What does it mean when someone says that someone is pronating their elbow or wrist, and is it good or bad.
Pronating is turning your wrist counter-clockwise, and some people believe it is good, but its just a theory.
My pitching coach wants me to pronate a little, but not too much, with my change up. He says that if I overpronate the change up the pitch will flutter and won't really drop the way it is supposed to. He wants the ball to drop more in the vertical - I believe he calls this depth - instead of the horizontal.
Counter-clockwise for a RHP, clockwise for a LHP.
do u have to throw overhead to do pronation?
You can pronate from any arm angle.
Here is Roy Oswalt from over the top.
And Jay Marshall from sidearm/submarine.
how does pronating help you then
It protects the elbow and shoulder on follow-through when the elbow is extended.
Generally speaking most pitchers pronate naturally without trying to. You can overdo it. However, it isn't unusual for a pitching coach to try to get a pitcher to turn the change over a bit more for added movement and to help reduce the velocity.