A Computational Model Approach to Cerebral Palsy Gait: Mechanical Work With and Without a Pediatric Posterior Walker

Cerebral palsy is a neuromuscular disorder affecting motor function and development caused by a lesion to the brain at or around the time of birth. If not given adequate care and treatment prior to adolescence, children may lose the ability to ambulate on their own and require a wheelchair for mobility. Treatment for individuals with cerebral palsy targets increasing time walking throughout the day to avoid muscular atrophy while minimizing excess energy usage often seen in pathologic gait. Posterior walkers are commonly recommended by clinicians to increase stability and posture during gait. The purpose of this thesis was to further our understanding of the use of posterior walkers in both normal gait and pathologic, cerebral-palsied gait.

This work developed a dynamic model of the entire body which incorporated the posterior walker interaction forces during the gait cycle. The model was used to compare baseline, unassisted gait to gait with a posterior walker in typically developed (TD) and cerebral palsy (CP) child populations. Children with CP benefited from the walker through improved torso stability and reduced mechanical work of the whole body, particularly in the lower body and torso. Increased upper body moments highlighted the cost of pulling the walker and the applied vertical loading for support in the CP group. The TD group and the less-effected subjects in the CP group were inhibited by the walker as they walked slower and with shorter strides in walker-assisted gait. The current design of posterior walkers requires manual propulsion of the walker to take advantage of the benefits associated with its use. The dynamic model provides the ability to perform simulations with an automated walker which could decrease the energy expense of pulling the walker while still providing necessary stability. The development of an automated walker could further aid the user by neutralizing the required forces to pull the walker.