Article

We developed a method to investigate feed-forward and feedback movement control
during a weight bearing visuomotor knee tracking task. We hypothesized that a
systematic increase in speed and resistance would show a linear decrease in
movement accuracy, while unexpected perturbations would induce a
velocity-dependent decrease in movement accuracy. We determined the effects of
manipulating the speed, resistance, and unexpected events on error during a
functional weight bearing task. Our long term objective is to benchmark
neuromuscular control performance across various groups based on age, injury,
disease, rehabilitation status, and/or training. Twenty-six healthy adults
between the ages of 19-45 participated in this study. The study involved a single
session using a custom designed apparatus to perform a single limb weight bearing
task under nine testing conditions: three movement speeds (0.2, 0.4, and 0.6Hz)
in combination with three levels of brake resistance (5%, 10%, and 15% of
individual's body weight). Individuals were to perform the task according to a
target with a fixed trajectory across all speeds, corresponding to a
approximately 0 (extension) to 30 degrees (flexion) of knee motion. An increase
in error occurred with speed (p<0.0001, effect size (eta2): eta2=0.50) and
resistance (p<0.0001, eta2=0.01). Likewise, during unexpected perturbations, the
ratio of perturbed/non-perturbed error increased with each increment in velocity
(p<0.0014, eta2=0.08), and resistance (p<0.0001, eta2=0.11). The hierarchical
framework of these measurements offers a standardized functional weight bearing
strategy to assess impaired neuro-muscular control and/or test the efficacy of
therapeutic rehabilitation interventions designed to influence neuromuscular
control of the knee.
CI - Copyright (c) 2016 Elsevier B.V. All rights reserved.

Langue : ANGLAIS