[Strategies for simultaneous control of the equilibrium and of the head position during the raising movement of a leg].
The coordination between equilibrium control and the ability to maintain the position of given segments (head, trunk) was studied in standing subjects, instructed to raise one leg laterally at an angle of 45 degrees in response to a light. Two sources of light placed at eye level indicated the side on which the movement was to be performed. Two populations were compared: naive subjects and dancers. Two control strategies were identified. An "inclination" strategy was used by the naive subjects. This consisted of an external rotation of the body around the antero-posterior ankle joint axis; a counter-rotation of the head with respect to the trunk was observed, which ensured some stabilization in the horizontal plane of the interorbital line. A "translation" strategy was used by the dancers. Here the external rotation of the leg around the ankle joint was associated with a feed-forward counter-rotation of the trunk around the coxofemoral joint so that the horizontality of the interorbital line and the verticality of the trunk axis were maintained. This new coordination results from a long-term training and indicates that a new motor program has been elaborated.
Mouchnino
L
L
Laboratoire de Neurosciences fonctionnelles, C.N.R.S., Marseille.
Aurenty
R
R
Massion
J
J
Pedotti
A
A
D000328:Adult; D003615:Dancing; D005260:Female; D006257:Head / Q000502:physiology*; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*
Stratégies de contrôle simultané de l'équilibre et de la position de la tête pendant l'élévation d'une jambe.