The possibility of overall recording of the electrical activity generated by muscle fibres making up the motor unit in its entire territory, is the characteristic and main objective of macro-EMG studies. This is possible because of the technical characteristics of the electrode and the recording conditions whose methodology is described. We describe how parameters of macro-EMG are obtained in normal healthy people, and define changes in parameters in pathological neurogenic and myogenic disorders and their value in the follow-up of reinnervation processes.