Exoskeletons are mechatronic systems worn by a person in such a way that the physical interface permits a direct transfer of mechanical power and exchange of information. These robotic mechanisms have been applied in telemanipulation, man-amplifier, rehabilitation and to assist impaired human motor control. In addition, the neuromotor control research can benefit from a exoskeleton in order to manipulate human arm movements within its natural workspace, which is not possible with traditional robotic manipulandum because of its constraints. The aim of this paper is to describe a set of experiments in motor control and the application of powered upper limb exoskeleton in which the mechanical requirements of the movement will be modified, e.g. removal of the interaction torques in order to identify their impact on the production of complex coordination patterns in healthy subjects with the possibility for a future application to neurologically impaired subjects. As preliminary results, are shown responses to changes in viscosity and inertia when external perturbations (viscous load and inertia) are applied during execution of elbow angular cyclical movements using a robotic exoskeleton.