Excitation-contraction latency in the muscles of children and adults.

Excitation-contraction latency in the fast flexor carpi ulnaris and in the slow triceps surae muscles was studied in healthy children aged one month, 10 months and three years, and in adults. The tests were carried out during isometric twitch following supramaximal indirect stimulation. Excitation-contraction latency was found to increase with age in both the fast and slow muscles. The latency is longer for the slow than the fast muscle. A positive correlation was found in the children between excitation-contraction latency and contraction time.