Changes in Ball Weight: A Method for Athlete Individualization

By Stephen Hart, Pitching Coordinator

Through the years, we’ve come to note a development amongst sure athletes, particularly our newbie athletes: Many battle to carry out the pivot pickoff drill with the black plyocare ball.  Anecdotally, our coaches typically see or hear issues like this:

“It looks like I’m simply pushing it.”

“It simply doesn’t really feel easy in comparison with the inexperienced ball.”

“It seems to be such as you’re throwing darts.”

If that sounds acquainted, preserve studying…  

As a division, we knew we would have liked to create an answer that might permit athletes to throw extra comfortably whereas nonetheless providing an overload constraint to assist engrain new motion patterns.  

Introducing the three lb pink plyocare ball. 

We examined it with a choose few skilled athletes, they usually gave it nice reward and rave evaluations, however we knew that we would have liked to check it extra earlier than we rolled it out to the entire health club. Particularly, we would have liked to know the way it differed kinematically from the black and inexperienced plyos inside our drill set.


Throughout 30 athletes, 142 pivot pickoff throws had been collected in our movement seize lab for every ball sort (inexperienced, pink, and black). The desk beneath offers an summary of the descriptive statistics concerning the captures collected.

After the info assortment part of our investigation was accomplished, our sports activities science division examined kinematic and kinetic variations between ball weights within the following metrics:

  • Most shoulder exterior rotation
  • Shoulder abduction at max exterior rotation (MER)
  • Max shoulder horizontal abduction
  • Shoulder horizontal abduction at max exterior rotation (MER)
  • Elbow flexion at max exterior rotation (MER)
  • Most elbow varus second

Most Shoulder Exterior Rotation

Is there a big distinction between ball weights relating to most shoulder exterior rotation? In different phrases, when utilizing the inexperienced, pink, and black balls, do athletes have a tendency to realize a big distinction in layback?  Admittedly, we hypothesized that athletes on common would obtain much less layback with the black plyo, as it’s pretty frequent for athletes seemingly to exhibit a ‘pushy’ arm motion throughout pivot picks. 

Nonetheless, it might appear the ol’ ‘eye take a look at’ has failed as soon as once more. The information suggests, as seen within the density plot beneath, that there isn’t a important distinction in layback between any of the balls.

Maximum Shoulder External Rotation

Shoulder Abduction at Max Exterior Rotation (MER)

When analyzing shoulder abduction (elbow top in relation to the shoulder joint) at MER, there was additionally no important distinction between any of the balls. This may recommend that, regardless of the will increase in ball weight (of as much as 4 lbs), on common an athlete’s shoulder rotation stays on airplane with their higher physique, relative to the opposite ball weights. Put extra succinctly, athletes don’t display any significant distinction in elbow top relative to their physique at MER.  

Shoulder Abduction at MER

Max Shoulder Horizontal Abduction (SHA) and SHA at Max Exterior Rotation (MER)

As a short refresher, SHA, or scap retraction, is the angle of the humerus (higher arm) relative to the torso. Zero levels of SHA would have your higher arm in step with your torso, whereas a constructive quantity would point out that your higher arm is behind your torso (as proven within the picture beneath).


With this, we’ll first study variations in max SHA (scap retraction, in layman’s phrases).  Which means, all through the length of the throw, how far behind the physique does the athlete’s higher arm journey? From our dataset, max SHA is an important metric and (one among many) sturdy predictors of throwing velocity.  A doable rationalization for that is that a rise in max SHA, which seemingly creates a rise in SHA at foot plant, creates a better stretch-reflex throughout the pectoralis and deltoid muscle teams and better vary of movement to speed up the baseball.  

From our dataset, proven within the scatterplot beneath, on common athletes show a rise in throwing velocity as the quantity of SHA (scap retraction) at foot plant will increase.    

Pitch Speed vs Shoulder Horizontal Abduction

When analyzing max SHA throughout all ball sorts, we discovered a big distinction between all three balls. When wanting on the density plot beneath, on common there was a gradual improve in max SHA as ball weight decreased. The typical max SHAs for every ball sort had been 20, 25, and 29 levels for the black, pink, and inexperienced balls, respectively.     

Maximum Shoulder Horizontal Rotation

Subsequent, let’s transfer on to SHA at MER. With this metric, we’re analyzing, in layman’s phrases, the next query: When the athlete achieves max layback, how far behind their torso is their arm? We discovered some variations. Particularly, whereas there was no important distinction between the pink and black balls and no important distinction between the inexperienced and pink balls, we did discover a important distinction between the inexperienced and the black balls. Such a big distinction will be seen within the density plot beneath.  

Shoulder Horizontal Abduction at MER

This may point out that, on common, athletes performing pivot pickoffs with the inexperienced plyo have extra SHA at MER than these throwing the black and pink plyos. Whereas the worth remains to be destructive (higher arm in entrance of torso at MER), athletes throwing the inexperienced plyo exhibit a extra favorable MER place when SHA particularly. Oftentimes when athletes throw the black ball, they have an inclination to exhibit a extra elbow dominant (suppose throwing a dart) throw. This extra destructive SHA at MER worth reinforces these observations..     

Elbow Flexion at Max Exterior Rotation (MER)

Elbow flexion is used to explain how bent an athlete’s throwing arm is. Making a proper angle along with your elbow is 90 levels. Performing a bicep curl motion will increase the angle to over 90 levels, whereas straightening the elbow decreases the angle to below 90 levels. Not surprisingly, elbow flexion at MER is describing how bent the athlete’s elbow is at max layback. When wanting on the information, we discovered no important distinction between the pink and the black balls. Nonetheless, there was a big distinction between the inexperienced and pink and between the inexperienced and black balls. Which means athletes on common exhibited a better diploma of elbow flexion at MER with the black and pink balls in comparison with the inexperienced ball.

Elbow Flexion at MER

It ought to be famous that whereas there could also be a big distinction between the inexperienced and pink/black balls, this distinction could also be negligible when it comes to throwing velocity efficiency. Once we have a look at max elbow flexion because it pertains to mound throwing velocity throughout ranges of 70 – 96+ mph, there appears to be a candy spot someplace between 105 – 125 levels. From the picture beneath, we will see a gradual taper of throwing velocity as max elbow flexion is beneath 105 and better than 125.  

Pitch Speed vs Max Elbow Flexion

It ought to be famous some pitchers who throw at an elite velocity might fall exterior of those elbow flexion ranges, however on common the vast majority of elite throwers appear to fall inside someplace between 105 – 125 levels.  

So, whereas it might appear that on common throwers exhibit much less max elbow flexion at MER with the inexperienced ball in comparison with the pink and black balls, the quantity of elbow flexion they do create at MER appears to be inside a desired vary, nonetheless.   

Most Elbow Varus Second

The utmost elbow varus second describes the quantity of medial torque (measured in newtons) the elbow joint is uncovered to all through the throw (often occurring round MER).  When wanting on the information, there appears to be a big distinction in max elbow varus second between the inexperienced and black balls, whereas we discovered no important distinction between the pink and black and between the inexperienced and pink. 

Elbow Joint Movement MAX

It’s doable this important distinction between the inexperienced and black balls could also be defined by the rise (~ 2lbs) in ball weight.  

Dialogue and Implications

We had fairly just a few surprises and takeaways after we examined this information. Before everything, our preliminary speculation appeared to be improper in that MER, or max layback, on common was unaffected and never considerably totally different between all three balls. Naturally, there shall be some athletes who might battle to realize layback with any ball, primarily based on variables resembling power ranges and familiarity with every ball or drill, but it surely appears incorrect to imagine that an athlete will exhibit a ‘pushy’ arm motion with much less layback by throwing a ball 2 lbs or heavier. I feel we may attain the same conclusion concerning shoulder abduction, or elbow top, at MER.

I imagine an attention-grabbing dialogue might be had concerning SHA (maximally and at MER), elbow flexion, and most elbow varus second.  

When discussing max SHA, or scap retraction, athletes on common achieved a better diploma maximally as ball weight decreased. This may occasionally point out that athletes who battle to realize an enough diploma of scap retraction might profit extra from throwing the inexperienced ball as in comparison with the pink and black. Sooner or later, I imagine these outcomes might warrant additional investigation to determine if this relationship between scap retraction and ball weight inside the pivot choose drill continues whereas throwing the lighter plyos (blue, pink, yellow, and grey). This might have additional implications for program individualization.

Moreover, this investigation confirmed that athletes throwing the inexperienced plyo held their scap retraction a bit longer into MER when in comparison with the pink and black balls. In different phrases, athletes throwing the inexperienced ball displayed much less of an elbow dominant (suppose dart throw) sort throw. This relationship can seemingly be partially defined by athletes attaining a better diploma of maximal scap retraction with the inexperienced ball. 

When discussing max elbow flexion in isolation, as talked about beforehand, athletes throwing all three balls exhibited elbow flexion inside fascinating ranges. That’s to say, no matter ball weight, shows resembling forearm flyout didn’t appear to happen. That being stated, as a result of on common athletes throwing the black and pink balls did current with better flexion than the inexperienced, I feel there might be an argument made that athletes who severely battle with moving into correct elbow flexion positions may benefit from throwing the pink and black, barely greater than the inexperienced ball. A doable rationalization might be that the heavier pink and black balls permit athletes to really feel that extra flexed place barely extra clearly than they’ll with the two lb inexperienced ball.  

When analyzing most elbow varus second, we discovered a big distinction between the inexperienced and black balls, particularly. One can seemingly argue that this discovering may have some rehabilitation and on-ramp implications for athletes. Maybe there’s some profit to limiting the quantity of black ball publicity for athletes within the early levels of rehab and on-ramping, because the varus torques appear to be decrease for the inexperienced and pink balls. Then, probably afterward in this system, you could possibly step by step expose them to the upper torques imposed by the black ball as a way of throwing or torque development. 


Primarily based on the findings of this investigation, the next desk could also be used as a ‘cheat sheet’ for prescribing ball weights for the pivot pickoff drill primarily based on particular athlete shows. As a reminder, these are simply suggestions that can be utilized as a place to begin. Particular person athlete responses might warrant sure ball weight prescriptions.

        **Make sure you seek the advice of physician or doctor concerning rehabilitation throwing**


The outcomes from this investigation are actually attention-grabbing. To me, I feel it actually exemplifies that athlete individualization doesn’t have to return within the type of 30+ drills or drill variations.  Generally athlete individualization can merely come right down to ball weight used. The desk above, when used as a place to begin, reveals that there’s utility for all ball weights. And, like all issues, every ball is a software that deserves a spot in our teaching software field.


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