Definition of Baseball Biomechanics


What is the Definition of Baseball Biomechanics?

As a clinician working with baseball players for over 30 years, I am often asked what is the definition of baseball biomechanics?  In other words, give me the biomechanical definition of throwing in baseball.  The quick answer to this question is baseball biomechanics is the quantitative study of how your body moves with throwing or hitting the baseball.

Why would we want to look at a baseball players biomechanics?  There could be several reasons why this would be helpful.

Why Study Biomechanics in Throwing the Baseball?Definition of baseball biomechanics from the Jacksonville Orthopaedic InstituteDefinition of Baseball Biomechanics

1) To improve their performance or their ability to play baseball.  In youth baseball, coaches teach young athletes the correct way to throw a baseball.  I remember my dad telling me that you must put your thumb down and up when you break your hands out of the glove to throw.

Definition of baseball biomechanics from the Jacksonville Orthopaedic InstituteBaseball Biomechanics and Learning How To Throw a Baseball

2) To prevent an injury from occurring would be another good reason.  In my years of watching baseball, if I saw a pitcher who "wrapped" his hand when pitching, I could predict a medical elbow injury in his future.  Now, did I randomly go around telling kids to change their mechanics?  No, is the answer to this question.  If they asked me to look at their mechanics, I would certainly point this problem out to them.  Through the years, I only changed a pitchers mechanics when they had pain or performance issues.  The older the player gets, the harder it is to change their biomechanics.

3) The final reason to change a baseball players biomechanics is that the were already injured.  This is the areas that I have changed almost 100% of a baseball players biomechanics.  It has been my experience that the best outcomes occur with baseball throwers after an injury when they return to the proper biomechanics.  Sometimes, parents or coaches refused to listen to my advise with changing their mechanics.  They recovered from their injury, they wanted to go back and play tomorrow.  Thanks for the advise but we need to play tomorrow.  I knew they would be back soon with a re-injury and they were.

What is the best way to look at a baseball players biomechanics? 

If you are new to looking at the biomechanics of throwing, you must start with slowing everything down with a video.  When you are more experienced, you can just watch a kid throw and pick up things right away.  The speed of the arm and the body in throwing a baseball is really fast.  Professional baseball pitchers deliver the ball to the plate usually under 1.3 seconds.  Therefore, a video of this process can really help you look at what's going on.  At JOI Rehab, we use the Dartfish Video Program to slow down the video and we can highlight items on the video.  

Biomechanical Analysis

Definition of baseball biomechanics from the Jacksonville Orthopaedic InstituteBiomechanics Analysis in Baseball Pitchers

Using a program like Dartfish allows you to go into the slow motion frame by frame to see areas which need improvement.  To improve performance, we then look at ways to obtain optimal muscle recruitment.  In pitching, usually this is to get the athlete to use their core or abdominal muscles.  It could also be to improve their amount of functional external rotation of their arm.  Dartfish allows you to also measure certain aspects of the body.  These key measurement of angles are important to see what is going on and can prevent an injury from happing.  Here are some examples:

Lack of External Rotation of the Shoulder

1) The amount of external rotation during the cocking phase of throwing.  If the athlete doesn't have enough ER, they can be prone to injury or they may not produce enough force to throw the ball.  This can be fixed by putting the athlete on a stretching program for ER and pect flexibility.  So many high school athletes work the front of the shoulder in the weight room.  This leaves the muscles in the back of their arm with a weakness.  The muscles of in the back of the arm are important for throwers.  The muscles stop the arm after you throw the ball.  Most injuries occur in this stopping of the throwing motion.

JOI Rehab Shows an External Rotation stretch for baseball playersStanding External Rotation Stretch for Baseball


Decreased Trunk Flexion or Follow Through

2) I like to measure the amount of trunk flexion.  In other words, the amount of bend in their back after throwing the ball.  This is important to see if they are following threw after pitching.  With performance, a pitcher who doesn't follow through will leave the ball up in the zone.  The follow through is also important to decelerate the body after throwing the ball.  If you use the entire body after throwing, it is better than just the arm.  It will spread the force of stopping the throw out to several body parts instead of just the arm.  Remember, most injuries occur after throwing the ball. 

What Are The Most Common Errors When Throwing a Baseball? 

As a Certified Athletic Trainer, I have seen over 1,500 high school baseball games in my career.  Now, that's a lot of baseball.  Each year, I say to myself that I have seen it all.  Each year I am proven wrong and see something strange with a pitcher.  The best way to look at a pitcher's biomechanics is to think of it like a puzzle.  To finish the puzzle correctly, you have to look at each and every piece and they have to fit!

In baseball, the pieces of the puzzle must all fit together to have the highest level of performance and to decrease the risk of injury.

Definition of baseball biomechanics from the Jacksonville Orthopaedic InstituteDefinition of Baseball Biomechanics

 3 Most Common Throwing Errors in Baseball.

In my experience, here are the 3 most common errors when throwing a baseball.

1) The first error that I see the most often is the lack of following through after the pitch.  The easiest way to fix this error is first to make the athlete aware of this error.  You can work with them to bend over and touch the dirt after the throw.  Filming them so that they can see the problem really helps.  This can be complicated as well with their stride length and falling off the mound to the left or right.  It is the most common error, but it is also the easiest to fix.

2) The second error that I see is the "Wrapping" of the arm.  This wrapping is not like gift wrap!  This problem in my experience is the hardest aspect to fix in throwers.  Wrapping the arm is when the pitcher does not perform the thumb down and up when breaking his hand from the glove.  They do a version of thumb down and wrap it behind their back.  This change puts an extreme amount of pressure on the inside aspect of the elbow.  All of those athlete's with Little Leaguer's Elbow and having Tommy John Surgery fall into this area.  To fix this error there needs to be a lot of muscle memory repetitions to return to the proper way to throw.  Throwing with a towel in the mirror so that the thrower can regain their muscle memory is where I start.  These pitchers take some time to rehab. 

Definition of baseball biomechanics from the Jacksonville Orthopaedic InstituteBaseball Biomechanics Wrapping of the Arm

3) The final error in my top 3 is not being balanced in the throwing motion. This error has a cascade effect to other errors in throwing.  So many pitcher's rush their throwing motion in the attempt to throw harder.  The speed of the throwing motion does not make you throw harder.  I firmly believe that how hard a pitcher throws comes from a strong core, rotator cuff strength & endurance and from trunk rotation.  All of these things are optimized by being balanced right before you throw the ball.  Being balanced once you lift your leg will allow all of the force that you produce to be generated directly towards the plate.  My dad told me that this part in the motion is like the coiling of a spring.

In conclusion, I hope I have been able to help explain some of the aspects of the biomechanics of baseball throwers.  I should be very clear, I don't randomly go out and change pitchers mechanics at the high school level.  My experience is to only change an athlete's biomechanics because of an injury or related to poor performance.  It is rare to find a baseball pitcher with perfect biomechanics.  Each and every athlete is built differently and can have different aspects of throwing that works for them. 

To schedule an appointment with a JOI Orthopaedic Surgeon who treats baseball throwers, please call 904-JOI-2000 or schedule online.  To schedule an appointment with the JOI Sports Center for baseball athletes, please call 904-858-7045. 

By: Tim Wall MS/Certified Athletic Trainer






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