Surface EMC models: properties and applications

After a general introduction on the kind of models and the use of models in the natural sciences, the main body of this paper reviews potential proper ties of structure based surface EMG (sEMG) models. The specific peculiariti es of the categories (i) source description, (ii) motor unit structure, (ii i) volume conduction, (iv) recording configurations and (v) recruitment and firing behaviour are discussed. For a specific goal, not all aspects conce ivable have to be part of a model description. Therefore, finally an attemp t is made to integrate the 'question level' and the 'model property level' in a matrix providing direction to the development and application of sEMG models with different characteristics and varying complexity. From this ove rview it appears that the least complex are models describing how the morph ological muscle features are reflected in multi-channel EMG measurements. T he most challenging questions in terms of model complexity are related to s upporting the diagnosis of neuromuscular disorders. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.