How to Prevent Youth Pitcher Arm Injuries

I researched and collated much information on pitcher arm care into a parent advice guide for my spring PONY team in April 2014. Here I present the same information, expanded and reworked into a more blog-appropriate format, and updated gradually over time as I learn more.

In February 2015 I attended a workshop on sports medicine presented by several physical therapists and doctors from the Sports Medicine Center, UCSF Benioff Children’s Hospital (Oakland). I learned additional details and one major new concept (core strength) which I incorporated into this post.

The pitching arm problem

It is common for kids who pitch too much at a young age to injure their throwing arms. I have already encountered several ball players who have had injuries, including a 13-year old neighbor who was not able to throw for over a year. I hear that many good pitchers in our area get sore arms frequently by the time they are 11. Even a few of my son’s 9-year old summer all-star teammates are beginning to experience arm soreness after pitching.

Many articles have appeared lately discussing youth baseball arm injuries and the rapid increase in Tommy John surgeries. There is also the occasional passionate appeal by a strength and conditioning specialist.

The main point of most of these articles is that many kids are pitching too much, and there is research to back that up. Pitching injuries usually do not occur until many thousands of pitches have been thrown. But most kids who throw thousands of pitches do not get injured, so obviously throwing too many pitches is not the only issue.

I believe there are five main contributing factors that lead to arm trouble. In this guide I will briefly discuss these five factors, and then detail what coaches, players, and parents can do to keep arms healthy. If you assimilate these five factors as principles, then you will find the detailed advice that follows to be logical and easy to remember.

Five factors contribute to pitcher arm troubles:

  • Pitching when arm is not warm enough
  • Pitching when arm is sore or hurting
  • Pitching too much
  • Insufficient “core” strength
  • Pitching with poor mechanics or overthrowing

Warming up consists of getting the body warm in general (running, jumping jacks, etc.) and more importantly warming up the muscles involved in pitching with dynamic stretches and gentle throwing. On cool days, it’s important for someone pitching multiple innings to stay warm (jacket) while not pitching or in the batter’s box.

Pitching with a sore, hurting, or even just tired arm should be strictly avoided, as that is a sign that the arm may already be injured and is especially susceptible to further injury. A big problem is that pitchers often won’t tell the truth because they would rather pitch more than get taken out. So coaches must watch for hints such as changed mechanics, reduced accuracy, reduced velocity, etc. Pitching performance usually declines when arms get tired or sore so it’s a logical time to pull a pitcher anyway.

Pitching too much seems like it should be easy to solve. Just pitch less. Pitching less frequently reduces wear and tear and allows recovery time. But there are several reasons this does not happen:

  • Arm injuries to ligaments, tendons, and growth plates are usually so gradual and painless that players, coaches, and parents have no idea anything is wrong until the damage is already done. A way to think of it: Heavy pitching for several weeks in a row causes the arm to be injured 1% by the end of week 1, 2% by the end of week 2, and 3% by the end of week 3. It is not until week 80 when the arm is injured 80% that it starts to hurt a little, and it isn’t until 100% that pitching is no longer an option. I totally made up these percentages, but the concept is valid. A pitching arm that is overused won’t hurt at first and the damage is gradual – you don’t usually get feedback of severe pain and discomfort until it’s too late.
  • Some kids love playing and never want to stop.
  • A coach’s desire to win makes it tempting to rely heavily on a team’s top 2 or 3 performing pitchers. This is somewhat tempered by pitch count limits enforced by most youth leagues.
  • Skilled pitchers are often persuaded to play throughout most of the year by joining all-star teams, select teams, or travel ball teams with looser pitching limits. Some players play for multiple teams.

And what about pitching practice outside of games? What about all the other throwing, especially if the pitcher does some catching? Parents must track player pitching and throwing time to make sure weekly, seasonal, and annual limits are not exceeded.

A concept I missed with the first version of this article is core strength—muscle strength in abdomen, back and pelvis. Many young athletes, and especially one-sport athletes, develop strong sport-specific muscles without corresponding core strength. Greater core strength corresponds with lowered risk of injury to pitchers.

By far the most difficult factor to understand is poor pitching mechanics. Pitching mechanics are the collection of body motions involved in the act of pitching. Some baseball experts believe that with proper mechanics, the chance of injury is very low regardless of the number of innings pitched. But youth pitchers rarely get expert instruction, so most will have mechanical issues that increase chances for injury.

One mechanical issue which requires no expertise is “overthrowing.” If you throw your absolute hardest with every pitch, you are much more likely to get injured.

“Throwing with all arm” is a common road to injury. A properly trained pitcher will generate throwing power mostly from leg-powered hip rotation. Getting proper hip rotation requires a strong core and getting several details right in throwing mechanics, including leg lift, bringing the arm back, and proper follow through.

I tried to learn proper mechanics from books and videos at first but found it difficult to assimilate. So I had my son refine his mechanics with seven one-on-one half hour pitching lessons with former minor league pitcher Josh Cephas. I observed so I could learn how to teach it. Leagues can facilitate the teaching of proper mechanics by requiring coaches to attend a pitching workshop once each year, or better yet having a professional pitching trainer who attends several practices for each team in the league.

The rest of this guide is a collection of specific actions that coaches, players, and parents can take that I’ve gathered from many different sources, including discussions with professional baseball coaches.

What coaches can do to keep their players’ arms healthy:

  • Never allow pitchers to exceed age-appropriate pitch count limits.
  • Try to minimize consecutive-day pitching. Ideally, each pitcher will have at least 48 hours rest between outings.
  • Pull pitchers who show signs of fatigue, even if far below pitch count limits.
  • Do not allow regular pitchers to catch much, or regular catchers to pitch much.
  • Do not allow pitching when a player has a sore or injured arm.
  • Have kids warm up with a little running, dynamic stretching, and light throwing before games.
  • Be sure to include “the core” in dynamic stretching with high knees, butt kicks, side shuffles, back pedals, etc.
  • Have players go through a warmup routine that includes 10-20 pitches before facing batters. It’s nice to keep the number of game-style warmup pitches low, as this number won’t be included in official pitch counts but does tire a pitchers arm.
  • At practices, do not have pitchers throw hard less than 48 hours before a game is scheduled.
  • Communicate with pitchers about pitching activities outside the team such as practice time, pitching lessons, or pitching on other teams. Coordinate to make sure each pitcher does not throw too many pitches.
  • As best as you can, learn how to teach proper mechanics. A good way to do this is to observe a professional pitching instructor teaching your player. At the very least, be sure to attend the annual pitching workshop put on by your league. If your league provides pitching trainers for use at some practices, use them.
  • Review mechanics of all pitchers at your first few practices. If you observe mechanical flaws, try to fix them. Especially ensure proper hip rotation as opposed to throwing with “all arm.”

What players can do to keep their arm healthy:

  • Get good sleep the night before a game
  • Avoid same day activities that use arm heavily (volleyball, football, etc.).
  • Warm up body with running or jumping jacks.
  • Warm up arm with dynamic stretches such as arm circles.
  • Warm up with gentle throwing before pitching, gradually throwing harder.
  • When pitching more than 1 inning, keep muscles warm when not on the mound or in the batter’s box. This means wearing a jacket on cooler days.
  • Always tell your coach if your arm starts feeling tired, sore, or hurts in some way.
  • Never pitch with absolute hardest arm speed—throw at around 80% to 90% of maximum possible. Do not get caught up in competing to be the hardest throwing pitcher with your teammates. Good pitching requires accuracy first and foremost and you lose that when you “overthrow” . . . and you’re more likely to get injured.
  • If doing pretend pitches with full throwing motion, always hold something. It could be a baseball or something at least as heavy (towel commonly used).
  • If a pitching outing results in pain or substantial soreness, ice shoulder and elbow for 10-15 minutes. Do this just after a game, not during. An arm ice sleeve makes this easy. My son has effectively used: Pro Ice Cold Therapy Youth Shoulder/Elbow Wrap, a model designed for players aged 9-13.
  • You want to practice pitching regularly to build up your arm strength for pitching. If you have not pitched for a few months or longer, be sure to work up to your regular pitching speed and pitch counts gradually over the course of a few weeks. Start by throwing every day for a few weeks, but not hard. Then do bullpen sessions 2-4 times per week.
  • Do NOT pitch every day. If you are pitching during 2 games each weekend during your baseball season, you may want to avoid practice pitching altogether, or at most a single practice session in the middle of the week. The idea is to allow time for your arm to recover.
  • Gentle throwing every day is fine and is a good thing to do the day after pitching.
  • On off days, do stretching and exercises designed to build up leg muscles and “the core.” Playing another sport that involves a lot of running will do some of this naturally. As kids get older and more serious about baseball, strength and conditioning routines should get more formal. See Strength and Conditioning Guide for Pre-High School Athletes (Especially Baseball).
  • Take at least 2 months off each year from any kind of throwing. Ideally, do another sport such as soccer or basketball in fall and winter while avoiding all forms of throwing.

What parents can do to help keep their player’s arm healthy:

  • Track player pitching and throwing time to make sure weekly, seasonal, and annual limits are not exceeded.
  • Ask your player frequently how their arm feels, most especially after they’ve just pitched during a game or at practice.
  • Get your player to understand how important it is to their future baseball success that they don’t throw hard when their arm is tired, sore, or hurting.
  • Recreation leagues have strict limits on pitch counts but travel ball teams do not. If your player is on a travel ball team, make sure that the coaching staff respects age appropriate pitching limits. If not, remove your player from the team.
  • Conventional wisdom would have you prohibit your player from learning breaking pitches such as curve balls (requiring wrist to turn) before they are 12. This is controversial, as studies show no significant correlation between breaking pitches and arm injury in youth pitchers, while some experts believe breaking pitches, and most especially sliders, pose risk to immature growth plates. However, improper mechanics with breaking pitches lead to injury at any age. If a kid learns to pitch a breaking ball from another kid or a book, he may learn it incorrectly. To play it safe, require that your pitcher learn breaking pitches from a professional pitching instructor. I have already promised this for my son for his 12th birthday present. He thinks ahead!
  • Learn about strength and conditioning (see Strength and Conditioning Guide for Pre-High School Athletes (Especially Baseball). Strongly encourage your young athlete to develop a regular workout routine based on healthy strength and conditioning principles.

What about static stretching?

Some coaches recommend static stretching. Static stretching is holding a pose that stretches one or more muscles (i.e. touch your toes), as opposed to dynamic stretches where you move your body (i.e. arm circles, butt kicks). However, scientific studies show that static stretching does not reduce chances of injury in sports like baseball, and in fact can hurt performance when done just before a game. There is also little evidence to support the idea that static stretching benefits pre-pubescent baseball players.

There is value in stretching for identifying sore muscles and increasing range of motion, and there are other activities where stretching is valuable like gymnastics, yoga, etc. However, static stretching should not be done before practices or games and certainly not before muscles are warm. The time for static stretching is after games and practices while muscles are still warm, or better yet during off days after muscle-warming exercise.

What I personally do with my son

There are many suggestions above and I do not always follow all of them. My son’s riskiest behavior over the past few years was going through an 18 month stretch of baseball with only one 5 week break. I tried to persuade him to take up a different fall sport but he wasn’t interested.

Fortunately, during this 18 month stretch he rarely pitched more than 45 pitches in a single day or 80 pitches in a week. He threw approximately 1500 game pitches in 80 innings during the last 12 months of that stretch, and perhaps 1000 more pitches in practice sessions. It helps that he throws a high percentage of strikes, which keeps his pitch counts down.

So far he has only had an occasional sore muscle below his armpit (Lattissimus Dorsi?). When this muscle starts to feel uncomfortable, I take him out immediately when I’m a coach.

At the end of the 18 month stretch, we did have him take a 4 month break from September through December to give his arm an extended rest. Now that I’ve done all this research, we’ll have him stop throwing a minimum of 2 months each year.

Further reading on Pitcher Safety and Disclaimer

Understand that I am neither a medical professional nor a baseball professional. The recommendations above come from extensive research and discussions mixed with a little experience but it’s entirely possible some details are wrong.

Please leave comments if you think any of my information is incorrect or incomplete and I will make corrections if I can corroborate the suggestion. Below are information resources that served as the sources for many of my recommendations.

I drew much of my information from two scientific studies released in 2011:

The Learning Curve: Little League Seeks to Address Concerns, Answer Questions about Curveballs and Overuse

Risk of Serious Injury for Young Baseball Pitchers: A 10-Year Prospective Study

MLB has a site with guidelines, risk factors, and discussion:

MLB Pitch Smart

Two guides on specific pitch count limits:

Position Statement for Youth Baseball Pitchers (ASMI)

Youth Baseball Pitching Injuries: USA Baseball Medical & Safety Advisory Committee, November 2008

A scientific paper describing the medical details of how arms get injured:

Baseball pitching kinematics, joint loads, and injury prevention


Author: Joe Golton

I’m a dad with a son who loves baseball. Professionally, I’ve been a software developer, investor, controller, and logistics manager. I now make my living from this blog, supplemented with occasional consulting gigs.

5 thoughts on “How to Prevent Youth Pitcher Arm Injuries”

  1. Great article, Joe. I would add two more injury-prevention tips based on my experiences in pro ball and now as a youth coach:

    1. Make certain pitchers are properly conditioned before throwing full velocity or pitching competitively.

    2. Concentrate on age-appropriate pitching skills.

  2. Joe, I’ve just discovered your posts, and they are fantastic. There’s a ton of information out there on youth baseball, but I find most of it to be dubious (usually because the source has something to sell–a bat, a book, a video instruction series, etc.). You posts do exactly what I would like to do with all the information out there if I had the time and the expertise. Thank you!

  3. You’re welcome, BMOS. I spend a great deal of time and effort on every single post so it’s nice to be appreciated occasionally. I do think there are some good videos out there on pitching and hitting mechanics but as far as text articles on other topics – I agree with you. The quality seems to be pretty low for the most part. It’s part of what motivates me to keep writing more posts about youth baseball. As my son gets older, I’ll get new ideas for posts that have to do with older kids.

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