“” Training Posture and Forward Bend with K-Vest - Driveline Baseball

Training Posture and Forward Bend with K-Vest

| Blog Article, Hitting, Offseason Training
Reading Time: 8 minutes
Posture improvements

By John Soteropulos, Hitting Trainer

“I found out about Driveline from my friend John Soteropulos. We actually went to high school together at Loyola in Los Angeles. I knew I needed to do something different in my game to improve and become a better baseball player.” – Angelo Armenta

It’s always exciting when a friend makes the trip up to Driveline. The sense of camaraderie becomes amplified, and the training floor environment heightens in energy and purpose even further. 

Hitting Assessment

When Angelo arrived, the first thing we did was take him through our hitting assessment.  Unsurprisingly, he already did a lot of things well – above average barrel consistency, solid bat speed, and good ball flight.

However, one of the biggest areas for improvement we identified was his posture, more specifically his torso forward bend. Angelo is a switch hitter, but this blog is going to highlight his left-handed swing. On the right is a video of Angelo’s assessment week. On the left is his exit week.

Last Day vs. First Day at Driveline

Correcting Excessive Torso Forward Bend

The main issue with Angelo’s swing was the excessive amount of torso forward bend (green line) he gained during his stride phase. We generally look for hitters to maintain a constant amount of forward bend during their stride phase, or gradually gain forward bend into heel strike. With Angelo, his torso forward bend was increasing from ≈20° at first move all the way to ≈50° at heel strike.

While some successful hitters are more bent over and exhibit greater degrees forward bend at heel strike (think Ricky Hendersons and Mo Vaughns of the world) anything above 40° is generally an area we flag for improvement.

Angelo’s first week K-Vest graph is below. Notice the green forward bend increasing while he strides. Below that is an example of an efficient upper body angles graph. Notice in the efficient example, the green forward bend line stays mostly parallel to the x-axis.

Angelo’s First Day K-Vest vs Efficient Example Graph

To visualize what this move looks like, take a look at Angelo’s K-vest animation. I recommend viewing this GIF at least twice. First time, watch only the animation. Second time, watch the “bend” measurement and notice how Angelo’s forward bend increases all the way up to 51°. 

Angelo’s First Day K-Vest Animation

Up next, we have a screenshot from Angelo’s assessment K-vest report. The main takeaway here is that he was landing with anywhere between 45°-51° of forward bend. 

Forward bend
Angelo’s First Day K-Vest Report

Excessive forward bend can make it very difficult for hitters to produce flush contact on pitches up in the zone, especially if these pitches are fastballs with a lot of lift. Because elevated fastballs are being thrown more and more every year, it is important that we give our hitters a movement solution to combat this pitch. 

In addition to high fastballs becoming more prevalent, pitchers are throwing harder and their pitches possess more movement. Because of this, we want to give our hitters a swing that can produce against higher velocity pitches, more severe movement profiles, and against pitches at various locations in the strike zone. For Angelo, this meant making an adjustment to his posture. 

Drills to Improve Posture

With the goal of getting Angelo more upright to improve his posture, the first drill we implemented during his swing design was the high tee inside pitch. The intent during this drill is to hit the ball hard to RF between 10-30° with backspin.

This drill helped set his posture for the high pitch and prevented him from landing with excessive forward bend. If he landed too bent over, his bat was forced to loop upwards to this pitch. This swing will produce a lot of topspin ground balls and high fly balls over 35°. 

The next drill we implemented was the high inside fastball machine. This drill is a more advanced progression of the high tee. The intent is the same as the tee – hard line drives to RF between 10-30° with backspin – but the level of difficulty is much higher,  for a couple of reasons: 

  1. The moving pitch adds an extra degree of freedom to the ball-bat collision. This forces the hitter to have a proper swing plane throughout a longer point of contact range. The tee challenges a swing at one specific contact point, whereas the machine requires a swing that will square the ball up at different points in the zone. 
  2. Four-seam fastballs at the top of the zone have the flattest vertical approach angle (VAA) of any pitch. In order to be consistent with this drill, a flatter swing path is required. 

Here’s Angelo with a really good rep. 

Introducing Variability

After he got a feel for the machine, we progressed to live arm batting practice. The idea here was to introduce variability, in the form of pitch location, and see how Angelo’s movements held up in a more randomized environment.

Our goal as trainers is to transfer these swing changes to the game, and live arm BP gets us one step closer to that. 

In this next GIF, you can see how Angelo’s taller posture allows his bat path to square up a high and away pitch. His assessment data showed us when he hit the ball to the opposite field, his exit velocity decreased while his launch angle increased.

This is a lethal combo, but his new posture adjustments addressed this flaw. With his improved posture, Angelo was able to hit to the opposite field with a lower launch angle and higher exit velocity with swings like this.

As a side-note, one of Angelo’s favorite parts about training at Driveline was Shortbox Tuesdays. Shortbox is where employees take the mound and throw mixed pitch at-bats to our hitting trainees. It makes for quite a competitive training environment!

Like my conversation with Aaron Takacs, I had to hear Angelo’s thoughts on who he thought had the best short box arsenal:

Had to be Dan Comstock… John had weak stuff, with a changeup that floated over the plate like a beach ball

Pretty small beach ball if you ask me…


Swing Posture Improvements

When we compare his last week to his first week, Angelo made huge improvements with his swing posture. The green line in these graphs represents torso forward bend. Notice how from his first day to his last day, he has much less forward bend : 18°-28° versus 40°-50°.

Moreover, if you look at the shape of the forward bend curve from his recent swings, the green line stays parallel to the x-axis, meaning that he is striding and maintaining the same amount of bend. While on the right with his first week swings, the green line continually increases. This means he is continuing to gain forward bend while striding. 

Upper Body Angles Graph

Angelo went from landing with 45°+ of forward bend to consistently landing with 20°-28°. This puts him in a much better position to cover pitches up in the zone as well as hit the ball flush the other way.  

Forward Bend
Taller Posture vs. Too Much Forward Bend

Finally, Angelo’s most recent K-vest animation helps us visualize these posture adjustments. Again, I recommend viewing this GIF twice. First time, watch only the animation. Second time, watch the “bend” measurement. You can see that now he lands much more upright, around 27°.

Visualizing posture adjustments
Angelo’s K-Vest Swing from his Last Week

Comparing the Swings

Comparing Edgertronic footage from his last day against his first day, we can really visualize the posture changes and how they affect his bat path. On the left, he strides with taller posture and maintains this bend up until heel strike and throughout the swing.

On the right, he gains forward bend while striding, and he lands very bent over at heel strike. This exaggerated posture causes his bat to loop through the zone with a higher attack angle. Because of his posture improvements, Angelo now has more swing depth, can do damage against the high fastball, all while maintaining his production on pitches low in the zone. 

Last Day vs. First Day

Below is a side by side of his swings on K-vest. On the last day he maintains taller posture, whereas on the first day he was landing much more bent over. 

Side by side of his swings on K-vest. On the last day he maintains taller posture, whereas on the first day he was landing much more bent over

Data-Driven Approach

When it comes to training at Driveline, Angelo describes the athlete experience much better than I ever could: 

“The best part about Driveline is you get objective data that shows some of your weaknesses you need to work on. The trainers use the data and develop a plan centered around making you a better baseball player and maximizing your time at the facility.”

Our mission at Driveline is to make you the best baseball player possible, and we use technology and objective data to significantly enhance this process. If you train at Driveline, we will make sure to answer this question, “What are you working to improve, and how are we going to get you there?” Make the best decision of your career 👇


Interested in training with us? In-gym and remote options are both available.

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