Article

Participants with ankle instability demonstrate more foot inversion during the
stance phase of gait than able-bodied subjects. Invertor excitation, coupled with
evertor inhibition may contribute to this potentially injurious position. The
purpose of this experiment was to examine evertor/invertor muscle activation and
foot COP trajectory during walking in participants with functional ankle
instability (FI). Twelve subjects were identified with FI and matched to healthy
controls. Tibialis anterior (TA) and peroneus longus (PL) electromyography (EMG),
as well as COP, were recorded during walking. Functional analyses were used to
detect differences between FI and control subjects with respect to normalized EMG
and COP trajectory during walking. Relative to matched controls, COP trajectory
was more laterally deviated in the FI group from 20% to 90% of the stance phase.
TA activation was greater in the FI group from 15% to 30% and 45% to 70% of
stance. PL activation was greater in the FI group at initial heel contact and toe
off and trended lower from 20% to 40% of stance in the FI group. Altered motor
strategies appear to contribute to COP deviations in FI participants and may
increase the susceptibility to repeated ankle inversion injury.
CI - Copyright A(c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS