Photo: Thomas Schönenborn|
How do you throw harder?
Spoiler: There are many, many things that contribute to this, and this article is only about a tiny fraction of them.
Pitching delivery is very complex and has many individual biomechanical sections and parts. Because there are so many parts, it is not so easy to find out which biomechanical characteristics are actually responsible for speed, movement and control.
In principle, forces and speeds correlate much more strongly with throwing speed than positions that can be easily recognized in photos, for example. Roughly speaking, this means that it is not whoever looks better in the photo, but whoever moves faster, throws harder. However, it can be assumed that better positions generally allow faster movements. So it's not all that different after all.
What is scapretraction?
One of the few correlations between such a position and throwing speed is horizontal abduction. Other terms for this are "scapload" or "scap retraction".
It sounds very complicated at first, but it's relatively easy to explain: it's about how far the elbow is pulled behind the line of the shoulder.
Particular attention is paid to the following characteristics: The maximum value, the value at footplant, and subsequently how long the horizontal abduction can be maintained. (It should be noted, however, that values determined using different measurement methods are not as comparable as values determined using the same method - ideally under the same conditions).
Driveline Baseball has found the average at Footcontact (FC, not the same as Footplant, but very similar) to be about 40 degrees, the maximum value is about 57 degrees(https://www.drivelinebaseball.com/2019/03/interpret-biomechanics-reports/).
For pitchers under 75mph, the average horizontal abduction at FC was 35.6 degrees, and for pitchers over 87mph it was 53.8 degrees.
The exact correlations are much more complicated (more details can be found here: https://www.drivelinebaseball.com/2019/02/biomechanics-rewind-look-numbers-last-six-months/), but it can be said very roughly - and really only very roughly - that pitchers who throw harder also have more horizontal abduction on average. Conversely, of course, this does not mean that everyone who reaches 53.8 degrees of scapretraction will automatically throw over 87mph, nor that everyone who has less than 35 degrees of scapretration cannot throw faster than 75mph... However, the probability that this is the case is high.
What are the benefits of Scapretraction?
The retracted elbow is what is most noticeable. Less visible, but much more important, is what happens to the shoulder blade.
It is pulled backwards along the ribcage. This allows it to tilt backwards better, which supports maximum external rotation - the layback. It also facilitates the extension of the thoracic spine, which also simplifies the layback and subsequent acceleration. This is very important for healthy and efficient throwing.
The arm therefore has more time to spend in the layback position and a longer acceleration path. A longer acceleration path allows higher speeds with less acceleration, which reduces the peak load on the arm. You can therefore throw faster and with less strain.
Why does a longer acceleration distance reduce the load peaks?
Let's think of acceleration in a car. But to make it clearer, let's take negative acceleration, i.e. braking. If I want to get from 100 to 0 and have 10 seconds to do so, that's no problem for the body. We have all done this many times. But if you want to do it in less than a second (by driving into a wall, for example), it leaves permanent marks on the body.
Of course, fewer forces act during the throw, and the acceleration distance is not increased 10-fold. The effects are much less drastic, but the principle is the same.
How do I improve Scapretraction?
First of all, the necessary flexibility and mobility must be present. The large and small pectoral muscles, as well as the saw muscle, must therefore be long enough and be able to release precisely (trigger points, stretching exercises for the chest)
At the same time, the rhomboids and trapezius muscles must be sufficiently trained to be able to pull the shoulder blade towards the spine (rowing exercises, "band-pullaparts").
Plyoball pivot pickoffs, plyoball scapretraction throws and roll-in throws are particularly suitable for improving movement coordination in the throwing motion.
However, avoid paying particular attention to it during the throw - this is almost impossible and can negatively affect the timing of your throw. Instead, try to prepare your body for this movement so that it allows and uses it during the throw.