When taking the ball back, some pitchers extend too far and are not able to get the ball in the cocked position soon enough. Their front leg is planted, their body is ready to turn for the throw, but the ball is too far behind them. Throwing the ball from this position greatly reduces velocity and, more importantly, puts a great deal of stress on the shoulder. Another problem occurs when the palm turns toward the target while bringing the ball up to the cocked position. This also puts too much stress on the arm during the early acceleration of the hand.
Many young pitchers break their hands improperly.
Although when and where a pitcher breaks his hands may not seem real important at first, the break affects arm mechanics and is a root problem with many pitchers. This should be avoided. The breaking of the hands should occur after the pitcher's weight begins moving toward home plate. A more serious problem, in my opinion, involves where the hands break. Pitchers should break their hands directly in front of their bodies, preferably up around the letters.