11
02
2017

Reviewing Offspeed Pitches and Elbow Torque

With new research developments in other labs and our own facilities, we felt it was a good time to update our data set on offspeed pitches.

Previously, we looked at offspeed pitches and were able to come close to replicating peer-reviewed research with the motus sensor. Essentially, fastballs were the most stressful pitches, with curveballs, sliders, and changeups all having less total torque on the elbow.

But we also wanted to see what would happen if we took velocity into account—mStress but for offspeed pitches. So we took the torque numbers and normalized them for their velocity to see if anything changed.

In fact, things did. We found all of the offspeed pitches had higher normalized relationships than fastballs.

New Research

A recently published study is the first to look at how throwing the slider compares kinetically to a fastball, changeup and curveball.

Since those four pitches make up the majority of pitches thrown in the Major Leagues, this is great news.

Eighteen professional pitchers from one organization participated, throwing 32-40 pitches in total. Each player threw 8-10 pitches of each pitch type. The three fastest pitches thrown for strikes were used for analysis.

Below are the torque values for the elbow and shoulder per pitch type, along with the ball velocity, from the above study.

Overall pitching biomechanics were similar among the slider, fastball, and curveball, with the biggest differences coming between the changeup and the other three pitches.

Below are a few other notable findings:

  • Maximum elbow varus torque was significantly greater in the fastball and slider compared to the changeup.
  • No significant differences in kinetic measurements were found between the slider and fastball and between the slider and curveball.

There were some small differences found elsewhere in the body between pitches.

  • Maximum pelvis angular velocity was significantly greater in the fastball compared with the curveball and changeup.
  • Maximum upper-trunk angular velocity was significantly greater in the fastball compared with the changeup.
  • Maximum shoulder internal-rotation angular velocity was significantly greater in the fastball, slider, and curveball compared to the changeup.

Because of the small differences between pitches found in this study, the authors still point to velocity as the main contributor to injuries.

The authors also noted that “…pitching biomechanics can at best only estimate injury risk and not predict it through shoulder and elbow forces and torques.”

Updated Numbers

To pair with this new study, we also have updated our own numbers.

We pulled data from this summer to add to our database created in the pro offseason of 2016. Each comparison of the four fastest fastballs is compared to the four fastest of said offspeed pitch in the chart below.

The data can be found here.

Overall, fastball torque is slightly higher than the curveball, slider, and changeup. We see the relationship between fastballs to sliders and fastballs to changeups get closer with a bigger sample. Leaving the biggest difference in our sample between fastball and curveball torque. But when we normalized the torque for velocity, the relationships flip, just like we saw previously.

So where does this lead us?

Looking Ahead

First off, both the peer-reviewed study and ours involved college and professional athletes. So these findings should only apply to them. Like we mentioned in our previous article, there is more conflicting evidence with youth pitchers and offspeed pitches.

Just because these studies suggest that fastballs are the most stressful relative to other offspeed pitches doesn’t give youth athletes the green light to throw whatever they want.

The relationship with youth athletes is more complicated by workload concerns, mechanics, and a wider range of movement patterns.

Now, for professional pitchers, how this information is applied depends on how we want to look at the data. Should you use raw torque or mStress? We aren’t quite sure yet.

Because of the similarities in elbow torque it seems like we should start looking beyond the standard kinetics when comparing offspeed pitches. We understand that different pitches often involve slightly different rotations or twists of the wrist. It’s possible that there are more dramatic differences in wrist kinetics than the elbow between pitches.

It’s also possible that those differences can change how the muscles in the forearm work. Leaving the overall torque similar but distributed in a different way.

In the end, the new research still lines up with the research that came before. It looks increasingly likely that any evidence that shows that certain pitches are more stressful than others will come from outside of the standard kinetics. We look forward to continuing our own research and seeing what we find.

This article was written by Research Associate Michael O’Connell

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