Definition reprinted with permission from Culebras, Antonio, Clinical Handbook of Sleep Disorders, Butterworth-Heinemann
A rapid partial flexion of the foot at the ankle, extension of the big toe, and partial flexion of the knee and hip that occurs during sleep. The movements occur with a periodicity of 20-60 seconds in a stereotyped pattern lasting 0.5-5.0 seconds, and are a characteristic feature of the periodic limb movement disorder.
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