This article is going to start exploring the important role that upper body elasticity contributes to throwing velocity and the evolution of the human species.  That last part might sound a bit weird but when I was gathering information for this article I came across some pretty interesting research.  It suggested that the elasticity of the upper body provided the human species with a unique and important advantage allowing us to hunt and kill prey which in turn provided the nutrients (proteins and fats) required to develop bigger and better brains.  This advantage is our ability to throw.

Charles Darwin himself noted that the unique throwing abilities of humans, which were made possible when bipedalism emancipated the arms, enabled foragers to hunt effectively using projectiles.

This means that once we didn’t walk on our hands we could use our upper bodies to do other things like a throw.  This is great because compared to other carnivores humans are weak, slow and lack the natural weapons like claws and fangs used to hunt an animal.  We had to rely on the one thing we can better than any other species which is to throw rocks and spears.  This is how scientists believe that our caveman ancestors were able to hunt since we have been eating meat for the last 2.6 million years and killing large pray for the last 1.9 million years both of which predate hunting tools like the bow and arrow.

The ability to throw fast and accurate in modern times is important if you want to be a successful pitcher but back a couple of million years ago it was important for survival which made it a trait that was improved due to generations of natural selection.  Here is a quote from a study by Dr. Neil T. Roach who is an anthropologist from Harvard which confirms this idea.

“Throwing proficiency provided good throwing males an advantage over weaker throwers in gaining access to reproductive opportunities”

This quote contradicts the research done by Nike et al. (1996) stated that “Chicks love the long ball”.

Perhaps modern day females dig the long ball but cavewoman was definitely more interested in throwing ability. Here’s a link to the awesome commercial starring Greg Maddux and Tom Glavine.

Human Throwing Traits

In the study, I mentioned Dr.  Neil T. Roach notes that there are 3 distinct physical differences that separate humans from chimpanzees (our closest relative) which allows us to store and release more elastic energy.  Everyone has heard that chimps are much stronger than humans but throwing relies more on elastic energy in the upper body.  Check out this page and click on the video for more info from this study.

The three traits are:

1. Tall Mobile Waist
2. Less Humeral Torsion
3. More laterally oriented glenohumeral joint

Now there are exceptions to every rule.  The chimp in the 1996 classic “Ed” co-starting Matt LeBlanc could throw absolute gas!!!

If you’re asking why should you care about these differences between chimps and humans it’s because it gives us a better idea of what to look for when developing hard throwers.  Knowing what allows humans to throw hard might give us some ideas of what to look for when trying to determine what allows certain humans to throw harder than others.

Let’s look at each of these traits in more detail, today I am only going to cover #1 and the others for part two in this series.

#1 – Tall & Mobile Waist/Torso

You don’t need to pull out a ruler to see that the distance between the top of the hips and collarbone is much bigger on the left.  The relative distance would still be greater in humans if we took their overall height into consideration.  Notice the small gap between the hips and ribs on the left.

This extra space is what allows for hip and shoulder separation.  This has been a buzz term in the pitching world for years and if anyone asks you what exactly “hip and shoulder separation” is and how it adds to throwing velocity repeat this quote from Dr. Roach to make yourself sound super smart:

“tall, mobile waist of humans decouple the hips and thorax permitting more torsion rotation, in turn enabling high torque production over a large range of motion, which is needed to load the shoulders elastic elements.”

The elasticity we get from our trunk/core doesn’t come from a single muscle and its tendons but rather a series of muscles and tendons that run into one another which creates a “sling” or “serape” shown here.

Let’s look at how these muscles work during the initial phases of the throwing delivery.

“wind up” position

Here we load up the posterior sling/serape from the right foot to the left shoulder.  The picture below shows what this looks like in a golf swing.

If you were to go golfing and pause at this point in your backswing for a second or two you would lose some serious distance.  The pause would eliminate a lot of the elastic energy stored in these muscles.

“cocking phase”

As the body moves forward the anterior sling/serape gets loaded from the right arm to the left leg as they are extended and abducted respectively like we see in the picture below.

By extending the right arm and abducting the left leg these two body parts are moving in the opposite direction which causes the muscles and tendons to be stretched.  This is why we want a good amount of stride length – which depends on a bunch of other factors so don’t try to get 125% of your height just yet!!

“acceleration”

When the left foot hits the ground the left hip decelerates while the right hip continues to move forward and rotate.  As the back/right hip rotates forward in a counter-clockwise manner it unleashes the stored elastic energy between the hips and shoulders.  The stored energy in the posterior sling/serape from the “wind up” phase is also adding to rotational power by pulling the left shoulder in the same counter-clockwise direction.

See how Kimbrel still has his posterior sling/serape loaded this late into the delivery.

One of the many reasons this guy throws really, really hard!!

Here is how it is described in an article by Santana, McGill, and Brown.

“The core’s bigger mass “pulls” on the lighter right arm of the pitcher, much like a hand pulls on a whip”

In order to get the most out of this whip these authors go on to say:

“The Key to the acceleration phase is a stiff core so that maximum power can be transferred between hips and shoulders.”

This highlights the dual role that the core plays in that it transitions from a force producer, when it is being stretched and separated during the “cocking phase”, to a force transmitter in the “acceleration” phase when the muscles contract and produce stiffness.  If you want to learn more about the importance of core “stiffness” check out this article I wrote about how grunting can help you throw 5% harder!!

Stiffness & Separation Balance

The terms “stiffness” and “separation” contradict one another but the balance and timing between the two are vital to our overall success.  Without a stiff core, you can’t transfer energy efficiently but without the separation, you don’t have any energy and speed to transfer in the first place.

If we artificially try to produce too much separation in hopes of creating a bigger range of motion we might see a decrease in velocity if it isn’t synced up with the rest of our mechanics.  But if we try to be too quick and stiff we slow ourselves down and cut down on ROM needed to reach high velocities.  We should be looking at an ideal range and if you are at the low or high end of this range depends on other parts of the profile like mobility, strength, and limb length to name a few.  This is how Santana, McGill, and Brown sum it up:

“core stiffness is tuned with the appropriate muscle activity to best enhance the storage and recovery of elastic energy”

This is obviously complicated and teaching it to someone is even harder.  So let’s find out what kind of separation ability we are dealing with so that we can at least aim our efforts on the mound and in the weight room to meet the individual needs of the athlete in front of you today.

How to Test

If we remember back to the traits that Dr Roach listed which allowed humans to throw hard it was our “tall & mobile” waist that was the first of three distinct differences between humans and chimps.  So let’s test to see how “tall” and how “mobile” we are since everyone is going to be different.

How Tall?

By looking at the results of the seated vs standing height which we already discussed in the “anthropometric” article we can get a better idea of the distance from their hips to shoulders.

The seated height goes to the top of the head so this could be made a lot better if we subtracted the neck and head height.  It would be more like a tailor taking a measurement for the length of a shirt like we see on the right.

Since this distance is something that can’t be changed, unless you are dealing with young athletes, we have to work our mechanics around these results.

Mobile Waist?

Using a seated rotation test, which was listed in the “Mobility” article, is a simple way to get some great information.  Obviously, if you don’t have much ROM here you shouldn’t focus your mechanics around this power source but there are a lot of mobility drills that you can use to improve this score, namely t-spine extension, and rotation drills.

The limitation of this test is that the athlete is producing this ROM by using only their muscles which are called active ROM.  Passive ROM, on the other hand, involves the therapist applying an external force to move the athlete through their range of motion that goes beyond what the muscles can produce when moving slowly in this type of testing situation.

The distance that a therapist can rotate you past your active ROM to the point where your ligaments or joint structure stop can as give us some clues in regards to your elasticity.  Ligaments and joint structure are just a couple of the reasons why there might be a difference between the two types of ROM which is why it’s important that you have a professional therapist carry out these types of assessments.

If the guy in the picture could push on the stick and cause more rotation this would be passive ROM.

Even more, force is being applied when we pitch which is we should compare these clinical numbers to the ROM we see with a slow-motion analysis of the pitcher throwing.

This extra bigger ROM that happens when we pitch is due to the linear power we create when you move down the hill.  The same thing happens when we do a depth jump compared to a standard vertical jump.  The extra height that we drop in from causes more of a stretch making it more “elastic” than the standard jump.

If I’ve got you confused here check out this sports science video where that explains why PGA golfer Padrig Harrington can get more separation and distance when he uses a “Happy Gilmore” approach.   Go to the 5:15 mark of the video for their description.

Check out that extra “stretch”

This would be the case for long toss or Run n’ Gun type throws as well making it an appropriate drill for those who need to improve in this area.

Medicine Ball Testing/Training

Here are some tests that double as training exercises to help gain even more insight while providing a training stimulus to allow the athlete to improve their performance.

If we look at how fast or how far you can throw a medicine ball using a rotational motion we can see how efficient players are at storing and releasing elastic energy in a rotational fashion.

There are some pretty high-tech med balls out there that have sensors that tell you how much power you’re producing which is awesome because any time an athlete can have accurate and instant feedback you’re going to get better training effort when they try to beat their previous score.

If you don’t have $500 for a really fancy medicine ball you might have to use distance as a marker or hope that your radar gun can pick up the med ball’s velocity.  Either way, these tests require some practice in order to learn the skill so that you get better results.

These tests and their results will help us develop a better profile just like the various types of jumps did in the previous two articles with vertical and lateral jumping.

Med Ball Side Toss w/ Elastic Pre-Stretch
Here we promote the loading of the slings/serapes coupled with a rapid change of direction which emphasizes the stretch-shortening cycle

Static Med Ball Toss

Here we instruct the same as above but we make the athlete pause for a full 1 second before they rotate toward their target.  This method doesn’t use the stretch-shortening cycle.

Med Ball toss w/ Approach (aka Happy Gilmore)

The added approach speed seen below adds both momentum and stretch placing it further along the elastic end of the spectrum.

Please note that these are two different styles of med ball throws.  The first two are what I call a “scoop toss” while this last one is a “horizontal shot put”.  Be sure to compare the results using the same style of throw but use both during the training process.

Also, take note of how heavy the ball is since the heavier it gets the more we have to rely on muscles only while lighter balls allow for higher speeds which can cause stretch-shortening cycles to play a larger role.

So can get some useful information in two ways.  The first is to compare the scores and ratios between the pre-stretch, static and Happy Gilmore throws using the same weighted med ball.  The second would be to use the same type of throw and look at the scores using say a 4, 8 and 12 lbs med ball just like we look at our velocity difference between 4,5 and 6 oz baseballs.

The best part is that med ball throws are great training exercises that specifically target the muscles and movements that pitchers need to be more successful.

#2 – Less Humeral Torsion

Humeral torsion is a term used to describe the twisted shape of the humeral shaft.  You have probably heard of the term “retroversion” which is used to describe the same thing as humeral torsion, the only difference is the angle that you are measuring.

We want more retroversion and less torsion to create bigger ranges of motion.  Compared to chimps humans have 10-20 degrees less humeral torsion which allows for bigger ranges of motion like we see on the right.

Having larger amounts of external rotation has been shown to distinguish “fast” from “slow” throwers in previous research.  In 2001, Matsuo et al. published a study that reported harder throwers had 179 degrees of external rotation while the slower throwers were only able to demonstrate 166 degrees.

Here we can see Billy Wagner getting approx 180 of external rotation or “layback”, but we also have to consider the fact that he is going down the mound which makes this 180 closer to 200 which is why he was throwing 100 mph when it wasn’t as common as it is today.  The hard throwers in the study were only throwing about 85 mph.

Having more ROM when we go back into external rotation allows for more elastic energy to be stored and released as we transition to internal rotation during the acceleration phase.  When dealing with really fast movements, like throwing, elastic energy is what we want since it is made for speed whereas the power we get from muscles is designed more for moving heavy things at a slower rate.

The amount of torsion/retroversion that we have is determined partially by how much throwing that we do when we are young.  If we are able to keep our juvenile levels of torsion into adulthood we stand to benefit from this extra range of motion that naturally decreases as we age with what’s called anteversion.  To learn more read this great article by Eric Cressey called “Why Does President Obama Throw Like a Girl”

#3  – More Lateral Orientated Glenohumeral Joint

The glenohumeral joint (aka the shoulder) is classified as a ball and socket joint.  The “socket “portion is the glenoid fossa which is part of the scapula/shoulder blade while the “ball” is the head of the humerus.  In humans, this socket is facing to the side (aka laterally) while in chimps it is facing more upwards.  The picture below shows us the difference between the two with the human scapula on the left.

This does is creates a better angle to both produce and transfer force which is displayed in the picture below.  Having the arm abducted at 90 degrees from the body allows for more energy to be transferred from the rotating torso creating torque.  The approx 135-degree angle shown on the right from the chimp doesn’t allow for as much energy transfer from the torso when throwing but it is better for climbing, which for chimps is pretty important.  That’s evolution for you.

When the arm is at the 90-degree angle it puts the long axis of the humerus in line with the axis of the pectoralis major which acts as an internal rotator.  On the right in the picture below we see the muscle fibers of the human pectoralis major and how they run almost straight across at that 90-degree angle.

This really illustrates why we need to be near that 90-degree angle of arm abduction when we throw no matter if you throw “over the top”, “three-quarters”, “side arm” or even “submarine”.  Check out this article to learn more about this 90-degree rule and how throwing “over the top” increases velocity and stress on the arm.

Even if his knuckles are almost hitting the dirt he is still showing 90 degrees of arm abduction

Graeme Lehman, MSc, CSCS