Friday, November 30, 2012

Pitching Mechanics and "The Kinetic Chain"

The first time I saw Tim Lincecum pitch, way back prior to the 2006 MLB draft, I was hooked. That's all it took. Part of it was his electric, Bugs Bunny like stuff, but another part was his pitching mechanics. Lincecum's pitching mechanics embodied much of what I was, on my own, beginning to piece together about pitching. Namely, that the pitching motion involved a specific sequence of movements that, when performed properly, could incrementally build force. That proper pitching was a summation of force. That each properly executed movement stacked velocity on the one that came right before it. That some types of movements were more effective than others. That flaws in any one part of the sequence would create inefficiency and act as a drag on performance. In short, that "throwing with the entire body" was the best way to increase performance and reduce injuries. It was the kinetic chain right before my very eyes. 

Hitting a baseball is one of the most difficult things to do in sports. Pitching a baseball is one of the most unnatural. During a pitch, the shoulder exceeds 7,000 degrees per second of internal rotation for adult pitchers. It is considered the fastest human movement, a movement generated by the windup process. The stress placed on the arm is tremendous and it's only exacerbated by any mechanical flaws in the delivery.

There is a new wave of interest in managing that stress, spurred on by a combination of escalating salaries and the evolution of information technology, which make it more desirable and easier to study and understand pitching mechanics. Many teams, including the Brewers, view player health as a potential market inefficiency to be exploited. If they can keep their pitchers healthier than their opponents, they'll have a competitive advantage on the field and more efficient production per dollar spent off the field.

The kinetic chain involved in pitching encompasses a coordinated human movement in which both energy and momentum are transferred up through body segments to achieve maximum magnitude in the final segment. The concept of a kinetic chain is developed from the idea that the energy expended in the pitching process is created with large muscle segments and is transferred through the legs and trunk, out to the throwing arm, wrist, and ultimately to the ball. For example, the kinetic chain for throwing consists of the legs, hip, trunk, upper arm, forearm, hand, and the baseball. Pitching's kinetic chain includes a sequence of motions: the stride, rotation of the pelvis or trunk, upper torso rotation, elbow extension, internal shoulder rotation, and wrist flexion. The potential velocity at the distal end where the ball is released is greater if the body segments contribute to the total overall force. Less energy is required if the kinetic chain is executed properly; if the pitcher's mechanics are correct. And, the performance of the pitch - whether velocity, movement, or location - will be improved when the chain is unbroken. But if "the gate breaks" (i.e. one part of the body gets ahead of another, goes off center, etc.), then the chain breaks down and the summation of force becomes inefficient, robbing the pitch of (1) velocity, (2) movement, (3) location, or all three.

At the time, people pointed to Lincecum's size and unorthodox mechanics as reasons to drop him down on draft boards, when in actuality the latter was a tremendous positive, to such an extent that it made the former largely irrelevant. Lincecum was the first high-profile kinetic chain pitcher. There may have been others in baseball's long history, but Lincecum brought it to the mainstream, changing minds and entrenched beliefs along the way. One young pitcher who took note of what Lincecum was doing is Diamondback pitcher Trevor Bauer. Bauer, a mechanical engineering student at UCLA, appreciated and embraced Lincecum's torque-driven delivery as a means of reducing injury risk and maximizing performance.

Lincecum was the trailblazer, Bauer is spreading the word. Bauer, who has the analytical type personality commonly found in mechanical engineering, loves to talk pitching and mechanics, which has made information on the kinetic chain easier to find than ever before. Both Lincecum and Bauer have done much to heighten the discussion and debate surrounding proper pitching mechanics. If you look at their pitching mechanics, the similarities are unmistakeable. Both pitchers stand as prime examples of torque-based/kinetic chain pitching mechanics.

Here's a look at a series of photos of both at key stages in the kinetic chain:


Here, they both utilize a high leg kick, which is an essential part of the kinetic chain. Both pitchers coil up during the leg kick, which creates tension and torque. The angle on the photo of Bauer provides a better visual example of coiling, as you can see the knee of his left leg breaking the vertical plane of his right leg. This wrapping of the knee in the leg kick creates tension in the spine, which generates energy. The high leg kick is also very necessary to set up the proper stride, as seen in the photos below.

I have come to view the windup as two phases, divided by the apex of the leg kick. The first phase is all about sequencing movements to generate force to impart on the baseball, while the second phase is all about properly imparting that force to the baseball. Until the apex of the leg kick, the delivery is about building up force, after the apex of the leg kick it's all about transferring that force to the baseball. While kinetic chain pitchers would probably reject the premise that there are two distinct phases, choosing instead to see each distinct movement as nothing more than another link in the chain, but the "two phases" view is one that seems to suit my thinking on the subject. And, makes a degree of intuitive sense. So, I have referenced it in my past write-ups and likely will continue to do so going forward.    


Upon reaching the apex of the leg-kick, it's time to begin the drive to the plate:

After reaching the apex, the next move is to unleash all the momentum that has been created. Here, they both began their drive to the plate FROM THE APEX of the leg kick. There is a massive difference in the amount of force generated between (1) starting the drive towards the plate from the apex of the leg kick and (2) completely unpacking the leg before beginning the drive to the plate. The force generated by the height of the leg and the body coil are completely wasted if the leg is lowered back down to the ground before driving to the plate. Heading into the 2012 draft, I had concerns about draft prospect Andrew Heaney (my write-up and a video clip of Heaney's pitching mechanics are worth a look if you want to see this leg kick issue for yourself) because he didn't drive towards the plate until after he had already unpacked the leg kick, which is highly inefficient and wastes a tremendous amount of energy generated by the leg kick. In order to pitch at a high level, that lost force must, to some extent, be made up by the arm. Either the lost force will be generated by the arm, causing additional arm stress and likely increasing the risk of injury, or the lost force will be lost forever, reducing the performance level of the pitcher.

Lincecum and Bauer both drive towards the plate from the apex position. You can see that both utilize a lean towards the plate as the leg kick unpacks. This aggressive move is important because it puts them in position to take a long, powerful stride. More and more, it is becoming clear that a long stride is a significant key to the kinetic chain delivery and power pitching in general. (On a related note, ultra-velocity Aroldis Chapman is another pitcher with a very long stride. I've previously posted pictures comparing his stride to that of Lincecum and the similarities are striking.)


Here are photos of Lincecum and Bauer in mid-stride:

As you can see, both pitchers use a very long stride. A stride so long that they almost have to leap off the rubber towards the plate in order to cover that much ground. For kinetic chain pitchers, the long stride is exceptionally important, as it is what permits full, explosive hip rotation. Pitchers who utilize a short stride frequently cut off the rotation of their hips, which limits their ability to transfer the force generated by the body to the baseball. By utilizing a long stride, the pitcher clears the body and allows sufficient time for full and complete rotation of the hips.    

Generally speaking, short stride pitchers are likely to be command and control pitchers (or, power pitchers who generate velocity largely with their arm, which increases the risk of injury), while longer stride pitchers are likely to be power pitchers. But, of course, there are exceptions to every rule, which is what makes baseball, and life, enjoyable. 


The photos in this section are the two most important in this entire post. These photos are the biggest key to the kinetic-chain/torque based method of pitching:

As was mentioned previously, a long stride is important for full-and-complete rotation of the hips. If you look at both of these photos, you can see the hips of both Lincecum and Bauer are almost on a line running from first base to third base, while the shoulders are still on a line running from second base to home plate. At this point, the momentum has moved from the legs to the hips. The long stride permits the pitchers to delay rotating the shoulders. This delayed trunk rotation maximizes the torque in the delivery.

An aggressive, long foot plant allows pitchers to maximize hip rotation, while delaying the back shoulder and arm as long as possible. This high-velocity hip rotation, generated by the legs, along with the loose and delayed torso, PULLS the upper body along at high speed, delivering the arm at the same time. Both Lincecum and Bauer have mentioned that they don't have to ice their arms down after pitching. The simple reason is that they throw with their entire body and the arm is merely pulled along by the explosive hip rotation. The body simply pulls the arm along, reducing stress on the arm. The arm is nothing more than the distal end of the chain, like the person at the end of the whip in a game of crack-the-whip, the conduit for all the momentum generated by the chain. The arm doesn't have to generate the force itself, rather it just channels and imparts that force generated by the sequential movements of the delivery to the baseball.

While the kinetic chain reduces the stress on the arm, it also increases the importance of health of the entire body. For example, lingering injuries to the lower body of a kinetic chain pitcher can cause "the gate to break", leading to a decline in performance. This happened to Trevor Bauer in 2012, causing his velocity to drop and his performance to suffer, as he explained:

"It was like the tale of two pitchers or Jekyll and Hyde," Bauer said. "I'm so heavily dependent on my legs to keep myself in line and generate everything, so when something that low in the chain goes, it's hard to accommodate for it."

Ultimately, these types of mechanics may be a key to understanding how to reduce stress on the arm and avoid pitcher injuries. And, increasing pitcher durability is undoubtedly a way to gain a competitive advantage and increase your return on investment. At the very least, discussion of these pitching mechanics advances the conversation regarding what actually are desirable attributes in a pitcher's mechanics. If a team can more accurately evaluate pitching mechanics, then they can more accurately target players in the draft and teach those new mechanics to players already in the system through their player development department. Both Lincecum and Bauer, through words and deeds, are making a strong case for the use of kinetic chain pitching mechanics to maximize both durability and performance.  

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