Dynamic modulations of effective brain connectivity associated with postural instability during multi-joint compound...

Area of Science:

• Neuroscience
• Biomechanics
• Motor Control

Background:

• Somatosensory signal fluctuations impact coordinated movement and postural control.
• Understanding how unstable surfaces affect sensorimotor integration is crucial for optimizing performance and rehabilitation.

Purpose of the Study:

• To investigate the effect of a compliant surface on cortico-cortical causal information flow during multi-joint movements.
• To analyze changes in motor behavior and brain connectivity under different surface conditions.

Main Methods:

• Fifteen healthy adults performed bodyweight squats on firm and compliant surfaces.
• Motor behavior was assessed via center of pressure (CoP) displacement, hip motion, and rectus femoris activity.
• Effective brain connectivity was computed using source space analysis and renormalized partial directed coherence (rPDC) in theta and beta frequencies.

Main Results:

• The compliant surface resulted in decreased medio-lateral CoP displacement and rectus femoris activity, but increased hip motion velocity.
• Significantly modulated information flow was observed in fronto-parietal cortical connections during the concentric phase.
• Altered brain connectivity suggests modified sensorimotor processing demands on compliant surfaces.

Conclusions:

• Performing squats on compliant surfaces presents challenges for hip control and alters neural processing.
• Modulations in effective brain connectivity indicate adaptive sensorimotor strategies in response to increased sensory noise.
• Further research is warranted to explore benefits for athletic and clinical populations.