Eva Voortman - Insideout softball science, April 2020
Throwing, smijten or pitching? Pitching from top till toe to the top - The kinetic chain
What do you need to throw hard? Well actually, everything. From the big toe of the push-off foot, to the hand in your glove, and from the toe of your landing foot to the fingertips of your pitching hand. To accelerate the ball in an optimal way, you need the fingers of your pitching hand to go as fast as they can, and this acceleration literally comes from your big toe. The reasoning behind this, and how you can accelerate your body from that toe to your fingers is what I will explain the coming weeks along findings from scientific articles combined with my experience as a pitcher(trainer). This week: The kinetic chain
In the previous article the kinetic chain came up already: the kinetic chain is literally a chain of movement. The underlying mechanisms of accelerating the body, through the kinetic chain, are rotational velocities of different segments who follow each other up. From pushing off the rubber until releasing the ball, you are accelerating parts of your body in a certain sequence. This sequence is quite logical, you might go from your hip to your torso and not from your elbow to your ankle. The sequence is roughly said from big to small, where you use the power and mass of the big parts of your body to accelerate the smallest parts (the ball and the hand) resulting in high velocities. Kind of like a whiplash effect. This also gives clarity about the fact that a combination of (stiff) force and (smooth) relaxation will lead to the most ideal outcome and result.
Strength and relaxation, two opposites, who, working together, can provide an optimal pitch with velocity. A whip with a less stable base will whip with less force, just like a stiff whip-end won’t reach ultimate acceleration. This would be a point where you can injure yourself, if you nevertheless you want to go harder than your body, the whip, can handle.
Let’s take a step back; The muscles and bones form the base, our body. The body can also be divided in different segments, like mentioned earlier, the rotational velocities of these segments are the underlying mechanisms of the kinetic chain. The segments of the kinetic chain are: the foot, the lower leg, the upper leg, the trunk, the upper arm, the forearm and the hand. As you can see, between all these segments there is a few joints, namely: the ankle, the knee, the hip, the shoulder, the elbow and the wrist.
To add another comparison to the whip and the chain, you could look at the segments as a domino of elastic bands. When you put then at the right tension, and release them in the right order, the last elastic band (the ball) will shoot accordingly in the desired direction.
This brings up the next question, how do you make that happen? Obviously, that is the big question we all try to answer, and what might appear from what is written above, it is quite complicated. In order to pitch a ball, with the optimal velocity, we want to coordinate all the segments, with the right tension and relaxation. Let’s calculate quickly, that would be about, left and right 6, 12 + 1 (trunk) segments over, left and right, 12 joints. 12 joints with multiple degrees of freedom. Degrees of freedom, a new term, important to understand in how the body controls itself and how it learns how to move.
So, degrees of freedom, are degrees that ultimately you want to have unlimited of (which means you can move in many different ways), but also degrees that you freeze when you are not able to do something yet. When you learn something, like for example pitching or hitting, but also something like trying to stand up in a train, you freeze your body. Think of a beginner’s swing or pitch, it looks stiff, rigid. You are searching for a stable base, which is why lean on something in the train, or you grab a railing. You are limiting the degrees of freedom in order to stay in control. The more you practice, the more you feel balanced, the smoother the movements are going to look. Your body slowly learns how to control more degrees of freedom.
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Until the next one!