Article

We examined the time varying (dynamic) characteristics of center-of-pressure
(COP) fluctuations in a group of 14 preadolescent dancers and 16 age-matched
non-dancers. The task involved maintaining balance for 20s with eyes open or eyes
closed, and with or without performing an attention demanding cognitive task
(word memorization). The main finding was that the time-dependent structure of
the COP trajectories of dancers exhibited less regularity than that of
non-dancers, as evidenced by a higher sample entropy (decreased statistical
regularity). COP irregularity also increased during secondary task performance
but decreased during standing with eyes closed. The combined findings indicate
that the degree of attentional involvement in postural control - as reflected in
the COP dynamics - varies along an automaticity continuum, and is affected by
relatively stable subject characteristics (expertise) and more transient factors
related to the attentional requirements of the task at hand.

Langue : ANGLAIS