Babinski reflex - The reflex occurs upon stroking of the sole of the foot with a sharp object such as a pen. If the reflex occurs in adults as illustrated at bottom it may be due to nerve damage or disease.
Plantar Reflex: Reasons why my Child may be a Toe Walker and has Poor Balance and Coordination
The Babinski sign indicates upper motor neuron lesion constituting damage to the corticospinal tract. Infants show an extensor response. A baby's smaller toes will fan out and their big toe will dorsiflex slowly. This happens because the corticospinal pathways that run from the brain down the spinal cord are not fully myelinated, so the reflex is not inhibited by the cerebral cortex. The extensor response disappears around 12 to 24 month