Between-subject variability of muscle synergies during a complex motor skill

摘要: The purpose of the present study was to determine whether subjects who have learned a complex motor skill exhibit similar neuromuscular control strategies. We studied population experienced gymnasts during backward giant swings on high bar. This cyclic movement is interesting because it requires learning, as untrained are unable perform this task. Nine were tested. Both kinematics and electromyographic (EMG) patterns 12 upper-limb trunk muscles recorded. Muscle synergies extracted by non-negative matrix factorization (NMF), providing two components: muscle synergy vectors activation coefficients. First, coefficient correlation (r) circular cross-correlation (rmax) calculated assess similarities in mechanical patterns, EMG between gymnasts. performed further analysis verify that (in terms or coefficients) for one gymnast accounted other Three explained 89.9 ± 2.0% variance (VAF). coefficients among participants 0.83 0.08, 0.86 0.09, 0.66 0.28 #1, #2, #3, respectively. By keeping constant, we obtained an averaged VAF across all pairwise comparisons 79 4%. For coefficients, rmax-values 0.96 0.03, 0.92 0.95 72 5%. Although variability found (especially #3), exhibited gross strategies when performing swings. confirms consistent participants, even skilled task learning.