PROJECT SUMMARY/ABSTRACT
Walking ability is critically important for pediatric health, well-being, and independence. Children with cerebral
palsy (CP), the most prevalent cause of pediatric physical disability, often present an increasingly crouched gait
pattern throughout development that negatively impacts walking capacity. Despite efforts to manage crouch gait
surgically and with physical therapy, walking deficits frequently remain after treatment; around 50% of affected
individuals lose the ability to walk. The overarching goal of this research is to achieve lasting corrections in
walking ability in children with CP through the intelligent implementation of wearable assistance training at home
and in the community. To inform dosing and implementation guidelines necessary for the design of long-term
studies, data on the physiological responses to daily exoskeleton training over intermediate time-frames (e.g. 2
weeks) are needed. Therefore, the objectives of this project are to understand the progression of biomechanical
adaptation to exoskeleton assistance during continuous training, and to develop techniques that can be
implemented to produce targeted neuromuscular engagement. The central hypothesis is that daily walking with
powered extension assistance will improve the interaction between the neuromuscular system and exoskeleton
to enhance outcomes; moreover, leveraging bio-feedback to target volitional muscle activity will further improve
posture and motor learning. The first specific aim is to quantify how the daily use of an assistive exoskeleton
during a two-week training period affects gait biomechanics, neuromuscular control, and metabolic walking
economy in children with CP. Participants will walk with knee extension assistance during daily training for 2
weeks. Gait analysis, electromyography, and oxygen consumption data will be measured during walking with
and without exoskeleton assistance on days 1, 7, 14, and 1-week after training. It is hypothesized that reductions
in antagonist muscle activity will be coupled with improvements in dynamic posture and walking economy over
the course of the study during walking with assistance, and participants will exhibit improved muscle activity and
posture during unassisted walking on day 14 and 1-week follow-up. The second specific aim is to determine how
incorporating real-time postural feedback during exoskeleton-assisted gait training affects functional outcomes
and motor learning in children with CP. Auditory and visual feedback of stance- and swing-phase knee extension
will be provided in relation to tailored improvement goals as participants walk with assistance. Providing feedback
and incentivizing improvement during assisted walking is hypothesized to result in increased knee extension and
knee extensor muscle activity compared to assisted walking without feedback. The knowledge gained from this
proposal will provide insight into the capacity of motor learning in children with CP, and enhance the ability to
optimize the prescription of wearable assistance for treating crouch gait.