The measures will include reaction and movement times, as well as the angular displacements of the relevant joints and the bilateral EMG activity of the distal and proximal muscles of the limbs. The spatio-temporal characteristics of the patients' movements will be analyzed using the recorded chronometric, kinematics and EMG data, and compared to those of age-matched control subjects. Muscle activity and movement will be recorded at the different levels of the moving and contralateral limbs to thoroughly monitor of the overflow characteristics of dystonia.