Definition of Babinski sign

The Babinski sign is a crucial neurological test that observes the movement of the big toe when the sole of the foot is stimulated. If the big toe moves upward, it could indicate a problem. This response is triggered by stimulating the outer edge of the foot's sole. The examiner starts from the heel and moves towards the toes. There are multiple methods to provoke this response, one of which involves applying firm pressure with the examiner's thumb along the sole's outside edge from back to front. It's important to avoid excessive force, which can cause the foot or toe to withdraw, potentially being mistaken for a Babinski sign.Newborns typically exhibit a Babinski sign due to their neurological immaturity, resulting in the extension of the big toe upon sole stimulation. This reaction is also normal in many young infants, but it usually disappears as they mature. In older children and adults, however, the presence of a Babinski sign is abnormal, indicating a possible issue within the central nervous system (CNS), particularly in the pyramidal tract. If the Babinski sign occurs on only one side, this asymmetry can help pinpoint which side of the CNS is affected. The Babinski sign is also referred to by various other names, such as the plantar reflex, toe phenomenon, or plantar response. It's important to note that the Babinski sign should be described as present or absent, rather than positive or negative. Despite his Slavic-sounding name, Joseph Francois Felix Babinski (1857-1932) was French, and his contributions to medicine ensure his name remains well-known.

Medical Definition & Meaning