Human-Robot Interaction: Does Robotic Guidance Force Affect Gait-Related Brain Dynamics during Robot-Assisted...

Area of Science:

• Neuroscience
• Robotics
• Biomechanics

Background:

• Robot-assisted gait training is a promising rehabilitation strategy.
• Understanding the impact of robotic assistance on neural control is crucial for optimizing training parameters.
• Cortical activity reflects sensorimotor engagement during locomotion.

Purpose of the Study:

• To investigate the effect of varying guidance force levels from the Lokomat robotic gait orthosis on cortical activity during treadmill walking.
• To determine optimal robot-assisted treadmill walking parameters for maximizing sensorimotor cortex engagement.

Main Methods:

• Eighteen healthy subjects walked on a treadmill with and without the Lokomat robotic gait orthosis.
• Cortical activity was measured using electroencephalography (EEG) during unassisted and robot-assisted walking at 30%, 60%, and 100% guidance force.
• Event-related spectral perturbations and power spectral density were analyzed in sensorimotor cortex regions.

Main Results:

• Three clusters of gait-related spectral modulations (mu, beta, low gamma bands) were identified in the sensorimotor cortex.
• Cortical activity was significantly higher during unassisted treadmill walking compared to robot-assisted walking at 100% guidance force.
• Minimal differences in spectral power were observed between different levels of robot-assisted guidance force.

Conclusions:

• High guidance force (100%) in robot-assisted treadmill walking reduces sensorimotor cortex involvement.
• Minimizing robotic assistance promotes greater cortical engagement, which is essential for motor learning.
• Training parameters should be adjusted to encourage active participation during robot-assisted locomotion.