Article

Plantar cutaneous afferent provides information about the contact between the
body and the support surface and could affect the anticipatory postural
adjustments (APAs). This study investigated the effect of plantar desensitization
on the APAs for step initiation. Twenty-five healthy young adults participated in
this study and were instructed to begin walking as fast as possible under 4
plantar desensitization conditions, none (NoneD), and desensitization of the
stepping, supporting or bilateral (BilD) plantar surfaces, with eyes open or
closed. The desensitization was achieved by cold water immersion of the plantar
surface for 15 min. Foot switches recorded the timing of the stepping events.
Surface electromyography (EMG) recorded the activation of bilateral tibialis
anterior. The center of pressure (COP) and ground reaction force (GRF) data were
derived from the force platform on which the subject initiated walking. The
results showed that during the anticipation phase, the peak COP displacement
toward the stepping leg was significantly smaller in BilD than in unilateral
desensitization, which in turn was smaller than in NoneD, regardless of vision.
The time to reach the peak COP displacement was significantly sooner with plantar
desensitization in the eyes open condition. The GRF, EMG and anteroposterior COP
displacement or the timing of the stepping events was not affected by plantar
desensitization. These findings indicate that plantar cutaneous afferent
contributed to the control of the APAs for step initiation by scaling the
displacement of the mediolateral COP displacement and loss of its sensitivity
could not be compensated by visual inputs.
CI - Copyright (c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS