Diadochokinesia

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Diadochokinesia is the ability to perform fast, alternating movements. Examples include quickly tapping the hand or fingers, turning the palm from up to down and back, or moving a limb between bent and straight positions. In speech therapy, it also describes how quickly a person can stop one movement and start the opposite one. The speed and rhythm of these alternating movements are called alternate motion rates (AMR) or sequential motor rates (SMR). If someone cannot do these movements smoothly, this is called dysdiadochokinesia, a sign that can occur with cerebellar (balance and coordination) problems. Clinicians use several tests to check for these disturbances.