Posturographic Characteristics of Eccentric, Isometric and Concentric Movements

Subjects will undergo Computerized Dynamic Posturography (CDP) testing using the modified Clinical Testing of Sensory Integration in Balance (mCTSIB) protocol: the subjects will be required to stand on a hard or compliant surface (a 4" tall foam cushion of known mechanical properties) in a comfortable posture, feet shoulder width, with eyes open or closed, head straight and arms to the side and free to move, gazing forward, and breathing normally. Subsequently, subjects will be asked to stand first on the right leg and then on the left leg, raising the other leg (flexing the hip about 45 degrees), bending (flexing) the knee 90 degrees, keeping the arms extended and moving them laterally (abduct shoulders to 45 degrees and extend both elbows) to help maintaining balance with eyes open. Finally, subjects will be asked to perform 10 repetition of the squatting movement, with the operator pacing them (telling them when to start and when to stop the movements). The results of the mCTSIB, combined with an initial physical and neurological examination will be used to classify the subjects into the healthy and non healthy group.