Babinski's sign

Babinski's sign

n.

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.

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Babinski's sign

Etymology: Joseph Babinski

a series of partial responses that are pathognomonic of different degrees of upper motor neuron disease, including (1) absence of an ankle jerk in sciatica; (2) an extensor plantar response, with an extension of the great toe and adduction of the other toes; (3) a more pronounced concentration of platysma on the unaffected side during blowing or whistling; (4) pronation that occurs when an arm affected by paralysis is placed in supination; and (5) when a patient in a supine position with arms crossed over the chest attempts to assume a sitting position, the thigh on the affected side is flexed, and the heel is raised, while the leg on the unaffected side remains flat.