Muscle synergies are consistent when pedaling under different biomechanical demands.
In this study we investigate the muscle coordination underlying the execution of a pedaling exercise across different biomechanical demands, by using the muscle synergies paradigm. 9 non professional subjects performed a cycling exercise using their preferred pedaling strategy (Preferred Strategy, PS) and then, through the use of a feedback based on the presentation of a real-time index of mechanical efficiency determined by means of instrumented pedals, they were helped to optimize their pedaling technique (Effective Strategy, ES). EMG activity was recorded from 8 muscles of the dominant leg. Nonnegative Matrix Factorization was applied for the extraction of muscle synergies. 4 modules were sufficient to reconstruct the repertoire of muscle activations for all the subjects during PS condition, and these modules were found consistent across all the subjects (correlation > 83%). 5 muscle synergies were necessary for the characterization in ES condition; 4 out of these modules were shared with PS condition, and the resulting additional module appeared subject-specific. These preliminary results support the existence of a modular motor control in humans.
Department of Applied Electronics, University Roma Tre,Rome, Italy. cdemarchis@uniroma3.it
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De Marchis
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Castronovo
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Bibbo
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Schmid
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Conforto
D000328:Adult; D001642:Bicycling; D001696:Biomechanical Phenomena; D004576:Electromyography; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*