Let’s compare Aroldis Chapman and Jared Weaver: Pelvic-Scapular-Separation-Style
Sean recently texted me an article talking about the concept of “Hip to Shoulder Separation” that has become popular in recent years and asked for my thoughts—there were plenty. It sent me down a pitching mechanics wormhole. Please enjoy.
First off, baseball players and especially coaches need to improve their anatomical vocabulary. We often talk about the hips when we are actually talking about the relationship between the pelvis and the spine rather than the femoral head and the acetabulum. When we say shoulder, are we talking about the gleno-humeral joint or the scapular-thoracic joint, or the whole shoulder complex? This lack of common and proper vocabulary adds unneeded confusion when trying to express our thoughts. I liken it to trying to write a book, but only having access to half of the alphabet. You may have a great story in your head, but if someone tried to read it they’d have no idea what you were trying to say.
The last anatomical critique I’ll make before jumping into an analysis of “Hip to Shoulder Separation” is the use of the word core and how most people think the core works. The core is more than just your abs. The core is a group of muscles around your spine, starting at the bottom with the pelvic floor and going all the way up to the deep neck flexors. It is comprised mainly of muscles that contain a high percentage of fibers that are built for stability and endurance. Your core is not going to be directly responsible for rapid motions. It is meant to be an anchor to give you proximal stability, which allows for you to have distal mobility. In other words, the more stable your core is, the greater your potential to get the legs and arms moving quicker and stronger and thus throwing and hitting harder.
Additionally, when you use the muscles meant for motion to stabilize, you put yourself at a greater risk of injury because these muscles will fatigue quicker and will no longer be able to provide the stability needed to complete whatever motion you are trying to accomplish. With the violence of the pitching motion, stability is of the utmost importance.
Now that I’m off my soapbox, let’s get into the nitty-gritty of what is going on when we create Pelvic-Scapular-Separation. One of the biggest proponents of this concept is Tom House, who is mentioned extensively in Matthew Schissel’s article at Inning’s Pitched (the one that set off a lot of feelings inside of me). I worked under a House-trained pitching coach between college and graduate school. His approach to pitching mechanics changed the way I look at baseball and greatly increased my desire to learn more about biomechanics. I’ve extrapolated a lot from his work and applied it to the swing.
“Hip-Shoulder-Separation” was one of the most important concepts. It makes sense on a fundamental level—by stretching the body you put it under tension like an elastic band, creating potential energy, which can be released as kinetic energy. Because energy cannot be created or destroyed, only transferred, by generating more potential energy you can release more kinetic energy and throw harder. I completely agree with this. As with much of my disagreement with House’s approach, the problem I have is with the rationale used to describe what is going on in this process and how we go about creating it.
As Schissel, puts it: “The hips open up and fire before the core engages, and then the shoulders and arm follows. So the hips need to be strong, mobile, and steady to keep everything else in line and on track.” It’s a great attempt at describing what is going on, but is severely misguided.
The hips (pelvis?) can’t efficiently open up and fire without the core being engaged already. By trying to get stability from the hip musculature, a pitcher is limiting their potential and setting themselves up for injury. The stability we see comes from the core and allows the pelvis to open up. In order for this to happen effectively, the core musculature must be at a proper length-tension relationship and alignment. In an efficient system, when a person changes their center of mass over their base of support, the core will kick in automatically. Below is a freeze frame of Aroldis Chapman at the very beginning of his leg kick (a change in base of support) before he throws the fastest pitch ever recorded. If anyone is ever going to have this proper relationship, it is this man, on this pitch.
To continue reading about Jared Weaver and Aroldis Chapman’s pitching mechanics, please click on over to offthebenchbaseball.com