The Babinski reflex is a diagnostic tool used to assess the function of the central nervous system. This reflex is triggered by stimulating the outer edge of the sole of the foot, which results in the upward movement of the big toe and the spreading of the other toes. The examiner starts the stimulation at the heel and moves towards the base of the toes. In newborns and young infants, who are neurologically immature, the Babinski reflex is typically observed. However, if this reflex is present in older children or adults, it is considered abnormal and may indicate an issue within the brain or spinal cord. Additionally, if the reflex is present on one side but not the other, it can help identify the affected side of the brain. This reflex is also referred to as the Babinski sign, response, phenomenon, and reflex.