explain when you hit the patella knee cap your reflexes jerk a little. i know that due to sending a signal to?
405981
the knee jerk reflex, is caused by stretch in your guadriceps. there are receptors in the tendon that sense stretch of the tendon and send messages, as you said, to the spinal cord. The  spinal cord then tells the quads to tighten so the tendon doesn't become too stretched and break.  Now the hand position, what that does is distract the person from controlling the muscles.  The reflex is unconscious but can be overriden if you think about it, so doctors try to make you think about holding your arms together so you aren't impeding your reflex
64624
less than that if the knee is in a locked stationary position.
738730
Your "thought" of movement starts in the precentral gyrus, the signal travels to the cerebellum via pontine nuclei, then the action potential is sent, but it is sloppy movement and still needs calibration.  This is done after afferent signals from the proprioceptive neurons combine with the first set of efferents and the 2 are compared.  The signals then are refined by the precentral gyrus and secondary impusles for the same movement are again sent down the pathway.
749680
If you are new to it or you havent played it in a while then its natural that your arm will turn red so juss keep practicing and get used to the ball hitting your arm because thats what its intended to do... sooner of later the redding of your arm will stop since youre used to it.
199287
Also, move your knees from side to side. It releases a trapped nerve if it's siatica.
62498
when you sit on your leg for instance the circulation slows down enough for your nerves to start tingling signaling your body to move to get the blood circulating again..
266472
Well, I'm recovering from a broken kneecap. My Doctor told me to lay on my back on the floor.\nDraw my one knee up so it points to the ceiling while the foot is flat on the floor. Keep it there.\nThe other knee? Keeping your leg straight, lift that leg about 10 inches off the ground & hold for 10 seconds. Do 100 daily. This strengthens the knee.
754955
Interesting question. Possibly related to our ancestors time in the trees. A strong grip would be essential for survival and this involuntary reflex is a relic from that time.
933976
yes, that sounds like the right thing to do. ice on and off 20 minute intervals, elevate, stay off it for a while, u know- all that stuff. if the problem persists, consult a physician.\nit doesnt sound like u really did anything significantly damaging to ur knee from ur description, like i doubt u tore anything, because u experienced no pain right away. it sounds like it may be a bone bruise around ur patella, or something along those lines.\nu probably should see a doctor if it keeps hurting, or just to be on the safe side, yknow? but i wouldnt be too worried, it doesnt sound terrible
485373
Some joint of mine always feels a little bit of discomfort.  But that's ok, as it reminds me to be cautious while active.  These little pains help keep me from experiencing major pain from injury.
886603
YES!!!! the whole purpsose of a cortisone shot is so you go numb... I had a level 3 ankle sprain, and to get on the field faster I had a cortison shot in my ankle... From my knee down ot my ankle felt numb... but within a day i could not feel the numbness anymore, and of course it numbed all pain in my ankle..my Dr told me this was normal, but maybe just to be on the safe side give your Dr. a quick phone call and ask his office.. every persons body is different
542143
Depends on the reflex. Myotatic is the simplest. One synapse.\n\nAfferent Ia axon (originating in a muscle spindle) enters the spinal cord and synapses on an alpha motor neuron innervating the same muscle, causing it to fire. This reflex mediates the "knee-jerk" your doctor checks for.\n\nhttp://academic.uofs.edu/faculty/kosmahle1/courses/pt351/lect351/reflxarc.JPG\n\nExample in picture form.
492291
Bend your knees slightly, keep your center of gravity underneath you without leaning too much on one leg.  And most important of all, use your back foot like a break as you drag it on its side to help stop your momentum.
994398
Because you are putting weight on your knees, which affects from there down
277289
Pulling it tighter will decrease the amplitude. Allowing slack will increase amplitude. Increase the input frequency
941334
stimulus to a nerve center such as the knee or elbow can cause an involuntary flection of the appendage (You kow when you get a physical and the doctor uses that little hammer thinggy and hits you just below the knee cap and your leg jumps?)\nOther involuntary responses could be blinking your eyes when something comes at your face, or as others noted, a sexual response to stimuli
506570
its this thing called reflex arc. see this pic n u might get it. it has stuff to do with neurons n i dont feel like writing the whole crap.\nlol thnx hmmm didnt see wat is said :) its actually\nhttp://dtc.pima.edu/~biology/201alpha/lesson10/reflexarc.jpg