Preventing Pitching Injuries in Youth Baseball

Alarming injury statistics

If your child is a pitcher, he/she has about a fifty-fifty chance of experiencing pain in his/her elbow or shoulder during his/her baseball career.

A 2001 study in the journal Medicine, Science, Sports & Exercise¹ found that athletes who pitched with a tired arm were 6 times more likely to suffer from elbow pain and 4 more times more likely to have shoulder pain than those who did not have a tired arm. 

A 2002 study in the American Journal of Sports Medicine² found:

• roughly half of the 476 youth pitchers studied reported elbow or shoulder pain at least once during the season.
• For each additional 25 pitches thrown after reaching the 50 pitch count, the percentage of pitchers experiencing pain increased. 
• The risk of shoulder pain was 2 and a half times greater for pitchers who threw more than 75 pitches per game
• The risk of elbow pain was 3 1/2 times greater for pitchers throwing more than 600 pitches per season 
• For pitchers who self-reported pitching while tired, the risk of elbow pain was 6 times greater and the risk of shoulder pain increased four-fold.
• Youth baseball pitchers who threw curveballs or sliders were at an increased risk of elbow and shoulder pain [Note: while two recent studies suggest that throwing a curveball actually puts less stress on the elbow and shoulder than throwing fastballs, some experts, such as world-renowned orthopedic surgeon Dr. James Andrews of the American Sports Medicine Institute (ASMI), still believe throwing curveballs at an early age can be dangerous; see #12 below].

A 2006 study in the same journal³ found that overuse was the overriding factor in the development of arm pain among pitchers in youth baseball. That study identified the following risk factors for injury:

• 50 plus pitches in a game: For each additional 25 pitches thrown after reaching the 50 pitch count, the percentage of pitchers experiencing pain increased. 
• 75 pitches in a game: The risk of shoulder pain was 2 and a half times greater for pitchers who threw more than 75 pitches per game
• More than 600 pitches in a season: The risk of elbow pain was 3 1/2 times greater for pitchers throwing more than 600 pitches per season.
• Pitching with tired arm: For pitchers who self-reported pitching while tired, the risk of elbow pain was 6 times greater and the risk of shoulder pain increased four-fold.
• Throwing breaking pitches: Youth baseball pitchers who threw curve-balls or sliders were at an increased risk of elbow and shoulder pain [Note: The 2011 position statement on overuse injuries⁴ issued by the National Athletic Trainers' Association urges "caution" in allowing younger pitchers to throw curveballs.   For more on the curveball debate, see #12 below and click here]

Elbow pain was related to:

• increased age
• decreased height
• increased body mass index (BMI)
• increased cumulative (season-long) pitch counts
• arm fatigue
• decreased self-perceived performance
• concurrent participation in weightlifting program
• participation in additional baseball leagues.  

Shoulder pain was associated with:

• increased number of pitches thrown in games
• increased cumulative pitch counts
• pitching with tired arm
• decreased perceived self-performance.

A 2010 study⁵ by researchers at ASMI found that:

• Pitchers who pitched more than 100 innings in a calendar year were 3.5 times more likely to be so seriously injured as to require elbow or shoulder surgery or retire due to injury.
• Playing catcher appeared to double or triple a pitcher's risk of serious injury, although the sample size of the study was not sufficient to establish that this trend was statistically significant.
• The cumulative risk of serious injury to a pitcher over 10 years was 5%.

Other researchers have found that:

• 26% of youth players and 58% of high school pitchers experience elbow pain (a 2014 study¹⁶ reported that only 26% and 20% of youth baseball players reported that their arm never hurt when throwing or the day after throwing respectively; that 30% reported that arm pain at least sometimes caused them to have less fun playing; 
• 29% of 9- to 19-year-old boys experience shoulder pain (according to one study) and between 32% and 35% in two other studies.  A 2010 study of high school pitchers found nearly 4 out of 10 experienced such pain.
• One out of five (19%) of Little League pitchers (age 8 to 13) in a 2011 study by researchers at the University of North Carolina reported pain in the elbow and/or shoulder in the previous 12 months.
• Nearly half (46%) of youth players (average age 15 years) said that at least once they had actually been encouraged to keep playing despite having arm pain.¹⁶
• Twenty percent of the players in the same study throwing for travel ball teams or pitching in "showcase" events (see #10 below) reported pain.
• The number of pitching-related injuries doubled between Little League and high school, mostly due to the higher number of innings and pitches thrown.

The epidemic of arm injuries suffered by youth baseball pitchers is reflected in the dramatic increase in the number of shoulder and so-called Tommy John elbow (ulnar) ligament-transplant operations performed by Dr. James Andrews at ASMI:

• 9 Tommy John elbow operations from 1995 to 1998
• 65 over the next four years
• 224 from 2003 to 2008
• 2001-2002: total of 13 shoulder operations on teens
• Over next 6 years, 241
• A five- to sevenfold increase in high schoolers requiring UCL reconstruction since 2000.

Three main risk factors

Research by the ASMI and others points to three principal risk factors for injury to youth baseball pitchers: overuse (number of pitches during a game, season, and a year), poor pitching mechanics, and poor physical fitness/physical conditioning.

1. Overuse: Most baseball arm injuries are not the result of a single traumatic event. Instead, injuries are believe to be due to the cumulative effect of microscopic trauma from the repetitive act of pitching. Overuse occurs throughout the course of a single game, season, or year in the developing baseball player. 
2. Poor pitching mechanics has been suggested as a possible risk factor for injury, but such a link has yet to be shown in bio-mechanical or clinical studies.
3. Poor physical fitness/physical conditioning.

Of the three, experts seem to agree that the number of pitches thrown coupled with the lack of appropriate rest periods are the greatest contributor to the increasing incidence of pitcher arm injuries. 

The 2010 ASMI study⁵ suggests that it is the number of innings (greater than 100 in a calendar year) that puts pitchers at greatest risk of serious injury.

Likewise, a 2011 study⁶ reported in the American Journal of Sports Medicine suggests that pitchers in warm-weather climates are increased risk for injury because of the excessive time they dedicate to pitching in a calendar year.

Finally, another 2011 study, this one by researchers at the University of North Carolina and commissioned by Little League, also found that the average number of innings pitched per game was a risk factor for shoulder injuries in youth baseball pitchers.

"The number 1 risk factor for UCL injuries is poor mechanics,"  Dr. Andrews told ESPN The Magazine. "The No. 2 factor is overuse.  And if you combine overuse with poor mechanics, you're doomed."   

Other risk factors:

• Participating in more than 8 months of competitive pitching (which is why USA Baseball and MLB, in their Pitch Smart program, now recommend that all pitchers, regardless of age and ability, take 4 months off from overhand throwing, with at least 2 to 3 months off consecutively. 
• Throwing more than 80 pitches per appearance
• A fastball speed of more than 85 mph
• Pitching either infrequently, or regularly with arm fatigue
• Starting at another position before pitching.
• A previous history of injury (five times greater risk of elbow or shoulder injuries)