Corticomuscular Coupling Analysis of Dynamic Balance During Eccentric and Concentric Muscle Contractions

Area of Science:

• Neuroscience
• Biomechanics
• Human Movement Science

Background:

• Maintaining dynamic body balance is essential for daily activities.
• Balance involves complex interplay between eccentric and concentric muscle contractions.
• Neural mechanisms governing muscle contractions during dynamic balance are not fully understood.

Purpose of the Study:

• To investigate corticomuscular connectivity during dynamic balance tasks.
• To differentiate neural control during eccentric versus concentric muscle contractions.
• To explore the influence of balance difficulty on brain-muscle communication.

Main Methods:

• Collected electroencephalography (EEG) and electromyography (EMG) signals from 11 healthy males during a heel-lifting task.
• Utilized wavelet packet transfer entropy to analyze corticomuscular connectivity.
• Examined changes across different balance difficulties and muscle contraction types.

Main Results:

• Higher electroencephalography-electromyography coupling observed in the gamma band.
• Direction of information flow varied by frequency band (alpha/beta: brain-to-muscle; gamma: muscle-to-brain).
• Eccentric contractions showed stronger corticomuscular coupling, with greater muscle influence on the cortex, especially during lowering tasks and increased balance difficulty.

Conclusions:

• Dynamic balance relies on intricate corticomuscular interactions modulated by muscle contraction type and balance demands.
• Eccentric contractions involve a stronger feedback loop from muscles to the brain compared to concentric contractions.
• Findings provide insights into neural strategies for maintaining body stability.