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Europa Medicophysica 2001 March;37(1):57-68

Copyright © 2001 EDIZIONI MINERVA MEDICA

language: English

Surface electromyography. A window on the muscle, a glimpse on the central nervous system

Merletti R., Farina D. *, Gazzoni M., Merlo A., Ossola P., Rainoldi A. **

From the Centro di Bioingegneria Laboratorio di Ingegneria del Sistema Neuromuscolare Politecnico di Torino e ASL 1, Regione Piemonte, Torino *Départment d’Automatique et Informatique Appliquèe Ecole Central de Nantes, Nantes, France **Department of Physical Medicine and Rehabilitation Università di Tor Vergata, Roma and Fondazione Don Carlo Gnocchi, Roma

This ­work pro­vides an over­view of the ­state of the art in the ­field of sur­face EMG for non inva­sive char­ac­ter­iza­tion of mus­cles and iden­tifi­ca­tion of CNS mus­cle con­trol strat­e­gies: it is in ­part a tuto­ri­al and in ­part a ­review. The mech­a­nisms of EMG sig­nal gen­er­a­tion, prop­a­ga­tion, detec­tion, pro­cess­ing and inter­pre­ta­tion are brief­ly sum­mar­ized. The ­main ­results of the European Concerted Action “Surface EMG for Non Invasive Assessment of Muscles” (SEN­I­AM) are out­lined. Specific atten­tion is ­focused on the key ­issue of prop­er elec­trode loca­tion ­over the mus­cle, ­that is in ­between the inner­va­tion ­zone and the mus­cle ten­don junc­tion. The infor­ma­tion con­tent of mul­ti­chan­nel EMG ­obtained ­with an elec­trode ­array is ­described and the con­cept of ­motor ­unit (MU) sig­na­ture is ­explained. The rec­og­ni­tion and clas­sifi­ca­tion of MU sig­na­tures dur­ing an iso­met­ric con­trac­tion strong­ly sup­ports the pos­sibil­ity of sur­face EMG decom­po­si­tion ­into the con­stit­u­ent (super­fi­cial) ­motor ­unit ­action poten­tial ­trains: exam­ples are giv­en. Applications for mon­i­tor­ing myoe­lec­tric man­i­fes­ta­tions of mus­cle ­fatigue are pre­sent­ed as ­well as appli­ca­tions in ­gait anal­y­sis. Most appli­ca­tions of the tech­nique are ­very “­treacherous” and ­require spe­cif­ic com­pe­tence and knowl­edge. The incor­rect modal­ities of ­data col­lec­tion and inter­pre­ta­tion are out­lined.