Exoskeleton Assistance Improves Crouch during Overground Walking with Forearm Crutches: A Case Study.

Research, development and testing of wearable robotic exoskeletons for gait training and improved mobility in children with cerebral palsy (CP) and other movement disorders has become increasingly prevalent in recent years. Broadly, these devices are split into two categories: fully wearable devices that are affixed to the lower limbs and/or pelvis and systems that include a mobile frame that moves with the user. The former systems have generally targeted more functional individuals who are independent walkers while the latter target more affected individuals who do not ambulate on their own. The best strategy for children in the middle of this mobility spectrum (GMFCS III), who can walk short distances using assistive instruments like crutches or walkers, is not clear. Yet, these children may benefit most from gait training because they are at the highest risk to lose their independent mobility. Here, we present a case study of a wearable robotic exoskeleton for overground walking in a child with CP at GMFCS III. Our results demonstrate that the exoskeleton was able to synchronize assistance to five discrete phases of the gait cycle during overground walking with forearm crutches. Peak knee extension improved on average by 10 degrees in the right leg and 7 degrees in the left leg when walking with exoskeleton assistance during early stance, mid-stance and late swing without reduction in muscle activity. Therefore, state-based control for providing robotic extension assistance to individuals with crouch from CP who walk with assistive instruments should be further investigated as a potential rehabilitation strategy.