TRANSCRIPTION 🔗
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What's up, everybody. You're listening to the Strength and Knowledge podcast.
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I'm doctor Zach Baker, and I have with me today
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doctor Asher Roberts, one of our two sports residents here
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at R two P completing his March monthly research article review,
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and today we're talking about professional baseball pitchers elbow injuries
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and is there any utilization of jumping and force plates
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that can clue us in on their injury risk or
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potentially performance? And Asher, if you don't mind telling the audience,
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what was the actual title of the article that you
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gave and what led you to go down this route?
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Why was it appealing to you?
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Yeah, so the article is called what can a jump
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tell us about elbow injuries and professional Baseball Pitchers? And
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right now in residency, we're going through the elbow risk
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in hand and having done one of my clinical rotations
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with an MLB team or their minor league affiliates, this
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was actually an article that I heard mentioned a few
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times on that clinical rotation. People always just talked about
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it as like the jumping article, and so I wanted
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to delve into it and kind of see what it
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talked about.
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It's pretty cool how the variety that you can see
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force plates used in a sports performance world and in
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a rehab environment as well. I've seen it used in
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a variety of different ways at the collegiate setting, at
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the professional setting, some using it in a very basic
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form and just nitpicking maybe one or two different jumps
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and one or two different metrics within those jumps. And
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then you have some organizations that have sports scientists or
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people in the sports medicine field who are there solely
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to deep dive into not only the primary but also
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the secondary and tertiary metrics as well. So I love
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the force plates because you can make them as simple
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or as complex as you would like them to be.
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And this article, I think they took a relatively simple
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approach and we're able to find some interesting information. Asher,
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Can you talk a little bit about just what the
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design of the study was and how it.
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Was carried out. Yeah, so this was a case control study.
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They analyzed over five hundred pitchers over a five year
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span between twenty thirteen and twenty eighteen, all under one
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professional baseball organization. So we're talking guys all the way
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probably from major leagues down to their like low a
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guys rookie league all them, and basically what they were
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looking at was counter movement jump and its association with
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elbow injuries. So how the study worked was they had
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each picture go into the force plates and they performed
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six counter movement jumps, and really they were looking at
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three variables here e e RFD, which is ecentric rate
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of force development basically how fast do you produce force
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during the loading phase of the jump? AVCF which is
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average vertical concentric force basically, what is the average amount
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of force you're producing during that jumping part of the
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jump right after the loading phase. And then CVII which
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is concentric vertical impulse, which is impulse is that area
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under the curve, which is basically kind of your time component.
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You know, if you have relatively low impulse, it's going
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to be a very quick rate of force production, where
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if it's longer, you're going to be producing force over
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a longer period of time.
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So with the counter movement jump, and for those not familiar,
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it's just a basic vertical jump. One of the easiest
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things that you can track is just simply jump height
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with athletes. In this study, they're nitpicking a few different
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phases and a few different metrics associated with those phases.
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So they look at some components related to the eccentric,
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some related to the concentric, some having to do with
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just general force, some with that force
Load full transcript
that can be
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produced over time, and then also rate of force development,
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So kind of three different ways to look at how
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strong were powerful an athlete is in both an ecentric
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and a concentric component, which we know with throwing is
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very important to produce enough velocity to get the ball
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to the plate at the desired speed, but then also
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be able to control yourself and your body's motion after
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you release the ball. So Asher they went through six
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counterboom at jumps, they tracked ERFD, avcf CVII.
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What did they end up finding after they ran the
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tust Yeah, so basically over this five year period span,
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there were sixty one shoulder injuries and fifty one elbow injuries.
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And immediately they just kind of threw out that shoulder
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injury variable because they didn't find much correlation with it.
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But with the elbow injuries, they found a couple significant things.
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The first one was that ERFD was negatively correlated with
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injury risk, and the other that there was a correlation
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between the interaction between your a vertical concentric force and
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your concentric vertical impulse. So basically, depending on if AVCF
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was high and CVII was low, that would put you
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at risk, or if AVCF was low and cvi was high,
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you'd be at injury risk.
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So basically, if you had a mismatch between the average
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vertical force he could produce and your vertical impulse during
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that same timeframe. Correct and then with these what are
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things that you can actually take away from this? Why
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do they think that these were correlated to injury or
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had any association with injury? And I think once you
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talk through it, it sounds relatively straightforward. It's just a
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reminder of having a good strength conditioning foundation probably correlates
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very very well to injury risk profiling and also sports performance.
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Yeah, definitely, a lot of what they found was kind
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of more inferred. It's more like a working hypothesis. They
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just saw that like, hey, this is what the variable was,
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and this guy had an elbow injury. So they're kind
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of connecting the dots between the two and it does
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make sense how they connect them. Basically, if you have
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a low eccentric rate of force development and that's going
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to infer that you're not producing force very quickly during
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that eccentric phase, so you have an issue with producing
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force quickly. The idea with how that could lead to
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an elbow injury is if you can't produce force very
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quickly during the loading phases, you're going to be much
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more reliant on more upper body torque during a throwing
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motion because your legs aren't doing a lot of the work,
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which is going to obviously put more torque on those
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joints higher up the kinetic chain, leading to a higher
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risk of elbow injury.
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Yeah, and I think just to familiarize people with the
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throwing motion. After we end up releasing the ball and
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we go through that acceleration phase and we enter the
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deceleration and follow through phase, that is where that lead
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leg it has already struck the ground, our momentalness carrying
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us towards the plate, and now it's on that lead
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leg and our trunk and core to rapidly and efficiently
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decelerate our body. So if ERFD is low, that ecentric
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or decelerating component rate of force development is low, we
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have a lot of momentum carrying through our body that
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we're unable to control. So we're gonna have to find
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a different way to do so if the muscles cannot
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accommodate that. What else did they find in relation to
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the average vertical concentric force group or that vertical impulse group.
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Yeah, so basically they found that that mismatch puts you
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at risk and kind of makes sense. If you have
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it a high average vertical concentric force, that means you
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produce a lot of force. If you have a then
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a relatively low concentric vertical impulse, that means you're producing
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that very high amount of force very quickly. So, since
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throwing is a full body kinetic chain movement, if I'm
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able to produce a ton of force very quickly and
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my upper extremities can't control that force, then I'm going
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to be at risk for elbow injuries or really any
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injury up the chain.
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Yeah. Say, it's really shedding light on both components. There's
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just a force component to this and how much force
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can we generate concentrically and ecentrically, But then how quickly
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can we tap into that when we look at rad
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of force development, So how quickly can we get to
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our maximal force output? But then also do we have
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the ability to sustain that over time, or do we
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have to do that in a very short amount of time,
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which I always use the analogy of like two eighteen
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wheelers going down a hill, and you have one has
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a mile to stop and the other one only has
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five hundred feet. The one that has a mile can
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kind of pump the brakes the whole time and gradually
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close to a stop, it can dissipate that force over
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a long period of time. The brakes probably aren't going
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to wear out that quickly. The truck that only has
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five hundred feet to slow down, it's got to slam
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the brakes on and it may stop in time, but
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it's going to come at a cost to those breaks.
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And that's the same thing for our body. It's one
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thing to be able to have powerful muscles or in
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the truck analogy, powerful breaks, but it also is advantageous
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if we have the ability to tap those breaks as
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opposed to slamming them on immediately, so we're not dealing
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with potential cuff injuries or increased stress to adjacent joints
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that may have to compensate and take on more load.
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As sure anything else within this article that either they
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were able to infer or you were able to take
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away that you thought was
interesting or just relevant to
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clinical practice. Yeah.
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So the other interesting one was that relation between your
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low average vertical concentric force and your high concentric vertical impulse.
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That was kind of an interesting correlation there. I'm definitely
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not as high of an injury risk as if you
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have that very high amount of force and a very
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short amount of time. But what they hypothesize was if
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you produce relatively low vertical concentric force, but it takes
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you a while to produce that force, meaning that higher impulse,
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and basically there's going to be a much higher demand
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on your body for increased motor control and basically higher
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EMG activity is what you would see with these kind
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of pitchers. They have to use more muscles for longer
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to get there, so that's going to lead to basically
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a quicker fatigue with throwing. They're not as efficient, if
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you will, with their throws, so they have to put
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a lot more effort into them. And so if you're
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doing a very high pitch count and you're that kind
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of picture, you're probably setting yourself up for some kind
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of risk of injury.
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It forces you to be extremely mechanically efficient in that sense,
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and as you alluded to, that just takes significantly more
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coordination and just more calculated f As a PT asher,
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you work at our Frederick location. It is an outpatient
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sports med PT clinic. You get to see a variety
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of people. You get to see some high level athletes.
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You also get to see some youth athletes who are
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relatively untrained. When people come into the clinic and they
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are a pitcher and they're maybe potentially coming off of
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Tommy John or it's a less serious injury and they
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just have some general elbow or shoulder soreness, what are
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things that you think of that are worth looking into
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or worth training to supplement just a really good orthopedic
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plan of care,
meaning address the shoulder, address the elbow impairments.
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But now that you have this study, what are the
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things that you'll keep in mind either from a testing
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or an intervention standpoint.
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Yeah, so, I mean we already know that throwing is
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a full body motion, use the whole kinetic chain. I
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think this gives us as clinicians a couple of extra
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tools in our toolbox. If things we can look at
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too kind of tease out some other things that we
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can work on. Maybe when say, if someone's pretty acute
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with an elbow injury, hey, maybe we can get them
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on the fource decks, look at these variables and see, hey,
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is there a deficit with any of these, and start
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working on something there, teaching the body how to use
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and dissipate force effectively throughout not just the arm, but
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the legs, the core, all of that. Basically, this isn't
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going to give us all the information we need to
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determine if a picture's at risk of injury or if
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this is the reason that the injury happened. A lot
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of other things come into play. Your mechanics, genetics, You
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could just be a more lax person in general, you're throwing.
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Mechanics in general can put you at risk. But this
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gives us an extra thing that we can look at, see, hey,
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is there anything that's jumping out to us? When we
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put someone on the four stecks and have them do
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a counter movement jump.
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It's a good reminder that just being generally athletic and
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in good shape tends to bode well for athletic performance,
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even if there's not an immediate or exact transference between
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the athletic task you're doing and the sporting task that
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you're doing. Throwing is a largely rotational, horizontal displacement of force,
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transferring weight from one leg to the other. It's asymmetrical,
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it's unilateral. You have literally one part of your body
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doing the exact opposite of what its counterpart's doing. Your
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right leg and left leg are doing the opposite things.
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From a kinetic standpoint, one's going into flection, one's going
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into extension, one's going into er, one's going into R.
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But the counter movement jump is the opposite. It's a bilateral, symmetrical,
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vertical displacement activity, and it's pretty cool to show that
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even though they're drastically different movement profiles, you can take
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meaningful information from each one. So I think from a
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training standpoint, it also reminds me, hey, we need to
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do sports specific activity to prep them for the demands
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of the sport. But it is perfectly fine to do
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just some general foundation strength and conditioning when we're looking
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at strength development, power development, or we're just training energy systems,
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and maybe we're trying not to put the body through
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the same stresses that it's going to encounter. When they're
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pitching or when they're doing whatever their sport is. So
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just a friendly reminder that usually well rounded athletes tend
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to be very good at the sports that they play.
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Ash or any other takeaways from this or do you
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think we hit it all?
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I think we hit it all awesome.
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If you are listening and you enjoyed this episode, please share, like,
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and subscribe. You're listening to the Strength and Knowledge Podcast.
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This is doctor Zach Baker, doctor Asher Roberts. Thanks for listening.