Muscular activity and physical interaction forces during lower limb exoskeleton use.

Area of Science:

• Robotics
• Neurorehabilitation
• Biomechanics

Background:

• Spinal cord injury (SCI) often results in lower limb sensorimotor deficits.
• Robotic exoskeletons offer a promising alternative to wheelchair reliance for SCI patients.
• Interaction forces between exoskeletons and users are a critical consideration.

Purpose of the Study:

• To investigate the origins of interaction forces in robotic exoskeletons for SCI patients.
• To differentiate between forces generated by exoskeleton movement and user muscular activity (EMG).

Main Methods:

• Utilized a similar experimental protocol to previous studies.
• Incorporated electromyography (EMG) analysis to measure muscle activity.
• Correlated force data with EMG signals during exoskeleton use.

Main Results:

• Peak interaction forces were observed primarily at the anterior right leg.
• Peak forces generally preceded peak EMG activity.
• A low correlation was found between overall EMG activity and force data, suggesting exoskeleton movement as the primary source of forces.
• Higher correlation coefficients were noted in muscle/force pairs at the anterior right leg, indicating a greater contribution from muscular activity in this specific region.

Conclusions:

• Interaction forces in robotic exoskeletons are largely attributable to the exoskeleton's movement.
• User muscular activity contributes more significantly to forces at the anterior right leg.
• Findings are crucial for developing intuitive control schemas for incomplete SCI patients using EMG feedback.