dysmetria /dismē″trē·ə/ [Gk, dys + metron, measure] , a condition that prevents the affected individual from properly measuring distances associated with muscular acts and from controlling muscular action. It is associated with cerebellar lesions and typically characterized by overestimating or underestimating the range of motion needed to place the limbs correctly during voluntary movement. A person without neurologic impairment and with eyes closed can move the arms from a position of 90 degrees of flexion to a position over the head and then return them to the 90-degree position; a person with dysmetria is unable to perform this test accurately. See also hypermetria, hypometria.
