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Should young pitchers throw curveballs?

While watching the Little League World Series, I couldn’t help but notice the number of curveballs being thrown. It seems like 1/3 of all pitches are curveballs. Should 11 and 12 year olds be throwing curveballs, and if not, at what age is it safe to throw them?

The Little League World Series and the Taney Dragons have captured the hearts of so many around the nation. They kept nearly everyone in the Philly area intrigued and watching the games from the edge of our seats.

However, while watching the Little League World Series, I couldn't help but notice the number of curveballs being thrown. It seems like 1/3 of all pitches are curveballs.  Should 11 and 12 year olds be throwing curveballs, and if not, at what age is it safe to throw them?

Let's start with the research.  Studies by Flesig et al. and Dun et al., both out of the American Sports Medicine Institute (ASMI), did not find an increased injury risk for youth pitchers when comparing curveballs to fastballs1,2.  Neither study found that curveballs were safe, they simply did not find a correlation to injuries.  Both studies were performed well, but limitations of the studies may have contributed to their findings.  Dun did not test pitchers in a game nor when pitchers were fatigued2.  Flesig's injury definition only included surgery or pitchers who "retired" due to an injury1.  This certainly limits the number of pitchers' injuries recorded.  Only recording surgeries, and not recording injuries that prevent a pitcher from throwing or pitching for a significant time greatly reduces the number of overall injuries.  A recent study by Yang et al. found an increased risk of pain of 1.66 when comparing curveballs to fastballs in youth pitchers3.  Although significant, throwing curveballs presented only a small increased risk compared to pitching with "arm tiredness" which demonstrated an increased risk of injury 7.88 in the same study3.

Although co-authoring the studies by Flesig2 and Dun2, Dr. James Andrews (renowned orthopaedic surgeon and medical director for the Andrews Institute) recommends that youth pitchers refrain from throwing curveballs until they have mastered the fastball and change-up and are at least 14 years old4.  This comes from his decades of treating baseball pitchers from youth leagues to the majors.

To say curveballs are safe is misleading; they are safer only if the pitcher has nearly flawless mechanics.  Many young pitchers have poor mechanics when throwing a fastball, and throwing a curveball greatly increases the chances for poor mechanics, especially when pitchers are fatigued.  Young pitchers are more likely to alter their mechanics to create a better curveball.  This will increase forces on young arms that are not fully developed leading to a host of upper extremity injuries.

While the research has not conclusively shown a connection between curveballs and injuries; it is safest for young pitchers to avoid throwing curveballs until they are more mature and can use proper mechanics.  According to Dr. Michael Ciccotti (Rothman Institute Orthopedist; Chief of Sports Medicine; Philadelphia Phillies Head Team Physician; and Expert Panelist for Sports Doc) "the general recommendation of most sports medicine specialists caring for these athletes is to avoid off speed pitches as adolescents; being careful to gradually increase exposure to curveballs and off-speed pitches as teenagers into high school."  

Throwing fastballs and change-ups; using good mechanics; and learning to throw strikes will develop effective pitchers and likely save many arms.


1)     Fleisig GS, Andrews JR, Cutter GR, et al. Risk of serious injury for young baseball pitchers: a 10-year prospective study. Am J Sports Med. 2011;39(2):253-7.

2)     Dun S, Loftice J, Fleisig GS, Kingsley D, Andrews JR. A biomechanical comparison of youth baseball pitches: is the curveball potentially harmful?. Am J Sports Med. 2008;36(4):686-92.

3)     Yang J, Mann BJ, Guettler JH, et al. Risk-Prone Pitching Activities and Injuries in Youth Baseball: Findings From a National Sample. Am J Sports Med. 2014;42(6):1456-1463.

4)     Injury Prevention/ Baseball: Andrews Institute (2006-2014). Available at: Accessed August 25, 2014.

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