The Truth about Curveballs and Injury Risk

Today in the United States, baseball and softball are extremely popular, with about 15 million kids participating annually in “America’s Favorite Pastime.”

Many of these young athletes dream of reaching the next level – high school, college or even the major leagues. While the quest for a competitive edge can prove fun, it also requires athletes to perform unique and taxing endeavors, such as throwing repeatedly as hard as their bodies can do it.

“Throwing involves a highly coordinated and explosive movement that incorporates the whole kinetic chain, from their toes to their fingertips,” says Forté’s Dr. Michael Bender, a former assistant to the Houston Astros team physicians who is now team physician for Butler University. “It puts a ton of stress on the body.”

Historically, baseball and softball coaches have tried to minimize this stress by delaying the addition of specific pitches, such as a curveball, to a young pitcher’s repertoire. The thought was that the complex pitch would put too much stress on a developing arm.

Bender says the data proves otherwise.

“The truth is that there’s actually less stress on the shoulder and elbow when throwing a curveball than a fastball,” says Bender. “It’s been ingrained in many people that you shouldn't throw curveballs until puberty, but there really isn’t good evidence against it. Studies don't show an increased risk of injury in those who throw curveballs at a young age.”

The key, he says, is understanding when an individual can safely put together the speed, spin and location precision necessary to deliver a curveball across the plate. Good core strength, throwing technique and neuromuscular control are all signs an athlete has the physical maturity needed to do it well. Bender also recommends a simple screening exercise that helps identify if kids have the balance, core strength and stability required for such a complex motion.

“We ask kids to perform a single-leg squat, similar to a pistol squat,” says Bender. “If they don’t have the balance, if they wiggle all over or if they fall, they’re probably not ready for the challenge of standing and pushing off one leg while maintaining proper repeatable throwing mechanics.”

Once a pitcher begins to incorporate curveballs, prioritizing age-appropriate pitch counts, proper rest and recovery periods, and arm care routines can help minimize the risk of injury.

“Think big picture,” says Bender. “Parents, athletes, coaches and trainers should be proactive about monitoring workload more than anything.”

While there is no proof that throwing curveballs increases the risk of injury to throwing athletes, paying attention to an individual's specific needs and physical development is essential for protecting their overall health and performance.

These recommendations have been excerpted from Coaches Corner, a free monthly webinar series for coaches, athletic directors and athletic trainers. The series, developed and presented by Forté, in partnership with IHSAA, aims to arm coaching and support teams with helpful information to consider when working with their athletes. Subscribe online so you don’t miss an episode.