Lack of Knee Jerk Reflex?

Question

A few moments ago while teaching my girlfriend about pressure points and reflex she relayed to me that she had never, "kicked" upon stimulation of the tendon below her kneecap. She is perfectly healthy and has never sustained any spinal injury thus I told her that this wasn't possible. She clearly has feeling in all extremities and shows no outward indication of any type of nerve difficiency.

Taking this into account I believed her to be incorrect in her claim and I had her sit on a bench where I proceded to check for her knee jerk reflex. She absolutely does not respond to stimulous in the required location. Upon feeling below her kneecap with my fingers she states that she feels a tickle, but there is no sensation whatsoever which signals a reflex or an abnormally located tendon.

I'm a fairly intelligent individual but I can't explain this with my level of understanding in the area of human biology. Any help is appreciated.

Thank you for your reply Dr. Y. As it turns out she is extremely flexible. She can comfortably place both feet behind her head, fully do the "splits", and has superior range of motion in several other aspects. Considering her overall health this would seem to be the most logical choice supposing of course that she doesn't have a brain tumor or some sort of neuropathy.

Answer 1

I assume she's healthy otherwise, or you wouldn't be asking, right? There's any number of vitamin deficiencies that cause a diminished or absent patellar reflex. I also recall reading of a case of a patient who had tuberculosis and this was his only symptom. Odd, really.

On a less paranoid level, that reflex works because it stretches a tendon in the leg there. It's conceivable that her tendon is so stretchy or that there's enough support underneath it that it doesn't respond to normal taps. Is she really flexible?

Answer 2

Absent Knee Reflex

Answer 3

The knee jerk reflex is a lower motor neurone reflex that involves a loop of nerves that is completely independent of the brain. They run from sensors in the skin to the spinal cord and back to the muscles of the leg, creating a jerk. The brain can however suppress this reflex if you concentrate. Try distracting her at the vital moment. How you do this is entirely up to you.

Answer 4

Guide To Chronic Knee Pain!

Answer 5

if youre dead yes your body does stop functioning, but the nerves, sometimes, die a little slower, not much slower, but just a little. Also, what do you think of the Terri Schiavo case, was she brain dead, and does that help. i dont think we really have that technology to tell yet, do you remember Karen Ann Quinlin?

Answer 6

Acupuncture, which involves inserting thin needles into various points on your body, may reduce peripheral neuropathy symptoms.