This paper addresses the development of an apparatus designed to evaluate clinically the presence of spasticity affecting the elbow. The biomechanical contributions due to the lever-arm muscles and to the gravity force are accounted for using software algorithms that express gravity force and lever arm as functions of the elbow angle and are able to provide information on the force exerted by the muscles at a known speed. The preliminary data indicate that the device can be applied easily in the clinical setting. Further studies are required to demonstrate conclusively the validity and reliability of this device in quantifying spasticity at the elbow.