New ASMI Study on Youth Pitcher Injuries


#1

Drs. Andrews and Fleisig of ASMI have a new study out, “Risk of Serious Injury for Young Baseball Pitchers : A 10-Year Prospective Study”, just published in the February 2011 issue of the American Journal of Sports Medicine.

Among other conclusions, they “recommend that pitchers in high school and younger pitch no more than 100 innings in competition in any calendar year. Young pitchers who have not developed should be limited to even less.”

http://ajs.sagepub.com/content/39/2/253.full.pdf+html


#2

Thanks. Takes a few minutes to go through all six pages, but worth it.


#3

Really interesting read. What I am interested in though is not only the number of innings pitched in a calendar year, but also the time with which they were spread out.


#4

I found it interesting that the slider causes more concerns than the curveball. It seems to me the youth that throw the slider are the better athletes/pitcher. In our local LL and TT experience, many kids play with and throw the curveball (though rarely effective), but my son is the only one with a slider, and he’ll only throw this to a LH hitter in the middle of the lineup.


#5

???
Why?


#6

I think that the common misconception about the curveball is that you have to snap your wrist, which you don’t. This causes an excess of stress on the elbow. The slider you do have to snap your wrist, and it is a very stressful pitch for the arm. Look at the number of people who threw a slider and have had to had arm surgeries.

JD, maybe he is saying that he doesn’t want to stress his arm too much, so the pitch is used sparingly.


#7

I think that the common misconception about the curveball is that you have to snap your wrist, which you don’t. This causes an excess of stress on the elbow. The slider you do have to snap your wrist, and it is a very stressful pitch for the arm. Look at the number of people who threw a slider and have had to had arm surgeries.

JD, maybe he is saying that he doesn’t want to stress his arm too much, so the pitch is used sparingly.[/quote]

Why only LH hitters in the middle of the lineup . . . at his level, his two-seamer is good enough to get rest of the hitters out. We found out last year that his two-seamer moved away from the LH hitter into the hitting zone, and he gave up several 150’ RF bloopers that went for hits. Although their were only two LH hitters who connected on his two-seamer, we discovered the slider worked well against them and gave the LH hitters problems. He tried the slider and it moved into the LH hitter, taking away the LH hitters advantage. It’s not a true slider, since he throws it like the FB and only changes the grip, but the ball moves about 4" and is enough to keep the LH hitter honest. If the kid is not a good LH hitter, he wouldn’t use the slider since the two-seamer is good enough. As it does add more stress to a young arm, I decided to use it sparingly until he’s much older.

I should also add, he was 10 last year, and the slider was added primarily to get two very good LH hitters out. He also threw a very good knuckle curve, but only used it a few times during the year to keep the best RH hitters honest.

At this time the plan for this year is for him to throw 6 each sliders and knuckle curves during bullpen sessions, twice a week before the season and once a week during the season, and then a total of four to six each in game situations. For the most part, he will stay with the two-seamer until HS.


#8

I’m not clear why a slider is automaticallly considered more stressful than a curve. From what I’ve read from NPA you set the wrist angle between a curve and a fastball and unlike what many teach, you pronate through the pitch. (not twisting or supinating). So is it the way that some may throw a slider that is causing concern? I found this clip on Mythbusters with Clemons showing how he throws his slider and it definitely doesn’t look like he’s twisting/supinating/snapping, it looks like he’s pronating. Am I missing something here?


#9

[quote=“RJ35”]I’m not clear why a slider is automaticallly considered more stressful than a curve. From what I’ve read from NPA you set the wrist angle between a curve and a fastball and unlike what many teach, you pronate through the pitch. (not twisting or supinating). So is it the way that some may throw a slider that is causing concern? I found this clip on Mythbusters with Clemons showing how he throws his slider and it definitely doesn’t look like he’s twisting/supinating/snapping, it looks like he’s pronating. Am I missing something here?


I was always taught to snap with my slider, which I stopped throwing my senior year of high school when my arm began to hurt and the slider seemed to exacerbate the issue. Mine would move more than 4 inches though, of that I am sure. My catcher used to say if he wanted a ground ball he would call, haha.


#10

The reason the slider is condidered hard (the hardest) on the arm is because it combines the forces of a fastball (the slider is a velocity pitch) with supination.


#11

Roger you say people supinate when they throw the slider but is that the only way to throw it? In the Clemons/Mythbuster video I posted it sure looks like he’s pronating but again maybe I’m missing something. On page 42 of “The Art and Science of Pitching” House discusses presetting grips on breaking balls and change ups and says that the hand will pronate palm side out on all pitches after release point. That seems to be how Clemons threw his slider, with pronation. So if thrown that way why would it be harder on the arm than the curve?

As for throwing the slider with “fastball speed”: Could it be the slider travels faster than a curve because you are putting more force behind the ball (outer half of the ball) when throwing a slider than with a curve.

So in general, arm speed being equal

Fastball = fastest because force (hand) applied directly behind ball (no wasted force)

Slider = a little slower because force is applied on outside half of ball so some force is “wasted”

Curveball = slowest because force (hand) is on the side of the ball so more enery is “wasted”

And finally if pitchers slow down their arm to throw a curve and it’s not a big deal then why is it a problem when pitchers slow down their arm to throw a change up? (assuming the change has movement, depth and fade) Not trying to be difficult here just really trying to get some more detail on throwing breaking balls.

Thanks.


#12

RJ 35 wrote:
"And finally if pitchers slow down their arm to throw a curve and it’s not a big deal then why is it a problem when pitchers slow down their arm to throw a change up? (assuming the change has movement, depth and fade) Not trying to be difficult here just really trying to get some more detail on throwing breaking balls. "

Perhaps I am confused here, but I read in the study that the change up had the least amount of torque on the elbow. What I take from the study is that a slider is harder on a young arm than a curve, followed by the fastball, with the change up being the lowest stress pitch. This follows my current understanding of the bio mechanics. Am I missing something related to the change up?

I too am trying to get as much info as possible on breaking balls, because I am coaching 9-10 year olds. Some of whom play travel ball all year around and have been taught breaking balls from others. I am really trying to limit the use of breaking pitches in little league, but before I tell a pitcher to stop doing something he has already learned, I’d like to have as much info as possible.


#13

Hey GiantsFan,

Sorry for the confusion. The “Problem” I’m referring to in that paragraph is with hitters supposedly picking up a pitchers change-up because he is slowing down his arm, not a bio mechanical problem. Just wondering why that theory doesn’t then transfer to the curveball. If pitchers slow down their arm (don’t throw with same arm speed as fastball) to throw a curve why doesn’t that tip the hitter that a curve is coming?


#14

I’m not talking about actively supinating into release but presetting a supinated position (45 degrees from fastball position) and maintaining that through release after which the hand/forearm will pronate. From the point of maximum external rotation up to ball release - when all the forces kick in - the hand/forearm would be in a (45 degree) supinated position.


#15

Roger,

I don’t mean to drag you into a steaming pile of minutiae. I’m just trying to fully understand why a slider is considered harder on the arm than the curve.

So holding the 45 degree position to throw a slider is harder on the arm than the 90 degree position to throw a curve? Do you know why that would be? Just harder to maintain the 45 degree angle than the 90 degree?

I know the slider is a velocity pitch wihich leads people to say it’s harder on the arm but is the fact that it typically has more velocity than a curve, arm speed related or due to the fact that with a slider more force is applied behind the ball (even though off center) than with a curve?

I guess I’m asking aren’t pitchers taught to use the same arm speed on all pitches? Fastball, change up etc so it’s harder for the hitter to pick up the pitch.

And finally, if a pitcher can get sufficient movement from just throwing the outside half of the ball ( no supination, more of a cutter) would that be easier on the arm than a curve or slider?

Thanks


#16

[quote=“RJ35”]Roger,

I don’t mean to drag you into a steaming pile of minutiae. I’m just trying to fully understand why a slider is considered harder on the arm than the curve.

So holding the 45 degree position to throw a slider is harder on the arm than the 90 degree position to throw a curve? Do you know why that would be? Just harder to maintain the 45 degree angle than the 90 degree?

I know the slider is a velocity pitch wihich leads people to say it’s harder on the arm but is the fact that it typically has more velocity than a curve, arm speed related or due to the fact that with a slider more force is applied behind the ball (even though off center) than with a curve?[/quote]
More force is applied behind the ball with the slider and that means more of the force applied to the ball is used to accelerate the ball than to spin the ball than with the curve. The ball provides more resistance to the forces you apply to accelerate the ball than to the forces you apply to spin it. Of course, supination figures into things as well because the amount of supination determines the amount of torque on the elbow as the upper arm internally rotates while the hand/forearm maintain that preset angle. It also determines how much pronation will occur after ball release.

(This is based on stuff I’ve read. I have no way to prove it.)

Yes, they are. Whether or not that truly happens is not clear. There may be slight differences accoring to ASMI. But it’s still desirable to try.

Depends. Control is going to be more difficult and if that results in the pitcher trying to manipulate the arm to compensate, that could conceivably be worse than throwing a slider or curve.


#17

WHOA NELLIE!!!
What I’m seeing here is a lot of confusion and a lot of misinformation regarding the slider, the curveball and breaking pitches in general. So let me put my 75 cents’ worth into the discussion.
When I learned the slider, my pitching coach—an active major league pitcher who threw a very good one—told me, “Throw it like a curve, but roll your wrist, don’t snap it.” It’s that simple. The wrist action is something like a chef flipping a pancake or a crepe, so when you throw that pitch you actually have to ease up on it vs. what you do with a curveball. I threw my curve with a sharp karate-chop wrist snap, so in familiarizing myself with the slider I had to learn to ease up on it. And what I got with that slider was a sharp late break—it would come in there looking for all the world like a “fast ball” (which, actually, I didn’t have), and then it would suddenly break—not a big break, but very sharp, and it threw the batters’ timing off something fierce. In fact, a lot of pitchers who have been having trouble with the curveball will do very well with that slide piece.
Now, about pitchers who slow down their arm speed when throwing any kind of changeup—didn’t anyone ever tell them that this is one of the cardinal sins in baseball, a no-no if ever there was one? That was another thing my pitching coach told me, way back when—you have to throw all, and I mean all, of your pitches with the same arm motion and the same arm speed if you don’t want to telegraph them. otherwise you might as well yell out to the batter, “Hey buster, here comes a changeup” or “Here comes a—” whatever, thus giving them time to get set for something they can blast over the fence, out of the ballpark and into the kitchen window across the street! YOU JUST DON;T DO THAT. Not if you want to win the game…and if you want to last in the major leagues.
And speaking of changeups—that same pitching coach told me that just about any pitch can be turned into a nice changeup. He demonstrated a few of them for me, and I grabbed a couple of them, worked them up and added them to my snake-jazz repertoire. It all has to do with the different grips one can use, or holding the ball further back in the hand or further forward, or both. But you absolutely have to throw everything, and I do mean everything, with the same motion and the same arm speed—I can’t emphasize this too strongly. And you have to move the ball around—high, low, inside, outside. and stay away from the middle of the plate. By the way, I was one of those infuriating, exasperating sidearmers who used the crossfire extensively—that’s a beautiful and deadly move that works only with the sidearm delivery—and that gave me three times as many pitches, much to the discomfiture of the opposing batters.
Okay, That’s my seventy-five cents’ worth (rampant inflation, you know). I hope this clears up some of the confusion. :slight_smile: 8)