Corticomuscular interactions during different movement periods in a multi-joint compound movement

Area of Science:

• Neuroscience
• Motor Control
• Biomedical Engineering

Background:

• Understanding brain-muscle communication is crucial for motor control research.
• Compound movements, like the bipedal squat, involve complex neural coordination.
• Previous studies have primarily focused on simple movements, leaving compound movement control less explored.

Purpose of the Study:

• To investigate brain-muscle interactions during different phases of a bipedal squat (BpS) task.
• To analyze frequency-specific corticomuscular coherence (CMC) and partial directed coherence (PDC).
• To determine the direction of information flow between the brain and muscles during compound movements.

Main Methods:

• Participants performed 40 bipedal squats, divided into eccentric (ECC), isometric (ISO), and concentric (CON) phases.
• Electroencephalography (EEG) was recorded from 32 channels over sensorimotor areas.
• Electromyography (EMG) was recorded from four key muscles involved in the squat.

Main Results:

• Significant corticomuscular coherence and partial directed coherence were observed in beta and gamma frequency bands during the bipedal squat.
• Corticomuscular coherence was significantly higher during the eccentric and concentric phases compared to the isometric phase.
• The direction of information flow differed between movement phases, predominantly from EEG to EMG during concentric and EMG to EEG during eccentric phases.

Conclusions:

• Motor control during compound movements like the bipedal squat involves intricate brain-muscle communication across multiple frequency bands.
• Central motor commands are modulated by directed neural inputs, contributing to effective movement execution.
• This research provides novel insights into brain-muscle relationships during complex, multi-joint movements.