Babinski's sign

1. See Babinski's reflex.
2. Weakness of the platysma muscle on the affected side in hemiplegia, evident in such actions as blowing or opening the mouth.
3. A sign of hemiplegia in which the thigh on the paralyzed side flexes and the heel is raised when a person attempts to sit up while lying supine with legs extended and arms crossed upon the chest.
4. A sign of hemiplegia in which the forearm on the affected side, when placed in a position of supination, turns into the pronated position.