Scientists at Brown University, looking into years of controversy about whether the lighter aluminum or carbon bats propel the ball too fast because of their higher bat-to-ball energy transfer -- the so-called "trampoline effect" -- say they found in the hands of young teen players lighter non-wood bats hit the ball at wood-like speeds.
There have been concerns faster ball speeds off the bat make the game both harder for the defense and also dangerous.
"Everyone wants baseball to be safe and enjoyable," said biomechanics scientist Glenn Fleisig, chair of the medical and safety advisory committee of USA Baseball, the nation's governing body for all amateur and youth baseball. "The time has come for us to have coordinated rules for bat performance in youth baseball, but the bat regulations for high school and up cannot be simply applied to youth baseball."
Researchers at Brown University, led by orthopedics Professor Joseph Crisco, hoping to gather scientific data relevant to younger teens, recruited 22 volunteer hitters ages 13 to 18 to take about 3,400 swings with 13 different youth baseball bats, three wood and 10 non-wood.
Among the 10 non-wood bats studied, only three allowed players to hit the ball significantly faster than the three wood bats, they found, and for the youngest teen baseball players, many of whom need lighter bats to participate at all, lighter non-wood bats did not launch the ball at significantly higher speeds than wood bats.
"At the youth level for the bats that we studied, even though there was a trampoline effect, the loss of momentum overcompensated for it so no matter how hot the trampoline effect was, the bats were so light they still were not outperforming wood substantially," Crisco said.
The findings should help in decisions about bat materials in youth baseball, Fleisig said.
"Professor Crisco's work is going to be the foundation of data for making regulations and recommendations for youth baseball bats going forward," he said.