Article

In previous studies, it was found using cross-correlation analysis that the
modulation of the motor command to the calf muscles largely precedes body sway
during quiet standing. The purpose of this study was to investigate whether this
preceding time is correlated with an improved stabilization of the body. 26 young
and 23 elderly healthy subjects were asked to stand quietly. Body sway was
measured using a laser displacement sensor, and the electromyogram of the right
soleus was measured as a representative of the motor command. The correlation and
the time shift between motor command and body sway were estimated by means of
cross-correlation analysis. We found that sway size was correlated with the
identified time shift: that is, a smaller sway size was associated with a longer
preceding time. The obtained results suggest that a control strategy generating a
larger preceding time can stabilize the body more effectively. This result was
found in both the young and elderly, suggesting that the particular control
aspect associated with the time shift is a common feature in both age groups.
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Langue : ANGLAIS