The effect of surface and internal electrodes on the gait of children with cerebral palsy, spastic diplegic type

Abstract

The purpose of this study was to determine whether surface and internal fine‐wire electromyography electrodes had an effect on gait. The subjects for the experiments were 38 children with the spastic diplegic type of cerebral palsy. The children were filmed using the high‐speed cinematographic technique while they walked (a) with no electrodes (unencumbered), (b) with only surface electrodes, and (c) with internal electrodes. Single stance time, step length, cadence, and walking velocity were compared with analysis of variance and Bonferroni t tests. The results included a significant decrease in cadence (−6.3% of unencumbered walking; p < 0.05) when comparing walking with surface electrodes with walking without any electrodes. The internal electrodes caused significant decreases from normal walking in the following parameters: step length for both the measured leg ( −18.6%; p < 0.005) and the nonmeasured leg ( −18.0%; p < 0.005), cadence ( −7.9%; p < 0.02), and walking velocity ( −23.5%; p < 0.005). Internal electrodes caused significant decreases as compared with surface electrodes in the step length for both the measured leg (15.7%; p < 0.01) and the nonmeasured leg (15.6%; p < 0.005) and walking velocity (19.7%; p < 0.005). Single stance phase did not change significantly in any of the comparisons. It appears that the addition of the surface electrode apparatus does change the normal gait of a subject, causing a large decrease in cadence. The measurement of gait with internal electrodes causes further change in gait, resulting in large decreases in step length and walking velocity. While these tests provide important and useful clinical data, physicians and researchers must realize that the gait being measured with these techniques is different from a normal gait pattern.