Erin Foster was running toward a groundball at an indoor lacrosse game when she was pushed, sending her unprotected head into a wall.

"It basically cracked my skull," the 20-year-old Ann Arbor Pioneer High School graduate recalled. "They said it was a traumatic head injury, a level up from a concussion. I had to have surgery that night and I still have a scar on my head."

Would a helmet, like the ones worn by male lacrosse players, have helped?

"Yeah, probably," said Foster, who was unable to play for more than a year because of her injury and now attends Calvin College.

Helmets are not a required piece of equipment worn by women who play high school or college lacrosse. Just this year, the National Federation of State High School Associations allowed the optional use of two models of headgear beyond the padded headbands familiar to fans and players of the game.

According to Consumer Product Safety Commission data, lacrosse (both genders) was ranked No. 13 in terms of sports injuries that required trips to the emergency room for athletes between the ages of 13-17. Between 2002 and 2014, there were an average of 5,830 such injuries each year, and the most common injury was to the head ; female athletes were just 26.4 percent of the total.

In 2018, Florida will become the first state to mandate high school female lacrosse players wear protective equipment over their entire head. At least one coach there, in Fort Lauderdale, Florida, isn't in favor of the move.

"I do think eventually it is going to make things worse," St. Thomas Aquinas coach Samantha MacCurdy said. "I think it's going to make us more aggressive. I think a few more things the refs are going to let slide because we have the helmets on."

Kathy Westdorp acknowledged headgear has been a topic of discussion in lacrosse circles for the last few years. As a member of the US Lacrosse women's rules subcommittee and assistant director of the Michigan High School Athletic Association, she is well aware of the debate. She can also explain the rationale the governing body has against mandating the use of helmets.

"It is because we advocate for participant safety that we are cautious about the value of headgear in girls' and women's lacrosse," Westdorp said. "There are unintended negative consequences including that the use of headgear may fundamentally alter the nature of the game by inviting high contact and may possibly lead to more injury. The conundrum continues to be if requiring female lacrosse players to wear headgear will make the sport safer or, as a result of the phenomenon called risk compensation, actually result in more, rather than fewer, head injuries."

At least some in the sport, especially those who consider themselves purists, believe boys and men have made lacrosse much more violent at least in part because they wear helmets and shoulder pads.

"It's just like football," said Scott Marr, who played at Johns Hopkins and is in his 17th season as men's lacrosse coach at the University at Albany. He has a daughter, Jordyn, who plays on the Albany women's team.

"When they didn't have helmets and they were wearing no facemasks, you didn't have as many head injuries because you weren't going after the head," he said. "I think once you put a helmet on, it's almost like everybody says, 'We can go after your head because you have a helmet on.' I think that's what they're trying to avoid."

Dr. Jeffrey Kutcher, a neurologist and the NBA concussion program director, advises the NFL and NHL Players' Associations and helped to create the NCAA's concussion-related policies. He said he has seen female lacrosse players this spring who might have avoided a visit to his clinic if their heads had been protected.

"I would recommend the use of headgear because I see injuries that are preventable," Kutcher said.

Despite rules that are in place, and usually enforced, to penalize contact, it still happens. It certainly did during a high school game this spring in suburban Detroit when Cranbrook hosted Mercy.

"I was cradling and some girl went across my head and they called the whistle," said Cranbrook's Jaden Bertuzzi, whose dad, Todd, played in the NHL for nearly two decades. "So, that helped."

Foster was knocked unconscious for about a minute when her head collided with a wall. She sat out a year and returned to the field for her senior season in high school. But the sport she began to play and love in the sixth grade simply didn't feel the same anymore.

"I was kind of scarred and I would flinch anytime anyone got near me," she said. "I got hit a couple times in the head with a stick. They tried to get me to wear a padded head wrap that some girls wear in soccer, but I felt really goofy with it and I didn't want to be the only one on the field wearing it.

"If everyone had to wear headgear, it would be different. I know the argument against it, but it doesn't make any sense to me why you wouldn't to protect players' heads."