CrichtonBrownes sign, also referred to as Babinski's sign or Babinski reflex, is a medical term used to describe a neurological phenomenon. It is named after the French neurologist Joseph Babinski. In this reflex, the big toe moves upward and the other toes fan out when the sole of the foot is firmly stimulated. This abnormal response indicates damage or dysfunction in the central nervous system, particularly the brain or spinal cord. The term "Babinski's sign" is more commonly used in medical literature, while some may also refer to it as the "CrichtonBrownes sign" to honor the contribution of Sir James Crichton-Browne towards understanding this reflex.