Article

Loss of postural center-of-pressure complexity (COP complexity) has been
associated with reduced adaptability that accompanies disease and aging. The aim
of this study was to identify if COP complexity is reduced:
(1) in those with
Multiple Sclerosis (MS) compared to controls; (2) when vision is limited compared
to remaining intact; and (3) during more demanding postural conditions compared
to quiet standing. Additionally, we explored the relationship between the COP
complexity and disease severity, fatigue, cutaneous sensation and central motor
drive. Twelve women with MS and 12 age-matched controls were tested under quiet
standing and postural maximal lean conditions with normal and limited vision. The
key dependent variable was the complexity index (CI) of the center of pressure.
We observed a lower CI in the MS group compared to controls in both
anterior-posterior (AP) and medio-lateral (ML) directions
(p's<0.002), during the
performance of maximal self-regulated leans (AP: p<0.001; ML: p=0.018), and under
limited vision (AP: p=0.001; ML: p=0.006). No group-by-vision interaction
(p>0.05) was observed, indicating that limiting vision did not impact COP
complexity differently in the two groups. Decreased cutaneous sensitivity was
associated with lower CI values in the AP direction among those with MS
(r(2)=0.57); all other measures did not exhibit significant relationships. The
findings reported here suggest that (1) MS is associated with diminished COP
complexity under both normal and challenging postures, and
(2) complexity is
strongly correlated with cutaneous sensitivity, suggesting the unique
contribution of impaired somatosensation on postural control deficits in persons
with MS.
CI - Copyright (c) 2015 Elsevier B.V. All rights reserved.

Langue : ANGLAIS