We assessed parkinsonian rigidity objectively at the wrist to determine the optimal angular velocity and displacement for detecting abnormality. The wrist was moved passively with a torque motor and the average work done for one complete cycle was computed. This objective rigidity score (ORS) was compared with a clinical rigidity score (CRS). ORS was more pronounced at faster movement velocities in parkinsonian patients, whereas in normal subjects there was only a modest increase in the score. Angular velocities of 140 to 190 degrees/second and displacements of +/- 25 to +/- 30 degrees were most sensitive for detecting parkinsonian rigidity and had good correlation with the CRS.