When you sit on your foot, you temporarily compress, or squash, the nerves in that area. These nerves can't send messages back to the brain normally, and so for the moment, the connection is cut off and you don't feel anything. It's kind of like a phone call where your friend hangs up and you haven't yet: Your brain is saying "hello," but your foot isn't able to answer.
After you stand up or uncross your legs and the nerves are no longer compressed, the feeling in your foot soon comes back. It might feel a bit tingly as this happens, like pins and needles or even a bit painful. But it only lasts a few seconds as the connection returns to normal, and it won't hurt your body.
from: kidshealth.org
It's a lack of blood flow getting into your hands and feet. Ever notice how it usually happens when you're sitting cross legged, or somehow sitting on an extremity? Your weight makes it harder for the blood to get through your arteries.
I'm pretty sure it has something to do with the nerves. I know it isn't that they are pinched cuz that is alot of pain. I can't think of what is is called but it is with the nerves
To make it stop just shake your hand and leg around
okayy, thankks!