ENDEAVORS
Curveballs and Sliders:
Careful With the Wrist-Twisters

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Pitchers get hurt. That’s a fact of baseball. And anyone who’s played the game has an opinion about why: The pitching motion is unnatural, curveballs and split-finger fastballs ruin elbows, pitch counts are too high, some pitchers aren’t built to last.

Three UNC researchers were a little more scientific about it. They surveyed thousands of players from youth leagues, high schools and colleges. Turns out that the type of pitch a player throws doesn’t matter nearly as much as how often the player throws any type of pitch.

The curveball has long been blamed for arm injuries because it requires the pitcher’s forearm to twist just before the ball is released. A lot of parents and coaches don’t let their Little Leaguers throw curveballs. Some parents have even pressured Little League Baseball to ban the pitch. The organization has never taken that step, but it did want to find out why its pitchers were complaining of achy, tired and injured arms. Little League Baseball teamed up with researchers from Yale and UNC, including Johna Register-Mihalik ’06 (MA, ’ 10 PhD), a postdoctoral research associate in the department of exercise and sport science who collected and analyzed much of the data.

Between 2006 and 2010, the researchers surveyed hundreds of Little Leaguers. Register-Mihalik also worked with athletic trainers to survey several hundred high school and college players.

Register-Mihalik’s team found that Little Leaguers who threw curveballs didn’t experience pain or get injured any more than the Little Leaguers who didn’t throw curveballs. But another pitch seemed to be causing trouble.

Parents and
coaches don’t
want young kids
to throw curveballs
because the technique
requires pitchers to twist
their wrists. It’s like turning
a doorknob hard while throwing. The idea is to
make the ball drop dramatically as it approaches
home plate. The curveball is slower than a fast-
ball, so it has a second level of deceptiveness. But
throwing a curveball puts torque on the elbow.