Fact of the Day: 31/08/2021

Have you ever seen a doctor tap someone’s knee with a small rubber hammer, and wondered exactly what the doctor is doing and why? 

When doing this reflex test, doctors target a specific area of the knee just below the kneecap known as the patellar tendon. This tendon connects your kneecap and tibia. When it experiences a sharp, sudden tap, it causes your quadriceps to slightly stretch, leading to a subsequent contraction that straightens out your leg in a small kick.

This phenomenon is called the knee-jerk reflex, and it tests whether your central nervous system (CNS) is working properly. People who don’t exhibit this reflex, or have an exaggerated extension of the leg, likely have some form of damage to their CNS.

Reference(s):

• https://www.britannica.com/science/knee-jerk-reflex
• https://www.healthline.com/human-body-maps/leg#knee

Fact Author: Ace

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