Human cortical, muscular, and kinematic gait adaptation with novel use of an ankle exoskeleton

Abstract

Abstract Walking with an exoskeleton is a complex task that requires human and machine integration. Previous studies focused on metabolic consumption, muscle activations, kinetic and kinematic changes, and adaption during exoskeleton-assisted walking. However, limited information is available on cortical changes and adaptations during walking with an exoskeleton. Our study aims to better understand human cortical responses and adaptation to walking with an ankle exoskeleton. We included healthy, novice users without prior exoskeleton experience and collected EEG (electroencephalography), EMG (electromyography), and full body motion capture while walking at a speed of 1.2m/s. When experiencing exoskeleton-assisted walking for the first time, subjects showed reduced joint range of motion and stride length along with increased step width, even while muscle activation was decreased. The cortical response also follows the decreased balance, showing theta power increase in the left prefrontal, right sensorimotor, and right somatosensory cortex. Over time, the results showed increased balance, greater reduction in muscle activity, and reduced cortical engagement while walking with exoskeleton assistance. Yet, we also observed adaptation to walking with exoskeleton frames over time. These findings could provide information to develop more effective and intuitive augmentation devices that are better able to integrate with human movements.