Customized Pitching Mechanics – Elasticity of the Back Leg & Hip

In this article we are going to dig deep into how elasticity plays a role in throwing velocity.  You might want to do a quick review of the previous article that explains how elasticity works since it has been over a month since I published it.  This has everything to do with me watching a lot of playoff baseball but at least it has provided me with some big league examples of elasticity that you will see later in this article.

Elastic energy is vital to throwing a baseball and without it we wouldn’t be able to throw very hard at all. Every body part involved in throwing a baseball, which is pretty much all of them, uses elastic energy but I am going to focus on only four of the major ones:

  1. Loading of the back leg
  2. Landing on the front leg
  3. Rotation of the  hips and shoulder
  4. Rotation of the shoulder joint

Each one could be explored in-depth and be their own article.  In fact this article will just cover the back leg.  I am dedicating the next couple thousand words to the elasticity of the back leg for a couple of reasons:

  • It’s the initial power source for pitching – if we don’t get enough power here we sometimes try to make up for it further up the chain and this is a recipe for disaster (aka injury)
  • It is the one that we can consciously make the most changes with since it happens first and at much slower rate than the other body parts.
  • It’s the one I know the most about.

Elasticity  – The Back Leg

The power generated from the back leg in the direction towards home plate is important.  But how this power is optimally generated is going to be different from player to player based on their athletic profile.

In the previous article I discussed how this idea applies to high jumpers.  These athletes can be classified as “fast” jumpers if they use more elastic energy or “slow” jumper if they rely on the muscular strength.

The same classification can apply to pitchers when they load up their back leg.   Pitchers that are “fast” will quickly “stretch” their tendons and other connective tissues in order to maximize their ability to harness elastic energy.  Whereas “slow” pitchers will deliberately “wind up” the muscles of their back leg and hip to maximize the power they get from these muscles contracting.  Again everyone uses both elasticity and muscular power but you can lean on one more than the other.

I wanted to highlight the terms “stretch” and “wind up” because we already use them in the baseball world and I think that it’s ironic that they are common place because of the accurate way they are used to describe the action of the back the leg.

When runners on base we have to be quicker to home plate so we pitch from the “stretch” which ironically allows our body to rely on the stretch reflex when we quickly load and unload our back leg.

When nobody is on base we can pitch from the “windup” and take as long as we want to load up the muscles of the back leg and hip.  If you remember from the article on eccentric strength I used the analogy of a wind up race car to describe the action of loading up a muscle and how if we can wind up it more we will have more strength and power when it unloads.

Maybe someone a long time ago had a great understanding of muscle physiology and came up with these terms!!

If I’ve got you confused here is a reference table describing the two ends of the spectrum when it comes to loading up the back leg and hip.

Sport Sci Term Baseball Term Primary Energy Source Time Range of Motion*
“slow” “wind up” muscles > 250ms Big
“fast” “stretch” elastic <250ms Small*

The last column titled Range of Motion (ROM) looks at how much movement at the joint actually occurs.  Bigger movements generally require more time since they have to move further which places them in the “slow” category which rely’s more of muscle contractions.  This however is not always the case which is why I put an asterisk in this column.  The reason for this is that time is more of a factor.  If the ROM that the athlete uses can fit in that short amount of time they stands to benefit from elastic energy.  This is true of all of our internal rotator muscles and their respective connective tissues around our throwing shoulder as we go through a huge amounts of external rotation range.  But since this still happens in a very short period of time the amount of elastic energy is the primary driver of this fast action.  This is why bench press and throwing velocity don’t correlate very well.

The best example of this in regards to the back leg came from watching the playoffs this year in the Rangers and Blue Jays series.  The Rangers Tony Barnette has a ton of leg movement in his back leg but the speed that he drops and loads his back leg puts him into the fast/stretch category.


This clip above has him pitching with runners on base.  He gets a fast but deep leg bend allowing him to be quick to the plate in order to not let runners steal base’s but more importantly maximizing his ability to store and release elastic energy.

The clip below is what his mechanics look like when there isn’t anybody of base.  He adds some deception by coming to a pause at the top of his leg lift.  This may distribute the timing of the hitter while also increasing the amount of stretch that he gets by dropping in from a higher height.  barnette-windupThis extra height increases the eccentric load which in turn enhances the amount and rate of stretch that the connective tissues receives which can create more POTENTIAL power to be produced.  He can harness this POTENTIAL power because he has the strength to absorb and then redirect this extra energy.  If he didn’t you would see a longer pause at the bottom which would result in a less power being produced.  If you remember from the previous article I had a video clip from Dr. Behm talking about the stretch reflex and how sometimes if load up our muscles with too much force we can’t benefit from the elastic energy because it takes us too long to accept that force before trying to redirect it.  Here is the link to that video if you need a refresher – go to the 4:50 mark.

As a comparison let’s look at another member of the Ranger’s bullpen Matt Bush who has one the best “slow” back leg loading and unloading patterns in the game.

He is a clip of Matt Bush smoothly but powerfully loading his back leg before unloading his back leg and ultimately this fastball into Jose Bautista’s ribs.


You can only “stretch” so much

Before you go and start doing plyometrics everyday to build up your elasticity I wanted to touch on its limiting factor when it comes to pitching which is having to start from a static and stationary position. The lack of a running start means that you can only apply so much of a stretch to really maximize the amount of the elastic energy you can use to power your fastball.

Here are some examples to help illustrate my point.

The only time you ever see a pitcher get a running start is when Trevor Bauer is warming up with one his famous crow hop throws.  What I want you to look at is how quick his back leg loads and unloads compared to the second clip.


Trevor’s back leg loading method is definitely on the fast end of the spectrum even when he is pitching from the full wind up.  The amount of back leg bend is noticeably greater in the second clip.  He doesn’t need the bigger ROM when he crow hops because he has an approach which let’s get the same if not more elastic energy wihtou having to load up as deep.

Here are a couple of examples from the outfield.  Here we have two Cuban outfielders who have more than enough leg strength to throw the ball a mile even from a stationary position but when you can get a running start you’re best served to use the stretch reflex.

Here we see Yasil Puig throw a bullet with a quick and short punch of power from his back leg and hip.


He is able to throw the ball this hard with minimal amount of range of motion in the trail leg and hip because of a long and fast approach he had from playing back and charging this ground ball.  This momentum really allows him to load up that hip with a short but quick motion.


Next we have an example that doesn’t have much of a running start.  This bomb of a throw from Yoenis Cespedes uses more knee bend which results in a longer application of power from his back leg and hip muscles into his throw.


Because he booted the ball into the corner he is pretty much at a standstill but he is still able to get a little bit of stretch reflex with his right foot crossing behind his left before starting his throw.


Without much of a stretch reflex he is relying heavily on the strength of his muscles to get the job done.  Luckily for him he has some pretty strong legs.  Here’s proof of that strength in his famous “recruiting” video that his cousin/agent/trainer made of him during his days in Cuba.


Since throwing off the mound doesn’t allow you to get a running start this means that we need to have some baseline of good old fashion strength in the back leg to initiate the throw.  That being said we don’t need to turn everyone into power lifters since we don’t need really, really high levels of strength in order to utilize the fast stretch methods.  I will elaborate on this when I get into strength part of the athletic profile.

Testing Your Pitchers

This is where we start trying to figure out which way a pitcher should try to load their back leg in order to maximize the amount of energy that can potentially be transferred all the way up the kinetic chain to the baseball.

Lateral Jump Tests

In the last article I went over a series of vertical jumps that you can put an athlete through in order to determine if they are a “fast” or “slow” jumpers.  Each test placed an emphasis on either elasticity or muscular power.  When we look at the results and the ratio’s between the different jumps it can help give us a more accurate and larger profile of each athlete.

We can use this same thought process and make it a bit more sport specific by jumping laterally.  Which ever method allows you to jump the furthest should offer up some clues to how you might want to load up your back leg and hip.  All of these jumps require some practice to perfect the skill so play around with them 2-3 time per week for two weeks before testing in order to get a more accurate profile.

Static Start Lateral Jump – This one let’s us know what kind of strength you have by eliminating the elastic energy.  Load up on your back leg then pause for 1 second.  It is harder to get a pause here because of the balance component and without that control at the bottom there is no way to harness all of the power that you body could produce.  Practice first!!


What you can’t tell from this GIF is that he is waiting for my cue of “GO!” in order to start the jump.  This one needs the most control as a coach to get accurate numbers.  You can’t yell “GO!” until they are completely still for at least a full second.  The longer you wait the more the stretch reflex goes away leaving only the muscle to provide the power.  Don’t wait more than 5 seconds.  You also need to ensure that they don’t use any pre-stretch in their leg back watching them closely.  Our bodies know that we can get power for ourelastic connective tissues and because of that we will naturally want to cheat the test by getting a quick pre-stretch load by going down before up.

Play around with stopping at different joint angles to see which one suits you best.

Pre-Stretch Lateral Jump – This test falls into the same category as the depth jump because they both stress the ability to produce elastic energy.  This one however looks at how well you can apply force into the ground in a more lateral/horizontal fashion then send it back out to get the most lateral distance. Here you jump back laterally off your right leg onto your left leg before jumping out as far as you can.  It almost looks like a pitcher throwing from the stretch.


By jumping back you’re over loading the stretch of the connective tissues.  Each player can play around with the speed and distance they jump backwards during the loading phase.  Too fast and/or too far will result in a worse result because you need the strength to stop and redirect the loading of the muscles and tissues.

Counter Movement Lateral Jump – this is the cousin of the popular standard vertical jump which looks at a combination of muscular and elastic energy .  This jump allows for both types of power sources to be displayed.  As a coach watch the speed and depth each player natrually uses to get a general idea if they are “fast” or “slow” jumpers.


Here again we can play around with the speed and depth of the counter movement as we load into the back leg.  Try going fast and slow along with different ROM’s.

The results we can get from these tests are great and they get even better when you look at them collectively and build ratio’s.  This then becomes very useful information about how to build mechanics and training strategies.

Throwing Tests

Looking at the distances a player can long toss with and without a crow hop can be useful too.  The crow hop allows for an over-speed type of training effect which in turn means that elasticity will play a more prominent role just like we saw with the throws from the outfield.

We’ve all seen the guys that can bomb it out there during long-toss but can’t reproduce those same high levels of speed when they are throwing from a mound without an approach.  If when your athlete throws long toss without an approach and can only get 80% or less of their long toss distance with a crow hop then you can ecpect this athlete to be “springy”.  If the athlete can achieve 92% or more of their max long tosss distance without using an apprach then this athlete is more on the “strength/slw/windup” end of the spectrum.  These numbers didnt’ come from a fancy study but rather just my own observations.  Anicdoetal evidnce.

Finally I think we can just get our pitchers to play around with different loading patterns during bullpens.  It’s a good thing in my opinion to play around with mechanics and add variety and variability so that each pitcher can learn to adapt to different ways of throwing.  Obviously it will take time to sync up all the mechanics so don’t expect to see higher  velocities the first time out with any new loading pattern.

Graeme Lehman, MSc, CSCS



  1. Bobby

    Great article,
    You have an incredible understanding of throwing. I have a question as it pertains to pitchers. Do you feel running crow hop throws are good or should one stick to the back leg how it’s replicated on the mound. You mentioned that the back leg does 2 different things between a regular mound type throw and a running throw. I know some people popularize running velocity throws online and wanted to know you’re thoughts about it. Should the back leg be trained how it moves on the mound, thus getting rid of these running throws?

    • Graeme Lehman

      Thanks for the comment. I don’t mind the run n’ gun throws or even the max long toss with a crow hop but I do think they have their place. If someone is already really good at these types of throws then I think they should spend more time developing the ability to produce force from a more stationary position. But there are those that aren’t fast enough that can benefit from these over-speed type of throws. As a coach we need to get the right players doing the right type of training which sometime means making them do the drills they aren’t good at becuase we all revert back to doing the things that we are good at rather then things we need improving.

  2. Thom Krupar, PT, AT

    Great article guys. I like the high jumper analogy. There is an old book by Dwight Stone on high jumping styles (just as you mentioned) being fast or slow (strong). He basically said you can jump higher by either spending more (stronger) or less (quicker) time on the ground.

    • Graeme Lehman

      Thanks for commenting and I am glad that you enjoyed the article. If you don’t dig deep most people would assume that being “fast” is better than being “slow” but they can both work and it just depends on the athlete and their makeup/profile.

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