Center of mass movement and energy transfer during walking in children with cerebral palsy

Objective: To gain insight into the mechanical inefficiencies of gait patterns used by children with spastic diplegia by analysis of center of mass (COM) movement and energy recovery. Design: Prospective study using between-group measures to analyze differences between children with cerebral palsy (CP) and age-matched controls without CP. Setting: Assessments were performed in a gait laboratory. Participants: Fifteen children with spastic diplegia and 6 age-matched controls without CP with a mean age of 9.7 years. Interventions: Not applicable. Main Outcome Measures: Gait data assessed included temporal-distance factors, COM vertical excursion, work done on the COM, and the percentage of energy transferred and relative phase between the potential and kinetic energy. Results: Children with CP had a 33% smaller energy recovery factor than the controls (P<.001). They also had 60% greater COM vertical excursion (P<.02) and a poorer phasic relation between potential and kinetic energies (P<.02), both of which contributed to greater mechanical work performed (P<.003). Conclusions: Compared with the age-matched controls without CP, the children with CP were mechanically less efficient in their gait. Interventions that promote heel contact and roll over and greater knee stability to better utilize the kinetic energy of push-off Could improve walking efficiency.