Long-term electrical stimulation of muscles in children with Duchenne and Becker muscular dystrophy

Nine children suffering from progressive muscular dystrophy (7 Duchenne and 2 Becker) were included in a program of low-frequency electrical stimulation (LFES) of the right tibialis anterior (TA) muscle. Muscle strength and muscle fatigue were estimated by measuring torques in the ankle during attempts of maximal voluntary contraction (MVC) in the direction of dorsal flexion of the foot and during electrically evoked contractions (EEC). No important increase in the strength of the stimulated muscles was noticed in 4 boys whose muscles were stimulated for 3 months. The muscles of 5 boys who were subjected to electrical stimulation for 9 months showed an improvement; 6 measurements made during the stimulation program revealed that changes of torques in the ankle of the right stimulated extremity were significantly different (P less than 0.001) from the changes of torques in the ankle of the left nonstimulated extremity.