Diadochokinesia or diadochokinesis is the ability to make antagonistic movements in quick succession, alternately bringing a limb into opposite positions, as of

flexion Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...

and

extension Extension, extend or extended may refer to: Mathematics Logic or set theory * Axiom of extensionality * Extensible cardinal * Extension (model theory) * Extension (predicate logic), the set of tuples of values that satisfy the predicate * E ...

or of

pronation Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...

and

supination Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...

. Speech-language pathology defines it as the speed necessary to stop a determined motor impulse and substitute it with its opposite. The relative timing of this kind of movements is also called alternate motion rates (AMR) or sequential motor rates (SMR). Loss of ability (

dysdiadochokinesia Dysdiadochokinesia (DDK) is the medical term for an impaired ability to perform rapid, alternating movements (i.e., diadochokinesia). Complete inability is called adiadochokinesia. The term is from Greek ''δυς'' ''dys'' "bad", ''διάδοχος ...

) is characteristic of

cerebellar diseases The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebel ...

. Many clinical tests may be employed to test for such disturbances. * ''Alternating movements'': Patient is told e.g. to pronate and supinate their hands in rapid succession, holding forearms vertically. In cerebellar diseases, the movements are irregular and inaccurate; in case of the pyramidal tract lesion the motion may be slowed or incomplete. * '' Stewart-Holmes rebound sign'': Patient tries to flex the elbow against applied resistance. When physician's grip is suddenly released, the patient should be able to deter it from rebounding. With cerebellar disease, the forearm may sway in several cycles. The patient may even strike themself if not guarded. * Various instrumental techniques can be used to investigate speech motor skills, such as imaging movement transduction and point tracking.

References

{{reflist Diagnostic neurology Medical terminology Symptoms and signs: Nervous system

See also

References