When you bang your knee why do we immediately start rubbing it?
962889
It is easy.When you bump or bang or even have an itch,the nerve automatically sends a signal to your brain.When the brain receives the message,the message sent will cause you to itch or rub the area that is affected.\n\nSame as with yawns.When the brain lacks oxygen,it causes you to automatically yawn.
14672
This is a mental thing.  You've told yourself that you will feel relaxed after you pop your knuckels, so you do.  It is not a proven way to relax, and it doesn't relax me.  It gives me anxiety to hear someones knuckles pop.  \n\nThe sound is produced by air trapped inbetween you knuckles, and when you pull it releases the air.  Also, a common misconception is that cracking your knuckles will cause arthritus.  It actually does not.  Your just releasing the oxygen inbetween your knuckles.
1178158
It has been incorrectly attributed to synovial fluid moving suddenly (popping) from one side of the synovial fluid cavity to the other when the one side is under pressure.\n\nIt is ACTUALLY the sudden stretching and 'relaxing' of your tendons over your joints as you put the tendons under tension when snapping your fingers.
915100
the young people in my family grow tall quickly and they play bball.  When they developed pain above the knee (and one of them below the knee) I took them to a chiropractor.  We learned that the bone grows faster than the ligaments attached to them.  That stretches the ligament and causes pain.  Especially during impact like jumping for the hoop.  They used to call this growing pains.  Then they gave it a name "osgood-slaughter" after the doctors who found it I guess.  Our doctor gave the kids a funky narrow brace that wraps around the leg at the point of pain.  The reasoning is that it disperses the stress to other areas.  The kids use it during bb.  It works!  Also they take good multiple vitamins and eat well.  No sugar, no drugs.  Keep in mind that water lubricates your joints too.  If you are serious about being an athlete you need to take good care of your body now.  check out this website http://health.yahoo.com/conditions/.  \n\nEventually your body catches up with itself and the pain will stop.  good luck in reaching your goal in life.  It's nice when you get paid to do what you love.
1019446
Called bursitis of the knee, caused by direct trauma/force.It id swollen due to the body trying to repair that area of the body.It swelled again most likely not getting the right treatment in the begining.
1160457
If you have some swelling located in the back of your knee; you may have a Baker's Cyst. This is named after a physician who described it first (Dr. William Morrant Baker (1839-1896), not because bakers have these cysts.\n\nThe cyst usually occurs due to some other problem in your knee such as arthritis or even a tear of your meniscus. The swelling from this problem causes fluid to build up in your knee. This fluid pushes out the weakest point of your joint capsule surrounding your knee. This is usually to the back portion of your knee capsule, and a cyst forms.
965197
No, this is not uncommon at all. When you sustain any type of injury, your heart beats faster and as a result, you start to sweat. This happens more often with blood wounds, because typically when you bleed, or see blood, your heart tends to beat faster then say, if you bruised your knee or something. So it's not "gross or rank", you just have a very up-to-speed heart. Hope this helps!
967529
hmmm,\n how to describe this?...\nyou go to a wall, while facing the wall, place your hands on the wall, place the foot of the shin you need to stretch behind you, about 2 feet away, place the other foot closer to the wall. then to stretch the front of the shin, (the leg that is behind you), bend your knee, don't put the knee too close to the ground, not good for your joints...\nhope this makes sense??
311161
a knee jerk is a instant reflex of either the knee  and or a way to describe something meaning it is a reflexivity-or something being automatic, and happening without thought. Not really sure about this question, but this is What i think . it's better then no answer. good luck everyone
585616
First, if you are having pain then there is something wrong and you should not just "suck it up".  You need to specify what activities are causing pain and when.  \n\nAsk yourself these special questions:\nIs it sharp pain or dull pain? (chemical vs. mechanical pain)\nIs it intermittent or constant? (activity driven or constant)\nDoes the knee "give way" (esp. with descending stairs)? (possible ligaments instability)\nDoes the knee lock (won't straighten all the way)? (possible loose body in joint or meniscus tear)\nDo you get popping/grinding/"rice crispies" feeling with moving the knee? (possible chondromalacia, osteoarthritis)\n\nThe treatment depends on the problem.
625281
Its a balancing act- Muscle stretch receptors will cause contraction to keep the muscle from being damage by over-stretching.  It takes a fairly large amount of muscle tension to cause significant stretch in the tendons, though-so when the tendon stretch receptor are activated, it means the muscle is pulling extremely hard on the tendon, which could lead to tendon and joint damage-thus then there is a signal to back off.  In the end, the body decides it is better to have a torn muscle than to damage the joint itself- So, a little muscle stretch, like during sports, the body contracts the muscle to protect it.  But, if the tension goes up too much- A lot of tension on the joint-puts the joint at risk now, which is harder to heal and a more damaging injury than a muscle tear, so the body relaxes the muscle- Hey, you got a groin pull-ouch, a few weeks off, you're ok- But tear up the knee joint, or pop out your hip-thats a long-term problem.
361327
malicious wounding used to punish enemies, or as a drastic form of torture. They injure the victim in the knee, especially by shooting. This generally cripples the person for life. The term knee-capping is often used as a metaphor to label political criticism as an "attack".\n\nit is very very very painful.
946508
I call it proper punishment.\nIf you touch something and get grounded, you probably shouldn't have touched it. Didn't momma teach you not to touch things that don't belong to you?\n\nYou're discharging a static electricity charge from your body to ground. \nAs you walk around your shoes build a static charge on your skin. If the humidity is low your body doesn't discharge the static as readily as it would if it were more humid.\nWhen you touch something metal your body is discharging the energy back to earth.
511544
it is the same theory as why you know when you are hurting .it is your brains autonomic reaction to an action.pinch yourself and it will hurt but not as much as if some one else did it unexpectedly so tickle yourself you know whats going to happen so your mind tells you it does not feel the same,therefore it does not tickle .you feel some sensation but not the same reaction
1090311
where's your other hand rubbing?
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
421004
Same thing happen to me it started to swell and caused me alot of pain in my left knee. I did permanent damage to it. I pulled the muscles and did a bunch of damage behind the knee cap. It hasn't been the same now, if I do anything to strenuous it flares up. I have to take vitamins now just for my knee, and yeah it sucks, but its not worth the pain. In other words your joint is stressed out.