What Causes Throwing Arm Injuries?

What Causes Throwing Arm Injuries?

By: Ernie Smith

At the MLB level the thoughts behind why pitchers get injured have changed over the years.  In the 1980’s it was thought that the splitter was a culprit.  In the 1990’s this changed to the curve ball.  In the late 1990’s mechanics came under scrutiny.  While these things may all be contributors, on a logical level we recognize that age, size, strength, mobility, and training techniques also are part of the equation.  The one thing we know correlates directly with injury is overuse.  Injured players pitch more months, games, and pitches per year.  They pitch more innings, pitches, and warm-ups per game. 

Related studies:

  • Olsen AJSM ’06
  • Fleisig AJSM ‘11
  • Register-Mahlick – Athl Train ‘12

We need to understand that overuse is not just a data point of “innings pitched” or “pitches thrown in a game”.  And here is where the sport and the organizations that govern it have failed us to some degree even though they are doing their best to be helpful.  With injuries on the rise there has been a rush to put total pitch count limits in place and to do so by age.  What this approach fails to recognize is that overuse is an equation of quantity and intensity.  A couple of examples come to mind:

  • Would you suggest that an MLB pitcher who throws 100 knuckle balls puts the same stress on his arm as a guy that throws 100 pitches and “sits” at 98mph on his fastball?
  • Would you agree that a pitcher who throws 15-pitches each inning for two innings (total of 30 pitches) has the same stress on his arm as a pitcher who throws 30-pitches in a single inning?

The answer to both questions is obviously “no”.  But the disservice doesn’t end there.  If a player warms up by throwing some of his bullets at full intensity before he goes into the game, shouldn’t those pitches count against his daily limit as well?  In my mind they should.  If a player’s ramp up is exceptionally steep because he’s going in relief for a guy who is getting hammered, and there just isn’t much time to get ready, is that a higher intensity outing?  My opinion is that such an outing is much higher intensity, due to the steepness of the ramp-up, and puts that player at significantly more risk of injury.

One thing we excel at is providing players and coaches with advice on how to manage quantity and intensity of throwing more effectively.  This includes warm up planning for different scenarios plus managing work load in games and throughout a season.

Ernie Smith, Founder and CEO, Illinois Baseball Edge, Ltd.

Ernie Smith

Ernie Smith, aka “Smitty”, founded the Illinois Baseball Edge, Ltd. in 2021. His coaching career began long before that in the summer of 1980, and continues to evolve today with over 110 seasons of experience (if one counts Spring, Summer, and Fall separately). His focus upon long term player development and performance enhancement, with measurable results, is an approach not often found in baseball or softball and has led to some significant milestones. In recent years that approach has blended well with the evolution of player centric training methods including hyper personalization.
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