Electromyographic activity in fast and slow elbow extensors during a visually guided forelimb movement in cats.

Electromyographic activity was recorded in the elbow extensors lateral (LaT) and medial (MeT) triceps and the elbow flexor cleidobrachialis (CB), during a rapid target directed forelimb movement. LaT, which was usually inactive during quiet standing, became strongly active in relation to the movement, while the reverse pattern was observed in MeT. The results are considered in relation to the difference in composition of motor until types with fast motor units predominating in LaT and slow in MeT.