What does it mean if you have no knee-jerk reflex?

The normal response is a ‘knee jerk’. This is an example of a reflex, which is an involuntary muscular response elicited by the rubber hammer tapping the associated tendon. When reflex responses are absent this could be a clue that the spinal cord, nerve root, peripheral nerve, or muscle has been damaged.

What is the response in a knee-jerk reflex?

The sharp tap on the tendon slightly stretches the quadriceps, the complex of muscles at the front of the upper leg. In reaction these muscles contract, and the contraction tends to straighten the leg in a kicking motion.

What does the knee reflex test show?

The patellar reflex test is performed to determine the integrity of the neurological function, which is accomplished by hitting the patellar tendon below the knee cap with a test hammer [2].

What is normal knee-jerk reflex?

The normal knee-jerk reflex involves no input to or from the brain. The normal knee-jerk or, “patellar jerk,” reflex is elicited when the knee is tapped below the knee cap (patella). Sensors that detect stretching of the tendon of this area send electrical impulses back to the spinal cord.

What is the cause of no reflex response in the knee?

If there is no response to the knee tap, it may indicate nerve damage. One side of the body reacts slower to a reflex test – If your reflexes are slower on one side it may indicate early onset of progressive disease, or localized nerve damage.

What causes no knee reflex?

Causes of an absent knee and ankle reflex with extensor plantars implies a mixed upper and lower motor neurone lesion, and causes include: subacute combined degeneration of the spinal cord. motor neurone disease.

What are the causes of absent of knee jerk?

Absence of the knee jerk reflex frequently indicates diseases such as pernicious anemia, thyroid disease, or disease of the spinal cord or brain itself. Only on rare occasions are knee jerks absolutely absent in healthy individuals.”

What happens during a knee jerk reflex?

Knee-jerk reflex, also called patellar reflex, sudden kicking movement of the lower leg in response to a sharp tap on the patellar tendon, which lies just below the kneecap.