ThrowGasEatA55 has a good point(s). For those with mature bodies, strength and muscular control that passes on this choreography matching control and quality locations, it's a doable part of pitching. I, on the other hand, am not a big fan of this movement.
Why? In the coaching circles in my day, this kind of movement is (was) called torque resistance. Torque resistance is where the lower part of the body actually goes partially towards home plate, thus loading up the upper part of the body with core resistance as the torso and upper shoulders swing around and push through the resistance loaded up by the lower part of the body. I don't think I explained that right - but for now, it's the best that I can do.
In any event, a lot of guys did get a few more miles per hour tossing cheese, but I noticed a tradeoff later on in their season where continued form in this manner lead to location problems, a high percentage of not adjusting to the plate umpire's strike influence(s), and a lot of pitches in the dirt - thus beating the backstop to death and passed balls.
bluezone63, I assume that you're an amateur, probably under 15 - am I right? If not, could you describe your self and why you asked this question?
When I answered the way I did, I assumed that you're playing ball and maybe, just maybe, you're experiencing this movement and as such, may be having some issues. If not, then perhaps your question is just out of curiosity.