title: Training-related changes in the EMG-moment relationship during isometric contractions: Further evidence of improved control of muscle activation in strength-trained men?
abstract: The possibility of using electromyography (EMG) to track muscle activity has raised the question of its relationship with the effort exerted by the muscles around the joints. However, the EMG-moment relationship is yet to be fully defined, and increasing knowledge of this topic could contribute to research in motor control and to the development of EMG-based algorithms and devices. With regards the training-related adaptations at the peripheral and central level, the present study investigated the effect of strength training on EMG-moment relationship. Our aim was to clarify its nature and gain further understanding of how morphological and neural factors may affect its form. The EMG-moment relationship was determined during knee flexion and extension isometric contractions performed by strength-trained male athletes and untrained male participants. The results showed that strength training induced linearity of the EMG-moment relationship concomitantly with enhanced maximum force production capacity and decreased co-activation of knee agonist-antagonist muscle pair. These results clarified discordant results regarding the linear or curved nature of the EMG-moment in isometric conditions and suggested that the remarkable linearity of the EMG-moment found in trained participants could indicate improved control of muscle activation.
authors.affiliation: Inserm, Imagerie cérébrale et handicaps neurologiques UMR 825, Toulouse, France; Université de Toulouse, UPS, Imagerie cérébrale et handicaps neurologiques UMR 825, Toulouse, France. Electronic address: david.amarantini@univ-tlse3.fr.
authors.forename: David
authors.initials: D
authors.lastname: Amarantini
authors.affiliation: Codamotion, Victoria Mills, Fowke Street, Rothley LE7 7PJ, UK. Electronic address: bertrand.bru@codamotion.com.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Bru
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D004576:Electromyography / Q000379:methods*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D055070:Resistance Training / Q000379:methods*; D055815:Young Adult
keywords: Agonist–antagonist co-activation; Knee; Long-term strength training; Muscle fibre dominance; Neural adaptations