This study compared the differences in energy efficiency (energy cost) in children with myelomeningocele ambulating with either reciprocating gait orthoses (RGOs) or hip-knee-ankle-foot orthoses (HKAFOs). There were 15 children who ambulated with RGOs and 11 children braced and ambulating in HKAFOs. Velocity was measured in m/s, energy consumption was measured in mL/kg/min, and energy cost (energy consumption/velocity) was measured in mL/kg/m. Children in HKAFOs had a significantly higher energy consumption rate than children in RGOs. However, children who swing through in a HKAFO have a significantly faster velocity than children who ambulate with the RGO using a reciprocating pattern. The increased energy cost in the RGO group is influenced by their slower velocity, just as the decreased energy cost in the HKAFO group is influenced by their increased velocity. Therefore it appears that children in HKAFOs are more energy efficient than children in RGOs.