Effect of ankle foot orthosis on energy expenditure index and gait speed in spastic cerebral palsy children: an observational study

Background: Ankle Foot Orthosis (AFO) is a frequently prescribed intervention modality which plays an important role in the management of gait abnormality. The most typical use of AFOs is to optimize the normal dynamics of walking by applying mechanical constraint to the ankle to control motion & at the same time provide more efficient gait. Solid AFOs are most commonly prescribed to reduce excessive plantar flexion in stance & to prevent or eliminate equinus position. So, purpose of this study is to determine whether use of AFO affect the gait speed & energy expenditure in cerebral palsy children or not. Methods: a convenient sample of 21 subjects diagnosed with spastic cerebral palsy with presence of spasticity of planter flexors (Modified Ashworth Scale < 3) with GMFCS level 1, 2 & 3 were included. Informed consent of parents was taken. Children who had undergone surgical correction within 6 month of testing or botulinum toxin injection of spastic planter flexors or any other lower extremity muscle within 3 months were excluded. For 10 meter walk test child was made to walk barefooted then given 10 minute rest & made to walk again for 10 meters with AFO. Their heart rate (Resting & after walking) & time taken for walk were taken each time & energy expenditure index (walking HR-resting HR/distance) & gait speed (distance/time) were calculated. Results: Mean Energy Expenditure Index (EEI) with barefoot was 158.8 ± 2.37 & with AFO was 370.4 ± 3.93. Speed with barefoot was 0.22 ± 0.16 & with AFO was 0.148 ± 0.18. There was significant difference in gait speed & EEI between the groups & P value was < 0.05. Conclusion: There is increase in EEI & decrease in gait speed in children with spastic cerebral palsy with the use of AFO.