Throwing mechanics and arm health are directly correlated, and affect every player at every position - not jut pitchers. If a player does not develop good habits early in their career for arm preparation and after-care the effects can be harmful to the body. There is a very fine line between the health and use of their arm.
The main goal of a batter is, of course, to get on base via a hit or base on balls. There are 3 primary and basic points of emphasis when a batter steps in the box. First is vision, followed by timing and finally balance. To take a swing with poor balance is worthless and hitting a ball with no vision or sense of timing is nearly impossible.
