Article

A thorough understanding of the functional aspects of ankle joint control is
essential to developing effective injury prevention. It is of special interest to
understand how neuromuscular control mechanisms and mechanical constraints
stabilize the ankle joint. Therefore, the aim of the present study was to
determine how expecting ankle tilts and the application of an ankle brace
influence ankle joint control when imitating the ankle sprain mechanism during
walking. Ankle kinematics and muscle activity were assessed in 17 healthy men.
During gait rapid perturbations were applied using a trapdoor (tilting with 24
degrees inversion and 15 degrees plantarflexion). The subjects either knew that a
perturbation would definitely occur (expected tilts) or there was only the
possibility that a perturbation would occur (potential tilts).
Both conditions
were conducted with and without a semi-rigid ankle brace. Expecting perturbations
led to an increased ankle eversion at foot contact, which was mediated by an
altered muscle preactivation pattern. Moreover, the maximal inversion angle (-7%)
and velocity (-4%), as well as the reactive muscle response were significantly
reduced when the perturbation was expected. While wearing an ankle brace did not
influence muscle preactivation nor the ankle kinematics before ground contact, it
significantly reduced the maximal ankle inversion angle (-14%)
and velocity
(-11%) as well as reactive neuromuscular responses.
The present findings reveal
that expecting ankle inversion modifies neuromuscular joint control prior to
landing. Although such motor control strategies are weaker in their magnitude
compared with braces, they seem to assist ankle joint stabilization in a
close-to-injury situation.
CI - Copyright (c) 2013 Elsevier B.V. All rights reserved.

Langue : ANGLAIS