What is the response observed when Chaddock's reflex is elicited?

Chaddock's reflex is a type of superficial reflex that is tested by stimulating the skin around the lateral malleolus and observing the response in the toes. When this reflex is elicited, the expected response is the extension of the great toe. This is associated with the integrity of the lateral corticospinal tract and is indicative of neurological function, particularly in the context of assessing the upper motor neuron pathway.

The extension of the great toe occurs due to the activation of specific neurological pathways that are responsive to this stimulus, which is typical in healthy individuals. In contrast to other reflex responses—such as flexion of the great toe (which could occur in other tests like the Babinski sign) or flexion/extension of all toes—Chaddock's reflex specifically targets the great toe's extension, making it a unique response that signifies the nervous system's function. Understanding these specific reflex responses is crucial for assessing motor function in clinical practice.