A positive Babinski Test is characterized by which observation?

• A. Great toe extension, and the rest of the toes splay
• B. Great toe flexion, and the rest of the toes curl
• C. Plantar flexion of the foot
• D. No movement of the toes

Answer: (A)

A positive Babinski sign indicates an upper motor neuron lesion affecting the corticospinal tract. When the lateral sole is stroked, the normal adult response is for the toes to curl downward (plantar flexion). In contrast, a positive Babinski produces dorsiflexion of the big toe and fanning (splaying) of the other toes. This toe extension with toe spreading shows an abnormal plantar reflex and points to UMN involvement. In adults, this is a significant finding; in infants it can be normal due to immature nervous system development.