hypometric

Hypometric is an adjective describing an undershoot or underestimation relative to a target or measurement. In motor control, hypometric movements end short of the intended endpoint; the error is called hypometria. It is the opposite of hypermetric (or hypermetria), where movements overshoot the target. Hypometria is commonly discussed in neurology and neuro-ophthalmology as a feature of dysmetria, frequently arising from cerebellar dysfunction or intoxication.

In limb movements, a person may undershoot reaching for a cup; in eye movements, saccades can be hypometric, landing short of the target. Hypometria may be seen with cerebellar lesions affecting calibration and scaling of movement amplitude and can accompany other signs such as tremor, ataxia, or gait disturbance; it can be unilateral or bilateral depending on lesion location. It can be transient in acute intoxication or fatigue and may improve with adaptation or rehabilitation.

In measurement or experimentation, hypometric can describe a tendency of an instrument, test, or estimation to systematically underestimate a true value or target, though the term is more commonly discussed in terms of bias or underestimation.

See also: dysmetria, hypermetria, cerebellum, ataxia, ocular motor abnormalities.