The Babinski reflex is noted when the baby's big toe extends upward and the other toes fan out in response to the sole of the foot being stroked.
The Babinski reflex is noted when the baby's sole of the foot is stroked firmly from the heel to the toes. Normally, in response to this stimulus, the baby's big toe extends upward and the other toes fan out. This is known as a positive Babinski reflex.
