Hypometria is a reduction in the amplitude of voluntary movements. It may be demonstrated by asking a patient to make repeated, large amplitude, opposition movements of thumb and forefinger, or tapping movements of the foot on the floor. A gradual decline in amplitude (which may be referred to as fatigability; cf. fatigue) denotes hypometria. Voluntary saccadic eye movements may also show a "step", as a correcting additional saccade compensates for the undershoot (hypometria) of the original movement.
Hypometria is a feature of parkinsonian syndromes, such as idiopathic Parkinson’s disease.