Do you have a Babinski's reflex?

A reflex is a response we cannot control. Typically, doctors will check the reflex at the elbow, knee and heel to see if it elicits a response. Without diving into the neurology of how a reflex works, it basically skips the “thinking” part of the process.

Let's look at an example:

• Input: There is a nail sticking out of the ground, you take a step and FEEL the tip of the nail
• Brain processing: Initiates reflex 
• Output: You shift your weight to the opposite leg and quickly pull your heel off the nail. 

SOOO what is a “Babinski’s reflex”?

• This is considered a PATHOLOGICAL reflex. It can be checked a few different ways, but the most common is running the end of a reflex hammer along the bottom of the foot.
• In a normal response, for an adult patient, the toes should curl up (Acharya).
• An “abnormal response” in an adult would be the toes flaring out. 
  • This is a sign of an upper motor neuron lesion. Meaning that the brain or spinal cord is affected. This is commonly seen in patients who have had a concussion, traumatic brain injury or neurodegenerative disease (Lance).
  • Note: the toes flaring out is a NORMAL response in infants. The toes splay to help create more surface area to help the baby exit the womb. This reflex typically disappears within the first year of life (Modrell).

Takeaway:
Reflexes are designed as a protective mechanism. They can become dysfunctional when there is damage to the nervous system. It is important to note that a Babinski’s reflex should be assessed along with clinical findings to determine if further investigation is needed. 

References:
Acharya, Aninda B., Radia T. Jamil, and Jeffrey J. Dewey. "Babinski reflex." StatPearls [Internet]. StatPearls Publishing, 2022.

Lance, J. "The Babinski sign." Journal of Neurology, Neurosurgery, and Psychiatry 73.4 (2002): 360.

Modrell, Alexa K., and Prasanna Tadi. "Primitive reflexes." StatPearls [Internet]. StatPearls Publishing, 2021.

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