1. Electromyography has been found useful in studying the pattern of motor activity in normal and paretic muscles, particularly in poliomyelitis and peripheral-nerve injuries.
2. Degrees of spasticity, rigidity, and tremor may be measured semi-quantitatively by this method.
3. Information of diagnostic importance is obtained from patients with progressive muscle atrophy, Parkinson's disease, peripheral-nerve injuries, and hysteria.