This puts enormous stress on the elbow. A true curveball is an overhead topspin motion, which should look very similar to a fastball except for the wrist motion. Major league pitchers often say that a curveball puts no more stress on their shoulder or elbow than a fastball. Other things, like velocity and number of pitches thrown, seem to have more of an effect on shoulder and arm injuries than the type of pitch thrown. Equipment Young players should use safety equipment.
Most leagues gradually increase the hardness of the ball as the child ages.
The tradeoff is that softer balls tend to bounce more and ground balls can come up off the ground more quickly. Aluminum bats, which are under scrutiny in the college game for the velocity the ball gets coming off the bat, are not as much of an issue in the younger leagues. But they do present the same problem in high school as they do at the college level. There has been some good research showing that breakaway bases probably aid in minimizing lower extremity injuries. If players slide into the breakaway bases very hard or too late, the bases release and come out before an ankle is hurt.