Ankle-foot orthoses: effect on energy expenditure of gait in spastic diplegic children.

This study examined the effect of conventional plastic bilateral ankle-foot orthoses (AFOs) on the energy expenditure of ambulation in spastic diplegic cerebral palsy patients. Eighteen subjects (aged 8.3 +/- 2.83 years) ambulated five minutes at freely chosen velocities with and without their AFOs. Heart rate (beats per minute) and distance (meters) ambulated were recorded for each minute. A physiologic cost index was calculated by determining the ratio of walking heart rate to velocity [(HRamb-HRrest) divided by meters per minute]. The mean physiologic cost indexes for the last three minutes of ambulation with and without orthoses were 1.34 +/- 0.69 beats per meter and 1.51 +/- 0.79 beats per meter, respectively (p less than 0.05). Ambulation heart rate, velocity and total distance traveled were not statistically different between the two trials. The results indicated that energy expenditure of ambulation at self-selected speeds in spastic diplegic children was reduced by the application of conventional AFOs. However, each child should be evaluated on a single-case basis because of individual differences.