Power-Pronation is a throwing technique, I initially developed from experiments in football throwing. However, the technique has proved useful in throwing experiments with baseballs and softballs and in the swinging of a tennis racket for a more powerful tennis serve. Power-Pronation starts with supination of the wrist as the throwing arm is drawn back for the loading phase and ends with a more powerful pronation of the wrist as the ball is released, hence the term Power-Pronation.
The following article written by national baseball writer Steve Krah, describes Power-Pronation as an alternative way for pitchers to throw a baseball: Power-Pronation
Steve Krah is a long-time member of the Society For American Baseball Research - SABR. His baseball blog covers the baseball scene in the great state of Indiana: www.IndianaRBI.com