Hahn is among nine players since 1982 who were paralyzed as a result of headfirst slides, according to the National Center for Catastrophic Sport Injury Research at the University of North Carolina in Chapel Hill.
Countless ankles, feet and legs have been broken from what would have appeared to have been harmless feet-first slides. The American Academy of Orthopaedic Surgeons recommends that players under 10 shouldn’t be taught to slide, and Little League bans head-first sliding except when the runner is retreating to a previously held base.
David Peters, an engineering professor who studies baseball physics at Washington University in St. Louis, said his research suggests headfirst sliding gets the runner to the base faster, but barely. That’s because the tips of the runner’s fingers are farther from his center of gravity, giving him a 6- to 8-inch advantage when he stretches out for the bag.
That advantage, of course, is reduced if the runner clenches his hands into fists as he goes into the bag to avoid finger injuries.
Either way, “it’s a millisecond of time, but you give yourself some extra distance,” Peters said.
Jose Reyes of the Miami Marlins said he started sliding headfirst because he injured an ankle going feet-first in 2003. He said he learned the style as a little kid and has fun doing it.
“When you play baseball and you’re a little kid, you love to dive,” he said. “I’m 28 and I still have that passion. I love it because I feel like I do something for the team.”
Erstad said he and other coaches avoid having players work on sliding at practice because to do it right, it has to be done at full speed and it’s hard to simulate game conditions without risk of injury.
Erstad said he wants his players to slide the way they are most comfortable. “If that means headfirst, knock yourself out,” he said.
“We’re going to stress feet-first,” Erstad said. “I’m not going to take a kid out of a game if he goes head-first. There are things on a baseball field that happen or are done out of instinct.”
AP Sports Writers David Ginsburg in Baltimore and Steven Wine in Miami contributed.