[The plasticity of motor units in change of the activity pattern by electric stimulation--electrostimulation and its possible clinical applications].

Motoneuron and muscle fibers interact on the motor unit level, whereby discharge characteristics from the neuron imposed on the muscle seem to play a major role. Within the unit all muscle fibers are biochemically homogeneous and display a high degree of plasticity under different functional demands. To distinguish the existing different units rationals are listed that classify the units by physiological and histochemical parameters. Furthermore the review summarizes the available knowledge on the importance of activity patterns--as a biological principle--involved in the control of phenotypic expression of innervated and denervated muscle. The sequelae are shown of electrical stimulation on innervated and denervated animal muscles. In extent to these findings the consequences are discussed for stimulation procedures that can be imposed on normal and diseased human muscles as a therapeutic tool.