1st source of 'Kinetic Energy' that transfers directly to arm speed is the ability to consistantly drive away from the mound (this is what is missing or not utilized properly in the majority of pitchers).

 

Leg Drive increases seperation in the "HIP and UPPER TORSO" increasing "Torque"

 

Kibler and Chandler calculated that a 20% decrease in kinetic energy delivered from  (back leg drive) to the hip and trunk to the arm requires a 34% increase in the rotational velocity of the shoulder to impart the same amount of force to the hand.

 

Sir Isaac Newton’s Third Law of Motion:  The Law of Reaction - "For every Action force, there is an equal and oppositely-directed Reaction force."

 

"The release velocity of baseball pitches equals the amount of straight-line toward-home-plate force that pitchers apply times the time period over which pitchers apply their forces divided by the mass of the baseballs." - Dr. Mike Marshall