Often confused with the plantar reflex, the Babinski reflex is also present at birth and fades around the first year. The Babinski reflex appears when the side of the foot is stroked, causing the toes to fan out and the hallux to extend. The reflex is caused by a lack of myelination in the corticospinal tract in young children. The Babinski reflex is a sign of neurological abnormality, e.g. upper motor neurone lesion, in adults.