Effects of a single session of prolonged plantarflexor stretch on muscle activations during gait in spastic cerebral palsy

Abstract

Activations of the triceps surae (TS) and tibialis anterior (TA) muscles during gait were studied in children with spastic cerebral palsy (CP) immediately before and after 30 min of standing on a tilt-table with the ankle dorsiflexed to stretch the TS in the experimental group (n = 8) or after a rest period in the control group (n = 11). The EMG activity from the TS and TA was recorded concomitantly with electronic footswitch signals by a computer. Video records were made of the sagittal gait movements. Effects of PMS were determined by comparing change scores for selected spatiotemporal and muscle activation parameters between the groups. The change scores defined for the muscle activations were: a post-test/pre-test ratio of the EMG activity in specific segments of the gait cycle and a locomotor spasticity index. PMS did not significantly (p greater than 0.05) affect any of the spatiotemporal parameters nor did it alter any of the TS and most of the TA activation parameters or the SI indexes for the TS and TA. Only the TA post/pre activation ratio for the 0-16% segment of the gait cycle was smaller (p less than 0.01), indicating a decrease in TA activation post-PMS.