• Contrary to a prevalent belief, the rebound phenomenon of Gordon Holmes is not a sign of cerebellar disease. It is elicited by having the patient attempt to move a limb against resistance. When the resistance is suddenly removed, the limb normally moves a short distance in the desired direction and then rebounds (jerks back in the opposite direction). Gordon Holmes pointed out that the rebound phenomenon is (1) present in normal limbs, (2) exaggerated in spastic limbs, and (3) absent in limbs affected by cerebellar disease. An awareness of Holmes's observations may be helpful in the diagnosis of both cerebellar disease and spasticity.