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1. alternate involuntary muscular contraction and relaxation in rapid succession.
2. a continuous rhythmic reflex tremor initiated by the spinal cord below an area of spinal cord injury, set in motion by reflex testing.
ankle clonus (foot clonus) a series of abnormal reflex movements of the foot, induced by sudden dorsiflexion, causing alternate contraction and relaxation of the triceps surae muscle.
toe clonus abnormal rhythmic contraction of the great toe, induced by sudden passive extension of its first phalanx.
wrist clonus spasmodic contraction of the hand muscles, induced by forcibly extending the hand at the wrist.
rhythmic contractions and relaxations of the muscles of the forearm excited by a forcible passive extension of the hand.
wrist clo·nus(rist klōnŭs)
Rhythmic contractions and relaxations of the muscles of the forearm excited by a forcible passive extension of the hand.