[Electromyography as a diagnostic aid (author's transl)].

Electromyography reflects the anatomical situation in the muscle parenchyma. Changes in the anatomical structure are present if the normal potential form breaks up into small amplitude or even polyphasic potentials (myopathy type) or increases into high amplitude, broad and coarsely fragmented potentials (chronic neuropathy with regeneration). The caliber and type of muscle fibers are expressed in the speed of conduction. Spontaneous activity suggests an increased excitability of the muscel fibers. Disturbances of neuromuscular transmission are detectable by direct stimulation of the muscle. Analysis of nerve conductivity permits the demonstration of diffuse (polyneuropathy type) or circumscribed (entrapment neuropathy type) nerve affections. The recording of the parameters mentioned is the domain of EMG.