Direct effect of percutaneous electric stimulation during gait in children with hemiplegic cerebral palsy: a report of 2 cases

The feasibility of using percutaneous intramuscular functional electric stimulation (FES) in children with cerebral palsy (CP) as a method to improve ankle kinematics and kinetics during gait was investigated. Two children with right hemiplegic CP had percutaneous intramuscular electrodes implanted into the gastrocnemius and tibialis anterior muscles of the involved limb. FES was provided during the gait cycle using force-sensing foot switches to detect gait phase transitions. The children ambulated using FES under 3 conditions (gastrocnemius on, tibialis anterior on, gastrocnemius and tibialis anterior on). For each condition, two 45-minute walking sessions were conducted per day for 1 week. Immediately after each week of practice, a gait analysis was performed at the subject's self-selected walking speed for that stimulation condition and without stimulation. Both children demonstrated improvements in ankle dorsiflexion angle at initial contact, peak dorsiflexion during swing, mean dorsiflexion during swing, and ankle work during early stance with tibialis anterior stimulation alone and combined gastrocnemius and tibialis anterior stimulation. Improvements in ankle work were found during late stance for both children with all stimulation conditions. These results suggest that percutaneous intramuscular FES was effective in improving aspects of ankle kinematics and kinetics of 2 children with hemiplegic CP.