Comparing the Biomechanics of Crouch Gait in Children with Cerebral Palsy to that of Age-Matched Controls and Young Healthy Adults

Cerebral palsy (CP) results from an injury to the developing brain and commonly results in an abnormal gait pattern. Crouch gait is a common gait abnormality associated with CP. The aim of the presented study was to compare kinematics, kinetics and EMG data of CP children walking with a crouched gait with those of aged-matched healthy children and young healthy adults. Gait experiments were performed on two CP children. The main difference in the gait patterns of healthy children and young healthy adults appeared to be in late stance, just before toe off. Children exerted lower torques about the knee and ankle, and they also exerted lower forces on the ground. In crouch gait, the net extensor moment exerted about the hip increased during early stance, which may be due to an increase in the passive force exerted by the hamstrings. Prolonged activity of the biceps femoris and co-contraction with rectus femoris, together with activation of gastrocnemius in late swing, may explain the excessive knee flexion observed in these patients. Early onset of tibialis anterior in the CP patients may also contribute to the reduced amount of ankle plantarflexion observed in these patients.