Gait Neuromechanics

Sudden Ankle Inversion Perturbation During Walking Alters Gait Kinematics in Chronic Ankle Instability Patients.

Context: Individuals with chronic ankle instability (CAI) have demonstrated altered lower-extremity joint kinematics during walking. The purpose of this study was to examine feedback control of gait kinematics following repeated sudden ankle inversion perturbation during walking in CAI patients relative to matched controls. Methods: Twenty-one CAI patients, 21 matched controls participated. Subjects performed five walking trials at a preferred speed both before and after 10 sudden ankle inversion perturbations during walking while 3D joint kinematic data were collected using high-speed video and in-ground force plate. Main outcome measures were ankle- (sagittal and frontal planes), knee- (sagittal plane), and hip-angles (sagittal and frontal planes) from heel-strike to toe-off. Spatial trajectories of 44 markers were smoothed using a digital filter. Functional analysis was used to detect mean differences. Results: CAI group demonstrated (i) less ankle dorsiflexion, (ii) more ankle eversion, (iii) less knee flexion, (iv) less hip flexion, and (v) more adduction during walking trails, compared to the control group. The 10 sudden ankle inversion perturbations resulted in more ankle dorsiflexion only in the CAI group. However, both the CAI and control groups demonstrated no differences in frontal ankle, sagittal knee and sagittal and frontal hip kinematics between pre- and post-intervention measurements. Conclusions: Sudden ankle inversion perturbations did not affect gait kinematics in both CAI and control groups except sagittal ankle kinematics in the CAI group. Increased ankle dorsiflexion after inversion perturbation in the CAI group may be the result of a change in motor control to avoid self-perceived vulnerable positions of the foot during walking.
Listed In: Biomechanics, Gait