Patellar reflex

The patellar reflex is when your leg moves by itself when a doctor taps on your knee with a little hammer. It happens because there is a special part in your leg called a tendon that connects your knee cap to your shin bone. When the doctor taps on your knee, he is actually tapping on that tendon. This sends a message to your spinal cord, which is like a big telephone line that connects your brain to the rest of your body. The spinal cord quickly sends a message back to your leg telling it to move, like when you kick a ball. This reflex happens automatically without you even thinking about it, just like when you blink your eyes when something comes near your face. The patellar reflex is a normal and important part of a doctor’s exam to see if your nerves and muscles are working properly.