When ASMI’s weighted-ball study Biomechanical Analysis of Weighted-Ball Exercises for Baseball Pitchers was released, we were excited for many reasons. One of the big reasons was that we would be able to replicate this study.
We wrote about that study at length in our article Weighted Baseball Research and the Data Supporting Their Use. But one area of the paper stood out to us, which we expressed in the above article:
“The velocities of both the mound and crow hop throws are also not what we would consider elite velocities. This can partially be explained by the sample size with more high school athletes (18) than college (7). Therefore there may be differences in these findings if it was replicated with pitchers who throw 90+ off the mound.”
The researchers found a small but “statistically nonsignificant” increase in elbow and shoulder torque when pulling down (1.5 and 1.4 Nm respectively) with a fairly large increase in velocity between the two. (Pulldown throws were 7.8 mph harder.)
But the velocities of both were at the lower end of what we normally see in our gym population, mainly because we see more professional than amateur athletes.
To recap, below are the numbers from the ASMI study.
Since we see firsthand some of the differences in dealing with athletes who throw at sub elite (under 85 mph) and elite (over 85 mph) velocities, we hypothesized that the findings of our own study would differ in some way from the findings of ASMI’s study.
Our hypothesis claimed that we would find pulldowns to be more stressful than the ASMI study because of higher velocities.
While we do incorporate throwing weighted balls off the mound at high intent in our program, we do not do so for every athlete. Therefore the comparison that we are looking at today will be pitching a 5-oz ball off the mound to throwing a 5-oz ball in a pulldown.
If you’re curious how Plyo Ball ® velocity stress relates to pitching, you can find that study here.
Note: The ASMI study referred to the running throws as “flat-ground running throws” while in-gym we refer to them as pulldowns. For the rest of the article the running throws will be referred to as pulldowns
The ASMI study had 25 pitchers (18 high school and 7 collegiate pitchers) who had previous experience with a weighted-ball program throw. The exercises and ball weights (4-7 oz) were randomized for each participant.
In comparison, our sample sizes consisted of 12 gap-year college athletes and 13 college athletes. We did not have athletes pulldown and throw off the mound in the same day. We simply collected the data as it fit into each athlete’s schedule.
Each athlete completed all 3-7 oz pulldowns in our standard programmed ball order. It’s important to note that both mound and pulldown throws in the ASMI study were completed at random.
Similar to the ASMI study, we were looking at the three fastest throws with a 5-oz ball from one pulldown session and comparing them to the three fastest throws from one bullpen session. Similar to previous blog posts, if there were multiple throws that qualified as the third fastest pitch those numbers were averaged.
We used the MotusBASEBALL Sensor for our data collection.
What Did We Find?
Our results ended up being incredibly similar to the findings of the ASMI study despite faster velocities.
All of the data can be found here
Both ASMI’s study and our internal study revealed pulldowns as being more stressful than pitching off the mound, but only by a small amount.
Like we mentioned earlier, these results were surprising because the velocities that we had at Driveline were much higher than the ASMI study.
Our data was a fairly even split between college or gap-year athletes (12) and professional (13). This would account for the main reason of the increase in velocity since the ASMI study included 18 high school and 7 college pitchers.
One of the main differences in the ASMI study compared to ours was a larger spread between mound and pulldown velocities than we usually see. Our results of pulldowns being 5.5 mph faster are in line with the average 5.35 MPH difference we saw this past summer.
Though each athlete in the ASMI study had previous experience with weighted balls, it is unknown if they were still in a program when participating in the study. Also they threw 3-7 oz balls in a random order, which is our best guess as to why the spread was larger than expected.
We also saw that the pulldown velocities had a larger standard deviation than pitching off the mound, which would be expected.
Looking closer at the data, we can also see that the mStress is higher off the mound than it is pulling down. This should be unsurprising considering the pulldowns were, on average, thrown 5.5 mph faster, but the stress is only slightly more stressful.
The Rˆ2 between pulldown and mound velocities was 0.66, which is very close to the 0.7 Rˆ2 that we saw in our summer data.
This isn’t enough information, or a large enough sample size, to make definite claims about pulldowns. But the data speaks to the fact that we don’t understand why a running start would allow for much faster velocities at a relatively small increase in stress.
Other Motus Data Points
Very surprisingly, we found slower-arm speed with pulldowns when compared to pitching off the mound. We aren’t sure why this would happen, but it most likely is the result of pulldowns having much greater linear momentum when compared to pitching off the mound.
We don’t believe that this means that each pitcher should try to move as fast as he can down the mound. Though pulldowns and pitching are similar, we wouldn’t want to reach for that conclusion until we compared pitchers off the mound moving as fast as they can down the mound to pitching regularly.
Lastly, pulldowns in this study were compared to mound velos, where the sole object is to throw are hard as possible in both. This is different than trying to organize your body to pitch off the mound to throw hard, accurately, and with offspeed pitches.
The pulldown throws also had a different arm slot and more external rotation when compared to throwing off the mound. Arm-slot differences may be caused by different trunk positions. Max external rotation is measured in relation to the ground, so some of the differences may be from throwing off a mound compared to flat ground as well as any changes in forward trunk flexion. We would need more data than available to see exactly what caused the changes.
A second important question that we had after reading Biomechanical Analysis of Weighted-Ball Exercises for Baseball Pitchers was about the difference between the average and individual athlete.
“It is likely that some athletes in this study experienced significantly higher stress during the crow-hop throws while others might have experienced less stress during the crow-hop throws.”
That is what we saw with our athletes. Using mStress as our comparison metric we saw a pretty close split: 15 pitchers saw higher stress off the mound and 10 had higher stress while pulling down.
Oddly enough, if we did the comparison using the peak-stress measurement, then it flips: 16 pitchers had higher peak stress during pulldowns while 9 were higher on the mound. We still prefer the mStress measurement, but it goes to show how close pulldowns are in elbow stress when compared to pitching off the mound.
This is certainly interesting data, but the most important takeaway should be that both pitching and pulling down are quite stressful and they should be treated as such. Both studies do show that the averages are quite similar, but each individual athlete is going to be different from the next.
One of the 25 athletes even had a higher mound velocity than pulldown velocity. While that is very rare, we need to understand that those situations may occur and should be noted.
Is Pulling Down Similar to Long Toss?
It is admittedly the best comparison that exists to date. Pulldowns could most likely be compared to max-distance long toss, because both throws are often max effort. The trajectory of the ball would be different; pulldowns are thrown on a line while max long tosses often have a significant arc. But there are two vitally important differences between long tossing and pulldowns.
The benefit to long toss is autoregulation: you throw as far and as long as your arm and body feels up to doing. If you and your throwing partner are walking out and don’t feel it that day, then maybe you only throw 225 feet. If you both are walking out and feel great, then maybe you get to 275 feet.
In contrast, pulldowns are scheduled, max-effort throwing. A training program is built around an athlete being recovered and prepared to push his body to max effort.
Lastly, depending on arm strength, an athlete lobbing a baseball 225 feet as sub max effort is not going to be the same as pulling down.
Two biomechanical long-toss studies have been completed. One suggests that long toss is more stressful than pitching while the other suggests long toss and pitching create similar loads.
A third long-toss study found that pitchers, pitching coaches and athletic trainers often have different definitions of long-toss, which is problematic. Naturally, more research is needed.
Where Pulldowns Fit Into Training
As mentioned above, it comes down to programming. If the evidence suggests that running throws are slightly more stressful (barely) than pitching, then they should be treated as such.
They should be done within a program that is surrounded by solid warm-up and cool-down protocols focusing on keeping the athlete healthy.
The most important parts of doing running throws is doing them as part of a program—not doing them haphazardly or on a whim without proper recovery protocols. (In this instance recovery protocols are a broad term covering active recovery, recovery modalities, and scheduled rest.)
The quotes above are from Demonizing Weighted Balls – A Review Of Criticisms, and those points made are just as relevant today.
If you are curious about how we program pulldowns in our offseason training program, you can find our free 8-week offseason training guide here.
This article was written by Associate Researcher Michael O’Connell