title: Effect of electrode location on surface electromyography changes due to eccentric elbow flexor exercise.
abstract: Experiments were carried out to determine whether the location of electrodes has an effect on eccentric exercise-induced changes in surface electromyography (sEMG) variables in the biceps brachii muscle. sEMG signals were recorded with a grid of 64 electrodes before and up to 4 days post-exercise. Root mean square (RMS) and mean power frequency (MNF) were calculated for: (1) each channel; (2) as an average of all channels; and (3) as an average of individual channel rows and columns. Mean muscle-fiber conduction velocity (CV) was estimated similarly but was based on double-differential channels. Maximal isometric voluntary torque decreased 21.3 +/- 5.6% post-exercise. The average sEMG variables decreased after the exercise and recovered 2 days (RMS and CV) or 4 days (MNF) post-exercise. Site-dependent changes were observed in sEMG variables. We conclude that site-dependent changes in sEMG variables after eccentric exercise can be detected and are influenced in part by anatomical factors.
authors.affiliation: Neuromuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, P.O. Box 35, FIN-40014 Jyväskylä, Finland. harri.piitulainen@sport.jyu.fi
authors.forename: Harri
authors.initials: H
authors.lastname: Piitulainen
authors.forename: Reijo
authors.initials: R
authors.lastname: Bottas
authors.forename: Vesa
authors.initials: V
authors.lastname: Linnamo
authors.forename: Paavo
authors.initials: P
authors.lastname: Komi
authors.forename: Janne
authors.initials: J
authors.lastname: Avela
mesh_terms: D000328:Adult; D004550:Elbow / Q000502:physiology*; D004566:Electrodes; D004576:Electromyography / Q000379:methods*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000502:physiology; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000166:cytology / Q000502:physiology*; D010146:Pain / Q000209:etiology; D012815:Signal Processing, Computer-Assisted