You said it has nothing to do with nerves but that's wrong. When your patellar tendon stretches it send's out a signal through sensory nerves. When that signal reaches your spinal cord, it gets inverted to a signal in the motor nerves. That signal will reach your muscles and cause them to contract. That is basically how a reflex works. That's why you can't control them. It just never reaches the brain (except for the brainstem, which is responsible for some, still involuntarily, reflexes).
I did this once: Doctor: *Taps left knee, watches it jerk* Me: *Clenches teeth while doctor taps my right knee, causing the right knee to jerk much less* Doctor: Umm . . . . Me: Sorry, I was clenching my teeth. Go ahead and tap it again. Doctor: I hate it when people use that trick on me. I'm glad not too many people know it.
You said it has nothing to do with nerves but that's wrong. When your patellar tendon stretches it send's out a signal through sensory nerves. When that signal reaches your spinal cord, it gets inverted to a signal in the motor nerves. That signal will reach your muscles and cause them to contract. That is basically how a reflex works. That's why you can't control them. It just never reaches the brain (except for the brainstem, which is responsible for some, still involuntarily, reflexes).
I did this once:
Doctor: *Taps left knee, watches it jerk*
Me: *Clenches teeth while doctor taps my right knee, causing the right knee to jerk much less*
Doctor: Umm . . . .
Me: Sorry, I was clenching my teeth. Go ahead and tap it again.
Doctor: I hate it when people use that trick on me. I'm glad not too many people know it.
now maybe too many people know it (how does it feel to be replied to after 6 years ?)
@@dontmesswiththeriddim2699 how does it feel to be replied to after 8 months
@@xeon6907 How does it fee to be ignored for 2 months
@@Bluewater225 yes
How does it feel to be replied after 7 months?
cant make my knee jerk. I might need help
Me too
Same
Same last time I got a physical it didn’t jerk lol
I'm def gonna try this at home
This is fun. But I can't get my knee to jerk.
Same
It took me quite a few goes to hit exactly the right spot. There's obviously a knack to it.
umm what if its not working at all for me.. And whem other people try to do it on my knee it doesnt work. Is this a abnormal reflex?
I thought the same, but I discovered I have to hit exactly the right spot. It's more difficult than these girls make it look.
0:56 try it for yourself me who's recovering from a complete tear hm probably not a good idea
This is so cool lol
neat
I was able to wiggle my ring finger even though my middle finger was tucked beneath my hand, weird.👀
Probably it's simple reflex action
Well obviously that’s literally what they said
Please video make in hindi.
no fck u
Lmao
Hindi mei search karlo bhai
Weird... I can wiggle my ringer finger a little on my left hand, but can't even make it twitch on my right hand.
It's because your left hand is double jointed!
@@marashello7960 Mine too but i cant move it lol
Check this test if you are fast enough:
th-cam.com/video/0NCeH7CqsEE/w-d-xo.html