The Real Reason Why Weighted Baseballs Increase Pitching Velocity, and Injury Rates

Weighted ball training programs have become a very popular tool for baseball players looking to improve their pitching velocity.

Unfortunately, the popularity of weighted baseball training has grown faster than our understanding of the science behind them.

Over the last several years, Lenny Macrina and I at Champion PT and Performance have teamed up with Dr. Glenn Fleisig and Dr. James Andrews at the American Sports Medicine Insitute to try to learn more about the safety and efficacy of weighted baseballs.

Over a series of research projects, we’ve learned a lot over the last few years. But, there are still many questions related to the safety, mechanism, and efficacy of weighted ball usage in baseball. 

We’ve learned that throwing weighted baseballs changes the stress involved on the arm

Dr. Fleisig examined the biomechanical effect of throwing weighted baseballs in a group of high school and college pitchers. 

The authors noted a significant increase in elbow varus torque (stress on the Tommy John ligament) when throwing weighted balls on flat ground with the run-and-gun technique compared to throwing off a mound. 

Okoroha showed a similar increase in elbow varus torque in a group of youth baseball pitchers throwing flat ground.  They documented a statistically significant increase in stress as the weight of the ball increased.

We’ve learned that injury rates are higher in baseball pitchers that perform a weighted ball program

Our study was the first to examine injury rates during and following a weighted ball throwing program.  

While we did show a 3.3% gain in pitching velocity, we also showed a 24% injury rate in high school baseball pitchers who performed a 6-week weighted ball program.  There were no injuries in the control group that did not perform weighted ball training and only focused on normal weight training.

And while we did show that velocity increased, it wasn’t in all the pitchers, and 67% of the control group also showed an increase in velocity just by basic throwing and weight training.

It’s important to note that we followed our players for the season after performing an offseason weighted ball program. We see far more injuries in the season after than while actually performing the weighted ball program.

We also think we’ve learned why we see both velocity gains and higher injury rates

More importantly, I really believe that we learned a lot about the mechanism of both the increase in velocity, as well as stress and injury rates, from weighted balls. I’ve tried to summarize this in some articles on the science of weighted baseball training programs.

We were surprised to observe a significant gain in shoulder external rotation range of motion (or layback). 

Pitchers in the program showed a significant gain of 4.3 degrees of shoulder external rotation after the 6-week program.  The control group did not show this change.  And we know from several previous studies that the amount of layback is correlated to both increased stress and velocity in baseball pitchers.

Weighted baseball training programs may be effective at increase pitching velocity, but they also increase shoulder motion, stress on the elbow, and injury rates

After we found that external rotation of the shoulder increased after performing a 6-week weighted ball program, our first thought was that we needed to study the immediate changes after throwing weighted balls to see if this was something that works right away or needs weeks of training to observe.

Which leads us to our latest study.

The Immediate Effects of Weighted Baseballs on Shoulder Range of Motion

In our latest study that was published in Sports Health, we wanted to see what happens to shoulder range of motion immediately after throwing weighted balls.

To study this, we looked at a group of 16 high school baseball pitchers with a mean age of 17 years old. We measured their shoulder range of motion before and after a weighed baseball training session to assess what changes occurred on that one day.

Because there are many different weights of baseballs used in the common training programs, we also wanted to see if there was a difference between the weights of balls used. So we broke the study into 3 different test sessions.

The pitchers came to our facility on 3 separate days to perform the 3 different training sessions:

  • Underweight baseballs using 2oz, 4oz, and 5oz balls
  • Overweight baseballs using 5oz, 6oz and 9oz balls
  • Extreme overweight baseballs using 5oz, 16oz and 32oz balls

Each pitcher threw 3 throws with each ball in 3 different positions:

  • Kneeling throws
  • Rocker throws
  • Run and gun throws
weighted baseball velocity program

So, in total, each testing session threw 3 throws from 3 positions with 3 different ball weights for a total of 27 throws. That’s not a lot for one session. People often do a lot more than that in reality.

Immediately after each throwing session, we measured their shoulder range of motion again. After just this small amount of time and throws, we didn’t expect to find many differences in range of motion.

This proved correct when we looked at players after throwing underload balls. There was no change in range of motion. This serves as a good baseline for the rest of the findings, the only variable we changed in the other sessions was the weight of the balls, so any changes we find can be attributed to the weighted balls themselves.

As the weight of the balls started to increase, so did our findings. With the overload balls of 6oz and 9oz, we started to see a change in shoulder external rotation range of motion, or layback. As the weight of the balls increased, so did the amount of external rotation gained from throwing. With the overload balls, external rotation increased by over 3 degrees, but with the extreme overload balls of 16oz and 32oz we saw an alarming increase in over 8 degrees:

Acute effect of weighted baseballs on shoulder range of motion

I can’t stress enough how important that finding was in this study. Lenny and I literally looked at each other while we were measuring range of motion and were shocked.

One thing to keep in mind with any research study is that these values are the averages of the groups. When you break down the numbers per person in the study, the results are even more valuable. Realistically, the level of intensity of the throws may alter the results. If a particular pitcher doesn’t throw with a lot of intensity, it could skew the data. This could happen with people that aren’t used to throwing weighted balls.

For the overload session of 6oz and 9oz balls, you can see that some players’ range of motion didn’t change much, but a trend towards this increase. For those that did increase, there were many that increased more than 5, 10, and even 15 degrees of external rotation, with an average of over 8 degrees:

weighted baseball training increases range of motion

So even though the 3.3 degrees mean change in external rotation was statistically significant, it could be even more clinically relevant than even this study suggests. I personally consider this 3.3 degree change to be the baseline, with many players increasing more than that.

When you look at the extreme overload session of 16oz and 32oz throws, the results are even more revealing. The large majority of subjects went up, and went up by a lot:

The effect of weighted baseball training

So again, while the mean of 8.8 degrees was statistically significant, the clinical implications are even higher, the majority of players increased external rotation by 10-20 degrees.

This finding is alarming and something that everyone needs to understand if you use or recommend using weighted balls to develop pitching velocity.

Throwing with weighted baseballs increases your external rotation rapidly by a lot. The heavier the ball, the more the range of motion increases.

But… But… But…

As with my past research, many people have read our findings and not been happy with the results. Perhaps the results challenge their bias and past beliefs? Or maybe they just don’t want to know the science.

So many people have tried to criticize our methods.

Remember, we have no bias. We are the scientific people trying to study these weighted ball programs. We do not profit off them (until you get injured!). We just want to know the science, we really have no preference as to what the data says. I’m as surprised as you are with the results.

I want to address the common things we hear about our studies:

  1. We included run and guns with a 2lb ball. Unfortunately, this is happening in the real world. Kids are doing this. I’m glad that some people think this is a little crazy, I kinda do too, but the goal of our studies is to assess the spectrum of programs that are out there in the real world. But please keep this in mind… there were only 3 throws with a 2lb run and gun. That’s not a big deal. That’s 3 throws out of 81, or less than 4% of the study. Let’s not throw out the other 96% of the study.
  2. Player’s weren’t prepared for a weighted ball program. This isn’t true. All players in our studies had been adequately prepared by performing a baseball-specific training program and a several week ramp-up throwing program prior to these studies.
  3. Player’s weren’t familiar with weighted ball programs. This may be true for some of the subjects, but not all. But again, we wanted to simulated the real world. You have to start training with weighted balls at some point when you first start a program.

I sincerely do not believe any of these factors are very relevant and certainly do not limit the clinical value of our findings.

Why Does External Rotation Increase?

shoulder external rotation ROM layback

I’ll start this section off pretty clearly: We don’t really know.

But, we have some very plausible educated guesses based on our scientific evidence.

To be honest, I was personally very surprised to see that external rotation increases from weighted balls. But now that we know this, it absolutely makes sense.

But why?

There are likely two reasons why external rotation increases after throwing weighted balls:

  1. Acute changes to the neuromuscular system
  2. Chronic cumulative damage to the musculoskeletal system

Weighted Balls Cause Acute Changes to the Neuromuscular System

The rapid gain in external rotation was surprising. I don’t think this typically represents significant trauma to the shoulder, like tearing the capsule or muscles (more on that below…).

What is most likely happening is that we are desensitizing the proprioceptors, the Golgi tendon organs (or GTOs), that are designed to detect stretching and fire our muscles to protect from overstretching.

These GTOs detect when our joints are getting to the end of their range of motion and trigger the opposing muscles to slow down the movement to protect yourself.

golgi tendon organ
Photo from Wikipedia

Desensitizing this mechanism can lead to increase mobility, but at what cost?

This is a defense mechanism within our bodies. Without it, our throwing shoulder and elbow are susceptible to more stress.

In the physical therapy and training worlds, we actually use this to our advantage at times. Plyometric exercises, dynamic stretching, and techniques like contract-relax all work on this premise.

When you stretch your hamstrings and feel looser immediately after, it’s not because your hamstrings got longer after a few seconds of stretching. That structurally doesn’t make sense. It’s because you’ve desensitized the stretch reflex of the hamstrings.

This is usually not a big deal, but when you are doing it to push the extremes of your physiology and then pitch on it, it becomes more significant. Pitching already puts a ridiculous amount of stress on your arm.

Weighted Balls Cause Chronic Cumulative Damage to the Musculoskeletal System

Luckily, I think the primary reason why we are seeing the change in external rotation is from the acute desensitization of the proprioceptors we just discussed.

However, it would be short sighted to also not consider some chronic damage, especially if pitching with this increased external rotation.

During the pitch, the arm rapidly transitions from external rotation to internal rotation to start accelerating the ball. This places tremendouse stress of the static and dynamic stabilizers of the shoulder.

baseball pitching biomechanics - max external rotation layback

Statically, this can damage the anterior capsule of the shoulder. You don’t want this.

Dynamically, we are seeing damage to the muscles that need to eccentrically slow down the layback and transition to arm acceleration. These muscles include the latissiumus dorsi, teres major, pectoralis, and subscapularis muscles.

Have you noticed how common lat strains are in baseball now? We rarely saw this 10-20 years ago.

The acute changes are likely also leading to chronic cumulative changes.

So What Does All this Mean?

So now that you know way more than you probably ever wanted to know about shoulder external rotation, let me explain why this matters.

Quite simple, we know that the more external rotation you have the more velocity you have. We also know this increases the stress on your shoulder and elbow.

This is the part that sounds like rocket science, but is actually common sense. It’s physics. More layback allows the arm to throw harder, which puts more stress on the arm.

baseball pitching layback external rotation
Image from Wikipedia

Duh, right? Makes sense now, right?

Most of the proposed theories on why weighted balls helped increase pitching velocity are likely not true. The gain in layback is the primary reason, no doubt in my mind.

Weight ball programs do not increase arm speed, do not increase arm strength (in fact we showed they inhibit strength development), and do not do any of the other things that have been proposed. We have now officially studied this all and concluded this with our research.

Weighted balls increase layback, which increases velocity, which both increase stress, which all increase injury rates.

Again, makes perfect sense now, right?

Do We Even Need Weighted Ball Training Programs?

OK, I get it, you still want to use weighted balls. They seem magical on the internet.

I’m completely fine with that. I use them myself with many of the players we work with, however not all of them.

As we continue to learn more, I think we realize that weighted balls have a very small place in our velocity development programs for the right person at the right time.

They should not be performed blindly on a big group of people, like we are seeing being implemented for youth, high school, and college teams across the country.

This is silly.

As with everything else in life, it’s all about the dosage. Ever hear the phrase “there’s too much of a good thing?”

We are really overdosing on weighted balls.

But I’m going to end this article with a question… do we even need weighted ball training programs?

I’m not talking about substituting weighted ball training with many of the things that have been proven to enhance velocity without causing injuries, like strength training, power development, arm care, and proper biomechanics. I’m talking about do we need to be doing these elaborate weighted ball training programs all offseason.

Based on this current study, if layback range of motion increases so much so quickly, and more layback means more velocity than maybe all we need is a quick and simple warm up with a weighted ball.

This could give a small stimulus to desensitive your propioceptors enough to allow a little more layback and a little more velocity, without having the put the body through weeks of a weight ball training program.

This sounds a lot safer on the body to me.

This also sounds like our next study that is in the works. Stay tuned… :)

The Effect of a 6-Week Weighted Ball Training Program on Baseball Pitchers

Sports health cover pageI’m very proud to say that our first research project on the effect of baseball pitchers training with weighted balls has finally been published!  Big thanks for my coauthors Lenny Macrina, Dr. Glenn Fleisig, Kyle Aune, and Dr. James Andrews.

By now, many people have seen the results of the study.  I’ve presented the data at APTA, ASMI, PBATS, Sabermetrics Seminar, and many more as we went through the publication process.  We felt this study was very important for the game of baseball as we have seen such a large growth of interest in weighted ball programs, without a complete understand of what happens to the body.

I believe we have found the mechanism behind why throwing weighted balls enhances velocity.  It’s not a change in biomechanics, arm speed, or strength.  It’s a gain in layback.  This likely also explains why these programs are more stressful and show higher injury rates.  I’ve written a summary below, but I urge you to read the full study for all the details:

The Effect of a 6-Week Weighted Ball Training Program on Baseball Pitchers

The Effect of Weighted Ball Training on Baseball Pitchers

We performed a 6-week weighted ball training program with high school baseball pitchers.

Players gradually ramped up over the 6-weeks to include kneeling, rocker, and run-and-gun throws with balls ranging from 2oz to 32 oz.  All participants had been throwing and weight training prior to prepare for the program.  We modeled this off very commonly performed programs.  We feel that this program, if anything, is more conservative than many of the programs we have seen.  Many other programs are longer, have less of a ramp up, and include balls that are even heavier.  Also realize that throwing a heavier ball with less intensity over a longer period of time is likely more stressful on the body, it’s just physics.

The max weight, 32oz, was used for a total of 18 full effort run and gun throws.  This represents only 3% of the total balls thrown over a 6-week period.

A control group was used that did not perform the weighted ball program.

After 6 weeks, the weighted ball group did increase velocity by 3.3%.  It should be noted, though, that 8% showed no change, and 12% showed a decrease in pitch velocity. Furthermore, 67% of the control group also showed an increase in pitch velocity.

Arm speed and arm strength did not increase, and biomechanics did not change, meaning the gain in velocity was not from any of these commonly theorized reasons.  In fact, arm strength was up in the control group, suggesting that a weighted ball program may actually inhibit strength gains.

The weighted ball group showed almost a 5 degree increase in shoulder external rotation, or layback.  This has been correlated in previous studies to both velocity and stress on the arm.

The weighted ball group had a 24% injury rate.  Half of these did not occur during the study, they occurred the next season, which is an important finding.  There were no injuries in the control group.

The Road to Publication

Many people don’t know what happens in the background when conducting studies with sound methodology and peer review with a prestigious journal.  So I thought I’d share that process.

It takes weeks to months to go through a credible IRB to assure the project is designed well.  It then takes months to conduct the trials to actually acquire the data.  This has to be planned well to assure consistency and valid data.  It takes weeks to analyze the data, going back and forth with the statisticians to sort through the results to pull out the clinical implications.  It then takes months to write the manuscript, remember we are clinical researchers, mean we actually work with clients in the day!  We write these in our spare time at night and on weekends.  The manuscript is then submitted to a journal, which takes months to get back to you, they likely have hundreds on manuscripts submitted per month.  You then work with 3 peer reviewers that take a hard look and criticize the paper.  Their goal is to assure the results are reliable, valid, and without bias.  You then go back a forth a few times over several months.  At this point in time >90% of articles have been rejected, so if you’ve made it this far, congrats!  The editor now takes over and we have another back and forth to assure the results are clear and everything is in order.  The publisher then reaches out with page proofs for you to approve.  Then, magically one day, you get an email with a PDF attached and a link to the publication!

Exhausted just reading that?  Yup, me too.

It’s a LOT easier to just type away and hit publish on a blog, but so many questions are unanswered when that happens.  Was the study designed properly?  Did the procedure follow sound methodology to assure the results are valid?  Were the methods reliable?  Was there no bias from the authors?

That’s why we felt it was so important to get this data out to the scientific community in a medical journal.  Doctors, physical therapists, athletic trainers, and strength coaches need to understand the effects of weighted balls when designed injury prevent, performance enhancement, and rehabilitation programs.

Should You Use Weighted Balls?

Weighted balls are not evil.  They are not the cause of injuries.

Throwing itself is the cause.  Weighted balls just change the stress to the body.

They can be used strategically if you understand this and build a program that takes the science into account.  However, remember there’s more than velocity when it comes to pitching.  And science also tells us that there are MANY other ways to enhance velocity that are much less stressful.

Weighted balls are just another tool for us to be used with the right person, at the right time.  But that is probably less often than you think.  If you are a coach using these programs, you must understand this.  There are so many teams now just starting a generic templated program for all players.  There is a better way.

The Future of Weighted Ball Research

This study was phase one.  We wanted to look at the results of a 6-week program that is commonly performed in high school players.  This study has shown us a few very important things and has brought to attention what I believe is the primary reasons weighted balls increase velocity (and injury risk).

We have already finished phase two and phase three.  Phase two will look at the effect of different positions and ball weights on the arm, mechanics and velocity.  This study will help us understand which positions and balls to use.  Phase three will look at the immediate effect of different ball weights on the arm.

Together these three studies will shed a lot of needed light on the use of weighted balls.

Once these papers are finalized, the important part starts.  We’ll then work on a clinical commentary paper that summarizes all of our past studies and the science of weight balls.  This will be extremely valuable, and an import resource for baseball coaches, parents, and players to read.

There are still many questions to be asked.  It’s almost impossible to answer them all, but we are lot closer to understand the true science behind baseball pitchers training with weighted balls.

Help Spread the Word

Want to help?  I hope so.  Trust me, we are very busy at Champion PT and Performance with baseball injuries.  But nothing would please me more than reducing injuries and helping baseball players take it to the next level.  How’s that for sincerity.

This info needs to get to the baseball coaches, players, and parents.  Please share and spread the word.  Thank you!

Understanding Tommy John Surgery and How to Avoid It

Note from Mike: Today’s post is an excellent article from New York Yankees team physician, Dr. Chris Ahmad, and Frank Alexander, ATC.  We know that Tommy John injuries continue to rise. Chris and Frank have written a new book to help educate your baseball players, parents, and coaches about Tommy John injuries, and more importantly, how to avoid them.

We have an epidemic on our hands in youth baseball.  With nearly half a million participants, baseball is one of the most popular high school sports in the United States.1 Injuries to the throwing arm continue to grow every year and there is no slowing down in sight.

While there are a number of injuries that a baseball player can succumb to, the most well-known are Tommy John injuries, also known as ulnar collateral ligament (UCL) tears. Once considered a career ending injury, Dr. Frank Jobe revolutionized baseball and all of sports medicine in 1974. That summer, he performed the first UCL reconstruction on the most famous recipient – and namesake – of the surgery, Tommy John.  

UCL injuries are the most studied condition in all of orthopedic surgery and its popularity in the media has made it a preeminent sports injury.

It is estimated that 1 in 4 Major League pitchers will need Tommy John Surgery in their career. In 2000, 13 MLB pitchers had UCL reconstructions. Over a decade later, in 2012, that number had increased nearly three-fold to 32 pitchers requiring the season ending surgery.2

Unfortunately, the increasing numbers of players falling victim to UCL injuries translate to the younger levels of baseball as well.

Evidence suggests the trend has impacted adolescent athletes with a 50% increase in UCL reconstructions in high school baseball players aged 15 to 19 years old.3 In New York State alone, the volume of UCL reconstructions increased by 193% over a 10-year period.3  These younger players may feel pressures within the competitive culture in youth baseball. This may lead players to play through pain and more talented players may be told they have to throw more frequently and with greater intensity.

While there are several reasons why there are so many Tommy John injuries, research has described overuse to be the main cause of player injury.

There is a 500% increase in risk for surgery for those players that pitch more than 8 months per year and a 400% increase in risk is observed for those that throw more than 80 pitches per game.3

Not only are younger athletes enduring this big-league problem, their understanding of the injury leads many of them to want the surgery even in the absence of injury.  There are still many myths about Tommy John Surgery.

Many players see their idols in Major League Baseball have surgery and return to the field throwing harder. What the younger athletes don’t see is the painstakingly long hours that the pros put into their rehab. Mike Reinold recently had a podcast episode with several Tommy John patients to describe their experiences.

There is a common belief among players, parents, and coaches that the rehab program post-Tommy John was shorter than 1 year and allowed for a quick return to throwing.4 We are now seeing players at the higher levels of competition returning to sport around 14-16 months and the average at the Major League level is 15 months post-operatively.

The popularity of Tommy John Surgery in addition to the perceived glamor players receive upon their return is what leads the younger players to think surgery is necessary. Research from our office has shown that 51% of high school baseball players believe that they need Tommy John surgery in order to enhance their performance.4  This is in the absence of an injury – meaning, players that are healthy think they need surgery just to get better at the game of baseball.

Players should have surgery for UCL insufficiency (i.e. tear), not to improve their performance. While we want to celebrate the return of our favorite athletes to the playing field, we only hear about the successes and not much about the players that are unable to make it back. The success rates of Tommy John Surgery range between 80 – 90% and even though players make it back to the field, pitchers throw fewer innings post-operatively.2,4 Having surgery places an enormous burden on the player mentally, physically and emotionally.

As the numbers of youth athletics participants continues to rise, it may seem that elbow injuries have become a part of America’s pastime.  Leaders in the field have established guidelines for our younger players in hopes that they will remain injury free and continue a long, healthy career.


A Guide for Young Baseball Players

Even with the implementation of these guidelines we continue to see a rise in throwing arm injuries leading us to write our book Understanding Tommy John Surgery and How to avoid it: A Guide for Young Baseball Players.


Understanding Tommy John Surgery and How to Avoid It


Our vision for Understanding Tommy John Surgery is to help younger players better understand elbow injuries and that it is not okay to play through pain. Some warning signs may include decreased velocity, elbow tightness, and difficulty warming up.  We also discuss a number of different ways for youth baseball players to stay healthy such as keeping a log of the number of innings or pitches thrown, proper warm-ups, and sport diversification.

By allowing our players to understand their elbow and know that playing through pain is not a good idea, we may finally see a reverse in the trend of Little Leaguers being diagnosed with Big League problems.

If you’d like to learn more and join in our efforts you can visit Dr. Ahmad’s website and get your own copy of Understanding Tommy John Surgery and How to avoid it. If you or a family member has a baseball related elbow injury, Dr. Ahmad will happily review the images with you as a free service and is available to all baseball players across the nation. You can learn more at his website!




  1. Saper, MG, Pierpoint, LA, Liu, W., et al. (2018). Epidemiology of shoulder and elbow injuries among United States high school players. American Journal of Sports Medicine, 46(1), 37-43.
  2. Erickson, BJ (2015) The epidemic of Tommy John Surgery: the role of the orthopedic surgeon. American Journal of Orthopedics, 44(1), E36-E37.
  3. Hodgins, JL, Vitale, M, Arons, RR, & Ahmad, CS. (2016). Epidemiology of medial ulnar collateral ligament reconstruction A 10-year study in New York State. American Journal of Sports Medicine, 44(3), 729-734.
  4. Ahmad, CS, Grantham, WJ & Griewe, RM (2012) Public perceptions of Tommy John Surgery, The Physician and Sportsmedicine, 40(2), 64-72.

The Science of Weighted Baseball Training Programs

Weighted baseball training programs to enhance pitching velocity are becoming more popular each year.  However, there are so many questions regarding the proper use of  weighted baseballs:

  • Are weighted baseball training programs effective at improving pitching velocity?
  • If so, why do weighted baseball velocity programs work?
  • Does everyone gain velocity with weighted ball programs?
  • Are weighted baseball programs safe for everyone to perform?
  • Do we know the long term implications of these programs?

We still do not know many of these answers.  There are a bunch of great facilities around the country that are pushing the limits with not only training with weighted baseballs, but also attempting to collecting data to help answer some of these questions.

We are getting better everyday, but there is still a great need for more information.  Like anything else, the pendulum is swinging towards the side of pushing the limits.  I’ve discussed this in a past article on baseball velocity programs and essentially noted that I felt we have not found out the most appropriate dose, and are simply are overdosing.  We need to fully understand the science of these programs before we let this swing too far.


The Science of Weighted Baseball Training Programs

We have just recently finished a 2-year study looking at the safety and effectiveness of weighted baseball training programs at Champion.  Lenny Macrina and I conducted the study in collaboration with ASMI, Dr. Glenn Fleisig, and Dr. James Andrews.

This is the first real research study looking at the way a 6-week weighted baseball training program effects pitching velocity, arm stress, range of motion, strength, and most importantly, injury rates.

The results are eye-opening for sure.

As many of you know, planning, conducting, and publishing a real research project takes time, often years from the beginning to the eventual publication.  It must go through a strict review to assure safe methodology and a lengthy peer-review process to assure there is no methodological flaws or bias that may be skewing the data.

It’s great that many people around the internet are discussing the data that they collect at their facilities.  This is a great first step in becoming better as a group of professionals.  but without careful scrutiny of their research design, methodology, statistical analysis, and results, it’s tough to call that data “research.”  There are so many variables that could skew the data, it’s hard to draw accurate conclusions.

Our project has been presented at numerous scientific meetings and is currently submitted for publication.  It’s actually been nominated for the Sports Physical Therapy Excellence in Research Award.

Are Weighted Baseball Velocity Programs Safe and Effective?But because it takes so long to get to publication, I wanted to write a summary of our findings.  I recently published this on, an amazing website I have started dedicated to providing trust worthy information to advance the game of baseball.

Click below to read my summary of our research project on EBP, and please be sure to share this with any baseball player, parent, coach, rehab, or fitness specialist that may work with baseball players:



How to Assess for a Tight Posterior Capsule of the Shoulder

Over the years, the idea of posterior capsular tightness and glenohumeral internal rotation deficit (GIRD) in baseball pitchers has grown in popularity despite not much evidence.

I routinely see baseball players ranging from kids to MLB pitchers that have been told they have GIRD and need to aggressively stretch their posterior capsule and into shoulder internal rotation.  One of the first recommendations I make is essentially addition by subtraction – stop focusing on these areas!  I’ve discussed at length my feelings on why I don’t use the sleeper stretch, which is something I haven’t used in over a decade and none of my athletes have a loss of internal rotation.

Many people assume that GIRD is caused my posterior capsular tightness, without assessing the posterior capsule itself.  Blindly applying treatments without completely assessing the person is always a bad idea, especially considering GIRD may be normal and not even an issue.

Assessing the posterior capsule can be tricky and most text books continue to demonstrate the technique poorly.  I wanted to share a quick video showing how to assess the posterior capsule of the shoulder.

Perform your assessment of the posterior capsule this way and you’ll realize most people can actually sublux posteriorly and that mobilizing the posterior capsule isn’t what they need for GIRD!  Keep in mind this is applicable for athletes, you can certainly get a tight posterior capsule for many reasons, I just don’t think this is the primary cause of GIRD so shouldn’t be the primary treatment.

Learn Exactly How I Evaluate and Treat the Shoulder

If you are interested in mastering your understanding of the shoulder, I have my acclaiming online program teaching you exactly how I evaluate and treat the shoulder!

shoulder seminarThe online program at takes you through an 8-week program with new content added every week.  You can learn at your own pace in the comfort of your own home.  You’ll learn exactly how I approach:

  • The evaluation of the shoulder
  • Selecting exercises for the shoulder
  • Manual resistance and dynamic stabilization drills for the shoulder
  • Nonoperative and postoperative rehabilitation
  • Rotator cuff injuries
  • Shoulder instability
  • SLAP lesions
  • The stiff shoulder
  • Manual therapy for the shoulder

The program offers 21 CEU hours for the NATA and APTA of MA and 20 CEU hours through the NSCA.

Click below to learn more:


3 Ways to Improve Throwing Velocity by Enhancing Lower Body Force Production

Pitching a baseball takes a tremendous amount of skill to throw with velocity and accuracy.  Improving velocity tends to be the primary concern of many pitchers, especially youth baseball players.  In order to learn how to enhance velocity, it’s more important to study scientific evidence than to rely on anecdotal information and traditional baseball concepts.

pitching velocityA recent study was published in the Journal of Sports Science and Medicine by a group of researchers in Japan that compared how youth and college pitchers use their trunks and legs during their pitching mechanics.

They found that youth and college pitchers threw with similar biomechanical kinematics, meaning that their mechanics were similar.

However, what they did find was that momentum and force generation were higher in the college pitchers.  College pitchers exhibited:

  • Greater push off on the pivot leg during stride
  • Greater pelvis and trunk rotation throughout the pitching sequence
  • Greater stride leg control during acceleration
  • Greater stride leg extension explosive force approaching ball release

It should be noted that the data was normalized to body mass to take into consideration the lower weight and size of adolescent pitchers.  This make the comparison fair.

These results correspond well to a previous report by the same authors that showed college pitchers with higher velocity also showed greater ability to produce force in their legs and trunk in comparison to college pitchers with low velocity.

In addition, the results were also similar to what Glenn Fleisig, Dr. James Andrews, and ASMI showed in regard to the upper body and trunk when comparing youth and older pitchers.


To Maximize Velocity, Generate More Force with the Legs and Trunk

Again, mechanics of youth are similar, but their ability generate force is different.  Generating more force with your legs and trunk results in greater velocity.

But getting stronger probably isn’t enough.

Based on these two studies it is apparent that getting stronger isn’t the only thing needed to increase your pitching velocity.  You also need to be able to generate more speed and power.

Part of this is simply getting older and bigger.  A stronger body and a longer arm generates more force, that’s just simple physics.  But there are also some tweaks you can perform to generate more force.  Here are three things youth baseball pitchers can train to improve their pitching velocity based on this new scientific evidence


Improve Strength

Leg and Trunk Power VelocityWhile strength probably isn’t enough alone, strength is probably the first factor youth should focus on to improve velocity.  To develop more power, you need to be stronger.  The more force you can exert, the harder you will throw.

Based on these studies, lower body strengthening is an area that deserves a lot of attention.  The legs are used during the early phases of pitching, so the amount of force produced early in the delivery will result in more force being developed and transferred through the body for the rest of the pitching sequence.

Take a look at professional baseball pitchers.  The majority that look like they throw effortlessly have big legs, hips, and butts.  Jon Lester is a great current example, and Roger Clemens is probably a great former example.

The shorter and smaller framed pitchers tend throw with much more effort.

The bigger and stronger your legs, the more force you can generate, which has been shown in numerous studies to correlate to velocity.


Enhance Speed

medicine ball pitching velocityI think a lot of youth baseball players stop at strength, and that can actually be detrimental.  Research in the strength and conditioning world has shown that training certain qualities, like strength and speed, results in adaptations of the body.

Better stated – train slow and you’ll throw slow. [Click to Tweet This]

Once a baseline of strength is established, I tend to focus on “intent.”  What I mean by that is you want to develop the athlete’s ability to explode.  This is an area that many youth do not understand.  They don’t know how to explode.

Once a young athlete understands how to move a heavy weight slowly, you want them to transition this to moving a moderate weight faster, and eventually a lighter weight even faster.

Exercises like plyometric jumps, medicine ball throws, kettlebell swings, and speed trap bar deadlifts are all very effective in this spectrum of training.

On the baseball training side of the equation, this is where long toss and overweight/underweight balls become important for pitchers (there is a right way and wrong way to implement these).  I’m not sure any of these develop “arm strength” as much as they develop “arm speed.”

Big difference.


Maximize Stability

youth baseball velocityLastly, and probably the least well understood and implemented, is training for stability.  To improve throwing velocity, you need the proper motor control and dynamic stability to stabilize both the arm and the stride leg.  People to tend to understand the arm more these days, but I wouldn’t ignore the stride leg.

To properly transfer force that is developed from your pivot leg, you need a strong AND stable stride leg.

You need stride leg stability for force transfer, but don’t forget the body has internal regulations to avoid injury.  If the stride leg can’t stabilize the force, theoretically you body won’t allow you to develop the force.

This also goes for the arm, and I believe why using weighted balls the WRONG way can be harmful, especially for youth pitchers.  Your arm needs to be able to withstand the force to produce the force.  Otherwise, your brain is smart enough to regulate force development.

To maximize velocity, you need to train the body to develop and withstand force.  Too many of us only focus on developing force alone.  This can result in ineffectiveness of training programs as well as injury by pushing past your physiological limits.


Understand that maximum velocity in a baseball pitcher occurs through a combination of many qualities.  Work on enhancing each of these will result in a maximum amount of velocity while reducing the chance of injury.


Free Presentation on Maximizing Performance and Reducing Injuries in Baseball Pitchers

To learn more about how I enhance performance in baseball players while reducing the chance of injury, enter your email below and I’ll send you access to my FREE 45-minute presentation where I discuss why injuries occur in baseball players and the 5 principles that I follow to build my programs to safely enhance performance while reducing injuries.

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4 Keys to Staying Healthy During the Baseball Season

The latest Inner Circle webinar recording on my 4 Keys to Staying Healthy During the Baseball Season is now available.

4 Keys to Staying Healthy During the Baseball Season

4 Keys to Staying Healthy During Baseball SeasonThis month’s Inner Circle webinar is on 4 Keys to Staying Healthy During the Baseball Season.  In this webinar I’ll discuss:

  • How and why injuries happen in baseball
  • What you should watch out for in regard to loss of mobility
  • My criteria you should achieve before picking up a ball everyday
  • The #1 thing I see youth players do wrong that causes injuries
  • How to maximize performance by minimizing overuse

To access this webinar:

Enhance Performance During the Baseball Season by Reducing Overuse

I’ve talked over and over again that overuse is the number one reason why we have so many high school and youth baseball injuries.  It’s likely the most significant factor while also being the easiest to address.  People grasp the concept that overuse can lead to injury, but overuse is also the number one reason why performance is decreased over the course of a baseball season.

But it’s all about temptation, right?  Let’s use a different example.  Eating that donut right now probably isn’t going to kill me today (I guess I could choke on it…), but creating a bad habit, like eating a lot of donuts, will have an impact on my longevity and quality of life.  My short term actions will decrease my long term results.

Taking it back to summer baseball, it’s tempting to play in multiple leagues or to sign up for every showcase and tournament you can find.  You want to get the most exposure that you can, right?  Realize that your short term actions will decrease your long term results.


Understanding the Stress of a Baseball Season

I like to think that you start every baseball season at 100% capacity, and slowly drip down over the course of the season.  This is normal.  There is this magical line of injury, let’s say at 80% capacity.  You can play at 81% but you can’t play at 79%.  This is a concept I have developed over the years because I see this ALL the time. I’m not sure why, but I do feel there is this magical line.

Here is what that magical line looks like.  The blue line is your magical line that I don’t want you to dip below over the course of the season.  The red line is your capacity.

Youth baseball overuse


Once you dip below that magical line of 80%, it’s really hard to get back up.  You end up struggling to stay above water all season.  You play on the weekend, empty the tank, and then we struggle to get you back over the line all week.  This is by far the worst way to get through a season.

baseball overuse

Some people spend every season like this and I wonder if they ever truly reach their potential. People that I tend to see that do wiggle back and forth over this line tend to be doing 1 of 2 things:

  1. Way too much in general
  2. Trying to make big gains during the season

What I mean by the second point is that you spent all winter working hard to get stronger, improve your mechanics, and enhance your velocity.  But, you continue to push your physiological limits with your training in season when you should be scaling back the training and scaling up the skill competition.  This leads to overuse, even though your actual innings may be down.

I’d rather you be at 100% capacity at 80% of showcases, rather than at 80% capacity at 100% of showcases.  Plus, 80% of you isn’t going to impress a scout or coach.  The higher your red line, the higher your performance.


Enhance Performance During the Baseball Season by Reducing Overuse

My job is to slow down that drip.  I want to make the red line slowly drip over the course of the season.

baseball inseason injury

I do this by helping you maintain your mobility, strength, stability, and endurance.  Notice I said “maintain” and not “gain.”  You can also help slow this drip down with proper inseason programs.  Paying attention to your recovery, sleep, and nutrition also play a part.

Your job is to raise your capacity as much as possible.  You want to make that blue line go down as much as possible.

baseball performance


How do you do this?  It’s building your base in the offseason through a comprehensive performance training program that focuses on strength, power, speed, agility, endurance, mobility, and arm care.  If it’s midseason for you and you are struggling, keep this in mind next offseason!

I work with a lot of young athletes during the season.  It is VERY obvious to me inseason which player put the effort in during the offseason to prepare.  Their durability is noticeably improved.Overuse is specific to each individual.  You can slow down your drip and raise your capacity with the right programs.  This is why your innings may be far less than someone else on your team but you are always hurt and they stay injury free.


Learn More About How I Manage Baseball Players Inseason

If you want to learn more about how I manage players during the baseball season, this month’s Inner Circle webinar will discuss my 4 keys to staying health during the baseball season.  The webinar is Thursday June 25th at 8:00 PM EST, but will be recorded for Inner Circle members.