Paratonia

Paratonia or gegenhalten is defined as "a form of hypertonia with an involuntary variable resistance during passive movement." In other words, attempting to move the limb of a person with paratonia will result in that person involuntarily resisting the movement. The amount of resistance is determined by the speed of the movement: faster, more forceful movements will result in greater amounts of resistance. It is also present regardless of the direction of the movement.