If you look at the photographs in this link, you’ll see examples of the natural throwing pattern as adapted for baseball pitching. You can see that the legs, pelvis, trunk and shoulders are engaged so as to produce a dynamic stretch of the serape muscles running diagonally from the shoulder to the hip. It’s the muscles involved in this group that are responsible for the development of the internal forces that transfer momentum to the arms or legs in throwing or kicking.
The reason why I put Rufus up recently is that there is a strong similarity between the way he stretches the slingshot from both ends simultaneously, and the way that somebody throwing a ball double-stretches the serape muscles. This is the shoulder-hip separation referred to in the first article.
This double-stretching not only engages the serial elastic component of muscle, but also the muscle spindles embedded within the muscle. The faster you can initiate this stretch, the more powerful the contractual force that is developed as a consequence.
So the trick is, how do you get this double stretch effect?
In pitching you see a very exaggerated example of the front leg stepping forward while the rear shoulder pulls back. In fighting, naturally this principle has to be adapted to the time frame and tactical situation required, so the movement won’t look obvious as it does with the pitchers. However, in some form the double-stretch when present will enhance the force development of your shot. I used to tell Richard La Plante when he asked me how I got my power that I’d simply refined the process of throwing a stone.
I’ve been talking about the serape muscles and the importance of their engagement across the diagonal of the torso for thirty years, although I think I was mispronouncing the word 'serape' on the videos made in the late 1990s. There’s nothing new in the concept; it’s been around since 1922 in Logan and McKinley’s Kinesiology. I picked up the idea in the kinesiology books I bought in the early 1970s.
Have a look at the photos and at Rufus. Don’t get caught up in the detail, but get a feel for the separation and double stretch; i.e., stretching from both ends simultaneously and engaging as many muscle groups as you can in the kinetic chain. No passengers.