Glenn Fleisig Says Pitching Injuries are NOT Inevitable

News flash for Sandy Alderson: pitching injuries are not inevitable. Neither is it so that every pitcher is on a time clock waiting for Tommy John surgery.

Further, flaws in pitching mechanics DO cause arm injuries and correcting flaws WILL prevent injuries.

But don’t take it from me — this is from the mouth of Dr. Glenn Fleisig, Research Director of American Sports Medicine Institute (ASMI) and the foremost expert on biomechanics of the baseball pitching motion.

Those were just a few of the topics covered in my discussion with Dr. Fleisig, which you can hear below:

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Joe Janish began MetsToday in 2005 to provide the unique perspective of a high-level player and coach -- he earned NCAA D-1 All-American honors as a catcher and coached several players who went on to play pro ball. As a result his posts often include mechanical evaluations, scout-like analysis, and opinions that go beyond the numbers. Follow Joe's baseball tips on Twitter at @onbaseball and at the On Baseball Google Plus page.
  1. Extragooey May 20, 2015 at 3:03 pm
    Is there a transcript somewhere? I’ll most likely read it. I can’t get myself to listen.

    I read a recent interview on Grantland with him and there were a couple of “chats” with him back in 2004 on baseballprospectus. So he’s been around and his message has been as well.

    In the Grantland piece what stood out was the study on kids 15-20 where it did show pitch count of 80 was a factor in elbow injury. This in light of our recent discussion on a post regarding 100 pitch limit on Harvey’s start against the Cubs. Also, the interview says that improper mechanics increases risk of injury. It doesn’t say that proper mechanics WILL prevent injuries as in nothing is definite.

    As I said, this guy has been around a while and i’m sure he’s been preaching for a while. If kids aren’t being taught what he advocates, well, then that’s sad. I certainly hope MLB organizations are following. But I can see maybe it’s just too late for some of the pitchers in the system. It may just be hard for someone to change mechanics unless it’s early as in just learning to pitch.

    Mark Prior was lauded as someone with flawless machanics that will never get hurt. Masahiro Tanaka was another one I’ve read with great mechanics. I don’t think there are absolutes to avoiding injuries in pitching. But you can probably lower your risks.

    • Joe Janish May 20, 2015 at 6:33 pm
      1. The 80-pitch data was done on 15-20-year-olds. Those bodies are still growing and different from mature men. So I’m not sure how you can apply that data to Matt Harvey’s situation.

      2. The 80-pitch data did not take into account the pitchers’ mechanics. So a 15-year-old with a pitching motion similar to Oliver Perez’s faulty mechanics or Mark Prior’s faulty mechanics are part of the data. The data also didn’t take into account pitchers who regularly engaged in long toss extending beyond 120 feet — the distance at which the elbow becomes at risk. Which in turn means the data itself is faulty, unless you assume that every pitcher pitches with the same mechanical flaws (maybe they do?).

      3. Mark Prior was “lauded” by WHOM? People who have/had absolutely no background in kinesiology / biomechanics / the science of body movement? Lay people such as Tom House and self-proclaimed “injury expert” Will Carroll? In fact, Prior’s mechanics were horribly flawed and the exact flaws can be easily identified by kinesiologists and biomechanists who regularly study the baseball pitching motion.

      4. Tanaka also has at least two mechanical flaws that led to his elbow injury. Whomever your sources are for “great mechanics” do not know their arse from their elbow (pardon the pun).

      4. It’s never “too late” to correct mechanical flaws. Most can be corrected in an hour or less, if the right person is providing the guidance.

      5. Dr. Glenn Fleisig is not a “preacher,” he’s a “scientist.” That means his statements are based on scientifically proven facts, research, and discoveries. “Preachers” pontificate on much less factual, more abstract theories, philosophies, and ideologies (such as religion).

      6. Proper mechanics WILL absolutely, positively prevent injuries. Will they prevent ALL injuries? Probably not, as nothing in the world is perfect or absolute. For certain, and without doubt, mechanical flaws do lead to arm injuries — there’s a direct line from kinesiological flaws to torn ligaments. Unfortunately we don’t have exact data about efficient / correct mechanics because there aren’t enough pitchers using proper mechanics.

      7. Do you have an advanced degree in body movement and/or have you done extensive research in kinesiology / biomechanics focused specifically on the baseball pitching motion? If so I’d like to hear more about your statement ” I don’t think there are absolutes to avoiding injuries in pitching,” and your reasoning behind it.

      8. When/if I have the time to write a transcript of the podcast, I will post it here as well as on

      • Extragooey May 20, 2015 at 4:53 pm
        Listen, I am agreeing with you more than disagreeing with you. I just don’t think it’s as black and white as you make it out to be. Of course mechanics has a lot to do with it. But how much is debatable.

        No, I don’t study body movements. But I do study human diseases as I am a scientist. I’m no stranger to empirical evidence, biological systems, scientific facts, etc. I do know that biological systems are never that black and white. Sure, there may be more of a direct cause and effect on an elbow injury from pitching mechanics compared to a disease like cancer. But it’s more likely multi-factorial with mechanics as a major factor.

        We can do a simple experiment. Pick 20 pitchers you think have perfect mechanics and 20 with flawed ones. Now, we’ll probably need to pitch count match to control it better, but since that’s probably impossible, we can just age match the two groups. Or innings match them if possible. We can revisit this in 10 years. My prediction, sure the group with perfect mechanics will have less injuries, but not as few as you’d think.

        • Joe Janish May 20, 2015 at 5:32 pm
          Here’s a better experiment, that isn’t even an experiment: pick 50 pitchers who have suffered a UCL tear or shoulder injury, and ask a kinesiologist to watch their motions on high-speed film and identify the exact flaw in the delivery that resulted in the injury. They’ll tell you how the correction could have been made to prevent the injury.

          Nothing in the world is black and white, and it wasn’t my intention to make it sound black and white. If you listen to the podcast you’ll hear much more than just the biomechanical aspects. Far too many people — and in particular, the people who make decisions every day at the MLB level — have this bleak outlook regarding pitchers and injury prevention.

          What is it that makes you so pessimistic about keeping pitchers healthy? Do you not see that nearly all pitchers have correctable mechanical flaws? Do you not recognize that the people watching them — pitching coaches — have absolutely no knowledge of body movement and yet they are the ones tasked with correcting mechanics? It’s like asking an ice cream salesman to work in the pits at an Indy car race. Or better yet, asking George Costanza to heal a beached whale.

          Yes you’re right that the situation is “multi-factorial.” But the only element anyone has been looking at is pitch counts. That’s it. The entire baseball world of cement-heads continues to count pitches as if there are only so many pitches in a man’s arm. NO ONE at the pro level has even considered bringing in a qualitative scientist to correct flaws (a few have consulted with quantitative scientists like Dr. Fleisig, but without the qualitative side it’s kind of useless). NO ONE at the pro level has even considered changing the routine of pitchers throwing a bullpen session the second day after a 100-pitch start, even though science has proven that doing so interrupts the healing process. VERY FEW pro pitchers and coaches will accept the fact that there are elbow exercises that can help prevent UCL strains and tears (every day I hear someone in MLB say “you can strengthen the shoulder but can’t do anything for the elbow”). Instead, ignoramuses theorize about kids needing to play more sports instead of focusing on baseball year-round (among other idiotic explanations). That’s the best MLB can come up with: to put all the blame on youth baseball. Well guess what? That doesn’t explain the MLB pitchers who go through second and third Tommy John surgeries.

          Are genetics a factor? Maybe. But genetics are out of our control. Meantime, training regimens, rest and recovery, and mechanics are within control — and until pro pitchers start considering all three of those elements under the supervision of qualified people, we’ll continue to see pitchers tear their UCLs and rotator cuffs on the current weekly basis.

        • Extragooey May 20, 2015 at 6:21 pm
          Well Glenn Fleisig himself commented on that one sport theory as explaining why more kids are hurt more. But before you jump on me here, he is saying there’s more time for more wear and tear due to poor mechanics.

          I’m all for post hoc analysis on why pitchers get injured. While post hoc analysis has merit, you need to make sure it doesn’t lead you down the wrong road. So Matt Harvey doesn’t have any of the inverted W or similar positions that lead to injuries. But he was “rushing” to get a few miles an hour more. This from Chris O’Leary, who claims he spotted this before Harvey’s injury. Perhaps, or was this “rushing” only noticed after the injury.

  2. Joe Janish May 20, 2015 at 11:03 pm
    Fleisig commented on the one sport theory because he was obligated to parrot his “boss” Dr. James Andrews, whose “position statement” from last year includes some “recommendations” that are based on hearsay rather than scientific evidence. Neither Fleisig nor Andrews will say anything publicly that might jeopardize their status with MLB, and I understand why.

    Forget the post hoc analysis. Consider that RIGHT HERE ON THIS BLOG several mechanical flaws have been identified prior to the injury (John Maine, Mike Pelfrey, Jon Niese, Jenrry Mejia, Johan Santana, etc.). You seem to be somewhat new here so you’re excused. And you don’t have the time/interest in listening to “The Fix” podcast so you’re excused a second time (we discuss pitchers’ flaws and their corrections every week, hence the title). I get it — I don’t like podcasts, either, but they’re the easiest and most efficient way I can get a scientist’s message out there. As soon as I hit the lottery I’ll find better ways to spread the word.

    Chris O’Leary is not a scientist and has no formal training nor education on body movement so I don’t pay attention to anything he publishes in regard to pitching mechanics.

    • Dan42 May 21, 2015 at 5:58 am
      Based on what I’ve read, and heard here and elsewhere, mechanic flaws overstress the body parts to various degrees, and insufficient recovery time due to bullpen sessions and/or overuse lead to serious injuries. Fixing either one would reduce injuries, but nowhere near what fixing both would be.
    • Extragooey May 21, 2015 at 10:49 am
      The issue is always causation vs correlation. Unless you do a well thought out analysis, you sometimes can’t distinguish the two. If you really have something, then you should be able to identify the pitchers with good mechanics that don’t get hurt. For instance, did you predict Matt Harvey’s injury? The list of pitcher you come up with that will not get hurt should be as impressive as the list of pitchers you’ve identified that will get hurt. Then your analysis has merit.
  3. Wohjr May 21, 2015 at 3:13 am
    I’m more interested in the relationship between mechanical flaws and effectiveness, which is sort of what I was getting at when I asked you months ago who you thought had “ideal” mechanics pitching today. Is it possible to be an effective, high-end major league pitcher getting it up there in the mid 90’s and still adhere to ideal biomechanics? I get there is a way to throw and not hurt your arm: is there a way to throw 96 with a killer slider and do it?
    • Extragooey May 21, 2015 at 10:44 am
      Bottom line is stress on the ligament. Bad mechanics add more stress. But just throwing harder does as well. Pitchers throw harder today than ever. Velocity does translate to effectiveness. I’d think you have to be gifted genetically to throw 96 with a killer slider. Others may be able to do the same, but with mechanical flaws to get there.
      • Dan42 May 22, 2015 at 3:45 am
        From what I’ve read and heard on this site, curing mechanical flaws does not hurt velocity, or pitch effectiveness. As for pitching in general, more velocity is not necessarily good for effectiveness since it can reduce ball movement, control, and how long a starter can stay in a game if maxim effort is overused.
      • Joe Janish May 22, 2015 at 7:48 am
        Effectiveness is almost always increased when mechanics are corrected / made more efficient. The idea that a pitcher won’t pitch as well if his faulty mechanics are corrected is a myth based on the fact that most of the people making the “corrections” (i.e., pitching coaches) have no idea what they’re doing when it comes to the science of body movement.

        Pitchers absolutely, positively do NOT have to use faulty mechanics in order to be effective, nor do they have to do something incorrect in order to throw with high velocity. In nearly every case, it’s quite the opposite — the pitcher can/would pitch better with safer mechanics.

        Extragooey — I don’t know of any mechanical flaws that help a human being to throw 96 MPH. Anyone who throws 96+ with a mechanical flaw would probably gain a few MPH by fixing the flaw.

        As far as a “killer slider” — science has so far concluded that one particular pitch (when thrown correctly) is not significantly more dangerous than another. There is some research suggesting that, if anything, the fastball puts the most stress on the arm while the change-up puts the least. But the difference is not significant enough to suggest that pitchers should stop throwing fastballs — not by a long shot. Personally, I’m a bit skeptical that curveballs and sliders aren’t more dangerous considering that it’s difficult to properly “release the elbow” on those pitches, but so far, the research states that neither pitch is any more stressful than a fastball.

        Regarding velocity, there have been many studies and research done into a specific MPH at which the elbow (in particular) becomes compromised. From what I understand — and I could be wrong — science still isn’t sure about a specific speed, and it may very well be related to genetics. AT THE SAME TIME, nearly every pitcher throws with some kind of mechanical flaw that can (and will) lead to a UCL tear, and not every pitcher engages in an elbow strengthening / maintenance regimen. So would, say, Matt Harvey have still blown out his UCL because he threw 98-100 MPH, if he had corrected his flaw, was diligent about keeping his elbow strong, AND regularly adhered to rest and recovery guidelines, AND refrained from long toss? We don’t know, and we won’t know until pitchers start doing these four things at a minimum.

  4. Bat May 22, 2015 at 3:56 pm
    Janish, did you see this article:
    It is lengthy, but good.

    What are your thoughts about the throwing program that Leo Mazzone advocates for in this article?

    • Joe Janish May 25, 2015 at 3:42 pm
      Nice piece, thank you for sharing.

      Mazzone’s “throw twice between starts” program is more or less the standard in MLB today, so the fact it’s mentioned as unique in the article is misleading. Assuming the program referenced in the article is the same as Mazzone wrote about in his book, then perhaps we can put some blame on Mazzone for MLBers ignoring rest and recovery guidelines, which in turn has contributed to the massive number of arm injuries we’ve been seeing.

      From his book “Pitch Like a Pro”:

      Greg Maddux | John Smoltz
      – He pitches on Sunday
      – takes Monday off,
      – throws on the mound on Tuesday and Wednesday,*
      – takes Thursday off,
      – pitches on Friday.

      Tom Glavine’s program was similar, but he played catch in the outfield on Monday and Friday.

      Mazzone’s assertion was that pitchers wouldn’t throw “hard” or “full effort” on those mound days, and that’s why it was OK. Well, I’m not so sure that works, because, for one, how do you throttle that from one individual to another? How do you decide what, exactly, is 80% effort vs. 60% effort? I guess by using a radar gun? But we generally don’t see pitchers throwing bullpens with a gun on them. Secondly, when a pitcher throws with less effort, his mechanics change — they have to, it’s impossible not to. So the pitcher isn’t really practicing what he’ll do in the game.

      The problem with Mazzone’s program is that regardless of whether the pitcher is throwing at full effort or less than, he’s still interrupting the healing process by throwing from a mound on the second day after a (presumably 79+ pitch) start.

      Mazzone DID implement a number of really good things, outside of the throwing program. He had all of his pitchers go through a solid and regular weight training program, and he was one of the few pitching coaches to understand that long-distance running did nothing for pitchers — that sprints are much better as throwing a pitch is an explosive act.

      The argument that “Mazzone’s pitchers didn’t get hurt using that throwing program” doesn’t hold water for many reasons. First, Smoltz blew out both his elbow and shoulder more than once, and he wasn’t the only pitcher to suffer major injury under Mazzone’s watch. Second, we saw Glavine, Mark Wohlers, Mike Stanton, Maddux, and others lose velocity instead of maintain (or gain). Athletes should get better, or at least stay the same, at least into their early 30s. Third, even if points one and two didn’t exist, it’s not scientific to conclude that a throwing program was what prevented injuries — it’s about as scientific as saying Wade Boggs was a great hitter because he ate chicken every day (or as scientific as Jim Kaat saying he played basketball in the winter and that’s why he was able to pitch over 20 MLB seasons). But that’s the problem with MLB — everyone puts more weight into anecdotal evidence and coincidence than actual, real, researched science.

  5. Bat May 25, 2015 at 10:20 pm
    Thanks for your thoughts Joe.