There are a number of risk factors that have been suggested as potentially harmful to a young pitcher. Exceeding pitch counts for games or weeks, throwing off-speed pitches at a young age, playing as catcher on the days not pitching and more could increase the risk for a shoulder or elbow injury. I think that many people would be surprised that where a kid grows up might influence that risk as well.

Recent studies suggest that pitching in warmer climates might actually increase a pitcher’s risk of suffering an ulnar collateral ligament (UCL) injury that needs Tommy John surgery one day.

Location of high school baseball and rates of Tommy John surgery

First, Brandon J. Erickson, MD and other researchers at Rush University Medical Center in Chicago identified the states in which every Major League Baseball player after 1974 played high school baseball. They determined the high school state for every MLB pitcher who had ever undergone Tommy John surgery as well. Then they separated the players into those who played high school baseball above or below the 33rd parallel. These states had average daily temperatures above freezing in January.

The areas considered to be warm-weather areas were South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Texas, New Mexico, Arizona, California as well as Puerto Rico, the Dominican Republic and other Central American countries.

Also read:
4 risk factors for youth pitching injuries
Pitching too many innings could end your baseball career

While 64.5% of all the MLB players since 1974 played high school baseball in cold-weather areas, over 56% of the pitchers who had undergone Tommy John surgery grew up in warm-weather areas. Not only did a significantly higher proportion of the surgically reconstructed pitchers come from warm-weather areas, but also they underwent surgery at younger ages and fewer years into their major league careers than did the cold-weather players.

Location of high school and college baseball and risk of UCL injury

Researchers from the University of Florida will present a study this month at the American Medical Society for Sports Medicine’s annual meeting that shows a similar trend. They found that high school pitchers who play in southern states are 6.2% more likely to tear the UCL in their elbows than northern high school pitchers. College pitchers at schools in the South have a 5.5% higher risk than their northern counterparts.

In fact, the UF researchers found that of all the Tommy John surgeries performed on pitchers in the SEC and Big Ten conferences in recent years, 40 pitchers in the SEC had Tommy John surgery compared to only 18 in the Big Ten.

Climate and percentage of hitters and pitchers in Major League Baseball

It might not just be a higher risk of blowing out an elbow, though. Pitchers from northern states might be more likely to make it to the major leagues in general.

Glenn S. Fleisig, PhD and James R. Andrews, MD studied all players on major league rosters at the end of the 2010 season. 63% of the hitters originally came from warm-weather climates. Only 56% of the major league pitchers came from those warmer areas.

When asked by Grantland’s Jonah Keri about the risks for Tommy John injuries, Dr. Fleisig suggested that overuse from pitching for years in the South could play a role.

“So there’s an interesting study: More of the successful, Hall of Fame–type pitchers come from up north,” Fleisig explained to Keri. “And more of the hitters come from everywhere — a lot of them are from the South. And yes, if I’m a team, and I could draft a pitcher who pitched year-round, I’d be very hesitant.”

The problem with pitching in a warm location

Obviously it isn’t the warmer weather itself that is harmful to a younger pitcher. It is what those warmer temperatures allow him to do that is risky.

We are finding more evidence that UCL injuries of the elbow result from wear and tear over a long period of time. The cumulative amount of pitching – not just over one game or one season but over many years – takes a toll on the pitcher’s elbow. Pitching year round from an early age increases that cumulative toll faster than only pitching seven or eight months a year, leading to more Tommy John surgeries at earlier ages.

Also read:
Do baseball pitchers from warm weather areas have a greater risk for Tommy John surgery?
What is causing the spike in Tommy John injuries?

The first group of pitchers who threw year round is just now entering the major leagues, and they seem to be arriving with damage already done to their arms. Keri notes in his Grantland article that more MLB pitchers underwent Tommy John surgery in 2014 than did pitchers in all of the 1990s.

Young pitchers need to take 3 to 4 consecutive months off from pitching every year. They can play other sports, but they need to give up pitching for another travel team for those months. They should definitely skip the showcase events held in the offseason too.

Just because they can pitch all year in warmer weather doesn’t mean they should. More is not always better.

Note: A modified version of this post appears as my sports medicine column in the April 9, 2015 issue of The Post and Courier.

References:
Erickson BJ, Harris JD, Tetreault M, Bush-Joseph C, Cohen M, Romeo AA.
Is Tommy John Surgery Performed More Frequently in Major League Baseball Pitchers From Warm Weather Areas?. Orthopaedic Journal of Sports Medicine, October 2014; vol. 2, 10.

Fleisig GS, Andrews JR. Prevention of Elbow Injuries in Youth Baseball Pitchers. Sports Health: A Multidisciplinary Approach. September 2012. 4:419-424

Keri, Jonah. The Tommy John Epidemic: What’s Behind the Rapid Increase of Pitchers Undergoing Elbow Surgery? Grantland. March 10, 2015.

Year-round baseball in the South could lead to more injuries, according to UF Health research. UF News. March 26, 2015.