par Bengoetxea, Ana 
;Dan, Bernard ;Leurs, Françoise ;Cebolla Alvarez, Ana Maria ;De Saedeleer, Caty ;Gillis, P.;Chéron, Guy
Référence Clinical neurophysiology, 121, 5, page (754-765)
Publication Publié, 2010-01
;Dan, Bernard ;Leurs, Françoise ;Cebolla Alvarez, Ana Maria ;De Saedeleer, Caty ;Gillis, P.;Chéron, Guy Référence Clinical neurophysiology, 121, 5, page (754-765)
Publication Publié, 2010-01
Article révisé par les pairs
| Résumé : | OBJECTIVE: To address the question of how the CNS generates muscle activation patterns for complex gestures, we have chosen to study a figure-eight movement. We hypothesized that the well defined rhythmic aspect of this figure will provide further insights into the temporal features of multi-muscular commands. METHODS: Subjects performed, as fast as possible, figure-eights initiated in the center of the figure with 4 different initial directions and 2 positions of the shoulder. We extracted the temporal modulation of the EMG patterns by calculating conjugate cross-correlation functions. RESULTS: (1) The muscular command was tuned with respect to the rotational direction of the figure-eight, (2) two sets of synergistic muscles acted in a reciprocal mode, and (3) these reciprocal commands presented an invariant temporal correlation with the spatial component of the velocity having the highest frequency. CONCLUSION: Our results suggest that the rhythmic features of certain drawing movements favor the partitioning of the muscles into synergistic groups acting in a reciprocal mode. The inclusion of an individual muscle in one group or the other takes into account the expected number of changes of direction in the movement as a whole. SIGNIFICANCE: Muscular temporal synergies may depend on the rhythmic features of the trajectory. |
