Simulation of EMG in pathological situations

Objective: A mathematical model for simulation of the EMG from a muscle wit h its motor units is used. The study aims at correlating EMG findings (sing le-fiber EMG and concentric-needle EMG) with various induced morphological changes. Methods: Reinnervation has been simulated by removing motor units randomly followed by a complete reinnervation from adjacent surviving motor units. F ibre type grouping and grouped atrophy can be seen. Myopathy is simulated b y increased fibre diameter variation, loss of fibres and muscle fibre split ting. Results and conclusion: The simulation gives quantitative aspects of the im portance of each of these factors. It indicates the relative sensitivity of various EMG parameters. The model can be used both for education and for r esearch. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.