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 of velocity [(HR(amb) - HR(rest)) : meters per minute]. The mean physiologic cost indexes for the last three minutes of ambulation with and without orthose were 1.34 ± 0.69 beats per meter and 1.51 ± 0.79 beats per meter, respectively (p < 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.