When you feel numb ...

How to take away this numb leg or hand feel it's just easy all you have to do is shake your head and move it in all directions and -that's not to make you look like an idiot- the feeling would just go away in a minute.

If you interested in the scientific reason

The reason why if you shake your head in all direction is that the main package of nerves is in the neck so when you move your nick muscles the pressure would go away from the nerves and the feeling that you had a numb leg or arm is gone.