Dorsiflexion Specific Ankle Robotics to Enhance Motor Learning After Stroke: A Preliminary Report

Area of Science:

• Biomedical Engineering
• Neurorehabilitation
• Robotics

Background:

• Hemiparetic gait and foot drop after stroke present significant mobility challenges.
• Locomotor learning and biomechanical adaptations are crucial for gait retraining but remain understudied.
• Ankle exoskeletons offer a promising approach for targeted gait rehabilitation.

Purpose of the Study:

• To investigate the effects of task-specific ankle robotics training on gait biomechanics and functional mobility in individuals with chronic hemiparetic gait and foot drop.
• To assess the biomechanical adaptations and motor learning that occur with robotic-assisted gait training.
• To evaluate the efficacy of the ankle exoskeleton (AMBLE) in improving gait parameters and functional outcomes.

Main Methods:

• A single-armed, non-controlled study involving 16 participants with chronic stroke and foot drop.
• Nine hours of task-specific ankle robotics training using the AMBLE exoskeleton over 9 weeks.
• Assessment of 3-D gait biomechanics using optical motion capture and functional mobility tests during unassisted walking.

Main Results:

• Significant improvements in kinematic parameters including ankle dorsiflexion velocity, foot strike patterns, and knee flexion.
• Enhanced temporal-spatial gait parameters such as increased step length and reduced swing duration.
• Notable functional gains in walking velocity, 6-minute walk distance, and Dynamic Gait Index scores, surpassing minimal clinically important differences.

Conclusions:

• Ankle robotics training (AMBLE) effectively improves neuromotor control of the paretic ankle and knee, leading to better gait parameters.
• Locomotor learning, evidenced by increased autonomous ankle control, translates to significant functional mobility improvements.
• Further large-scale randomized trials are warranted to confirm these findings and optimize robotic training protocols for hemiparetic gait.