Polyphasic potentials are abnormal electrical configurations of a motor unit and can be identified following axonal injury. Two types of polyphasic potentials can form following axonal degeneration: (1) nascent potentials (Fig. 1a) and (2) motor units formed from terminal collateral sprouting (Fig.

What is polyphasic of waveform?

Polyphasic - bidirectional wave with three or more phases in bursts.

What happens if EMG is abnormal?

An abnormal EMG result will present a bizarre pattern, with strange wave shapes. There is electrical activity even while at rest, and the electrical activity (produced by motor neurons) is abnormal during contraction of a muscle. Abnormal results indicate nerve dysfunction, muscle injury, or muscle disorders.