategies.
• These observed differences may be more attributable to socio-cultural factors than to inherent physiological sex differences.
• Further research is warranted to elucidate the interplay between physiological and socio-cultural influences on motor control.