MENTAL STRESS INFLUENCE ON MOVEMENT

Abstract

The main aim of this work is the analysis of movement alterations under mental stress conditions. The right leg extension movement of 8 seated subjects. in different load situations, in normal and mental stress conditions, was analyzed. The mental stress situation refers to a numerical countdown computed by the subject during the movement execution. The movement analysis was carried out using the ELITE system that provides for the.complete kinematic analysis of the movements, allowing the quantitative study of 3-D markers' trajectories, displacements, velocities and accelerations. The muscular activity of rectus femoris and vastus medialis, that are the most important muscles for the extensional movement, was controlled with the EMG analysis. Particularly the markers' position are shown in fig. 1 For each movement and muscular acquisition the maximal height (H,,,,,) reached by the ankle together its trajectory, velocity, and accelerations were computed. Besides the interval time between each mental count and the subsequent was recorded. Finally the EMG signals were analyzed. This experimental study shows that the mental stress situation limits the normal execution of movement. In fact Hmax decreases when load and mental stress increase.