Dysmetria can result in moving beyond the target (hypermetria) or failing to reach the target (hypometria) during a voluntary movement. Dysmetria can be assessed clinically by the finger chase test, whereby the examiner and the proband are sitting, and the examiner suddenly moves his or her finger five times in an unpredictable direction in a frontal plane, with movements having an amplitude of about 30 cm and a frequency of once every two seconds. The proband is asked to follow the movements with his or her index finger. The test is abnormal if the proband substantially under- or overshoots or cannot perform pointing movements at all. The finger-nose-finger test is similar, and the proband is asked to alternately touch his or her own nose and then to point to the finger of the examiner.

A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements.

Lack of coordination of movement

Abnormal finger-nose-finger test, Abnormal finger chase test

HP:0001310