Muscle strengthening through electric stimulation combined with low-resistance weights in patients with neuromuscular...

Ten patients with gradually progressive neuromuscular disorders underwent (1) unilateral electric stimulation of anterior tibialis muscles and (2) unilateral stimulation of quadriceps femoris muscles, in combination with voluntary knee extension against ankle weights. After electric stimulation two hours/day, five days/week for two to 14 months, the mean maximum force (muscle strength) of knee extension increased significantly (p less than 0.005), by 108% +/- 56%. The contralateral nonexercised knee extensors also showed some increase in muscle strength. Electric stimulation of ankle dorsiflexors was ineffective; the maximum force of ankle dorsiflexion increased by only 11% +/- 27% (p greater than 0.3). In general, severely weak muscles (less than 10% normal strength) did not improve with either stimulation program. Electric neuromuscular stimulation combined with low-resistance weights can significantly increase muscle strength in patients with neuromuscular disorders if disease progression is gradual and initial muscle strength is greater than 15% normal.