What does it mean if your patellar reflex is absent?

Answer 1

The patellar reflex is a reaction designed to prevent your quadriceps muscle from over-stretching When you put the hammer to your knee, you are stretching the tendon. In a healthy individual, this causes feedback to the brain telling it that the muscle is over-stretched. In this pathway there are two main reasons for failure. Firstly, the tendon itself; if it is loose/broken, for example if you have weak connective tissues, it will not stretch the muscle and cause the feedback.

The second reason is a failure in the nervous system in either the relay to the brain, or the motor neurons. Differentiation between the causes depends on other clinical signs.

Answer 2

An absent patellar or knee-jerk reflex could indicate a problem with the nerve supply or function of the reflex arc involving the spinal cord segments or peripheral nerves. This absence may be due to conditions such as nerve damage, spinal cord injury, or certain neurological disorders. Further evaluation by a healthcare provider may be needed to determine the underlying cause.