When Shawn Nieto felt the hit, he clutched the football tight, making sure not to lose his grip, even as his 16-year-old body fell limply to the ground.

When Erica Nieto saw the hit, she sprinted from her seat in the stands, down near the sideline and screamed for her son’s attention.

When the trainers at Cleveland High in Rio Rancho, N.M., saw the hit, they ran onto the field to make sure their junior running back was okay.

This much, everyone agrees on. What happened in the seconds, minutes and days that followed the state semifinal playoff game ultimately led both sides to a courtroom. School officials say Shawn was knocked unconscious for 20 to 30 seconds. He suffered a concussion, they said, which meant under state law, he was forced to sit out seven days to recover — which meant he’d miss the following week’s state championship game.

But Shawn says he never lost consciousness, and his family insists he didn’t suffer a concussion. So they hired a lawyer and filed a motion in court last month, pleading with a judge to let Shawn play in the title game.

Cleveland High (N.M.) player Shawn Nieto, in the No. 10 jersey, heads into the locker room with his teammates at halftime of the state championship game, which he missed -- except for one play-- because of his concussion. (Gary Herron/Rio Rancho Observer)

The case highlighted much of the confusion surrounding concussions, particularly as it concerns children and teenage football players. In recent years, youth leagues across the country have changed the way they teach football. States have passed laws to ensure high schools monitor player safety better. And the NFL has tweaked its rules and aired public-service announcements to educate a football-crazed nation about head injuries.

Yet, there still remains uncertainty and inconsistency about head injuries in young athletes. Participation numbers continue to drop in many areas, and according to a Harris Poll last year, one in three parents lives in fear that their child will get a concussion, while one in four prohibits their kids from playing contact sports because of concussion concerns. The same poll found that 87 percent of adults can’t correctly define a concussion, and 37 percent say they’re confused about what a concussion is.

Parents have to sort through conflicting information. Doctors such as Bennet Omalu, the subject of the movie “Concussion” who is credited with identifying chronic traumatic encephalopathy (CTE) in football players, and Robert Cantu, who co-authored the book “Concussions and Our Kids,” have said children shouldn’t play tackle football until the age of 14. Many other concussion experts say the science doesn’t yet support such a drastic conclusion.

[For ‘Concussion’ doctor, the spotlight only gets brighter]

And while football families try to sort out the facts, science and the proper precautions, the Nieto family is among those who say concussion hysteria has made the sport’s decision-makers overcautious at times.

“That’s the bogey-man blanket they’re throwing in sports now,” said Peter Nieto, Shawn’s father.

By barring Shawn from competing, the family said the school district violated his constitutional right to due process, his state constitutional right to participate in extracurricular activities and interfered with his educational opportunities.

School district officials in Rio Rancho, meanwhile, say they were just following the law and protecting the young player’s health and well-being.

When a state judge heard the case last month and was presented with the evidence in an Albuquerque courtroom, he felt he had no choice: Shawn Nieto, who may or may not have suffered a concussion one week earlier, was granted a temporary injunction and allowed to play in the state title game.

Versions of events

Shawn began playing youth football at age 7. His father competed in the sport, and his siblings were athletes too. His older sister even wrestled for the school team.

“As a mom, of course you’re concerned about how dangerous this is,” his mother, Erica, said this month in the first interview the family has done, “but I’ve always been an active parent when it comes to this stuff, attending practices, games, events to ensure if there is an injury, I’m there and able to seek medical attention as needed.”

Peter has coached wrestling and junior high football and said he’s gone through specific training related to concussions. “I’m not a professional by any means,” he said, “but I do know what people are concerned with.”

Standing just 5 feet 5 and 140 pounds, Shawn took over his team’s starting running back position midway through the season and went on to run for 931 yards and 18 touchdowns. His Cleveland Storm team, a preseason favorite to win state, posted an undefeated record.

The Nietos said the school never gave any training related to concussions, but they were given an informational sheet and required to sign a form.

The team breezed through the season, and despite his size, Shawn emerged as a key contributor. In the team’s playoff semifinal game, Shawn says he remembers everything. The Storm led and were charging down the field. Coaches called for an option play, and Shawn took the ball and began to make a cut. He saw an open field.

“I thought I was going to score,” he said.

But Shawn was yanked down by a horse-collar tackle, and before he hit the ground, another player crashed into him, their helmets colliding.

Shawn lay still on the ground. Trainers hovered over him. They say he was unconscious. Shawn says the wind was knocked out of him and he was merely catching his breath.

He eventually rose to his feet and when he reached the sideline, he gave his mother a thumbs up.

Team trainers administered a memorization test, and he correctly recalled two of the three words he was told to remember. He said he was distracted watching the game and missed one. He was given a balance test, too, and says he passed.

After the game, Shawn told his parents he felt fine. He didn’t have a headache, he said, and didn’t ask for medicine. He rode a bus three hours back to school, and coaches then allowed him to drive home alone from there.

“If it was that serious, I’d hope they’d notify the parents that there’s some major concern,” Erica said.

Shawn said he was told the next day at school that he would have to go through the concussion protocol and would be unable to play in the state championship game.

Peter drove straight to the school when he heard the news. He talked to coaches, the athletics director and the school’s athletic trainer. The trainer explained Shawn was unresponsive and had been knocked unconscious. The parents say they were never given any paperwork to support the school’s assessment and never observed any symptoms that Shawn had suffered a head injury in the game.

“We’re not rookies,” Peter said. “We know what a concussion is.”

‘There’s no wiggle room’

While concussions and the degenerative disease CTE have made headlines and been linked to football greats such as Junior Seau and Frank Gifford, researchers are still trying to understand the risks football might pose to young people.

[Frank Gifford’s family says Hall of Famer suffered from CTE]

“The younger we go, the less science there is,” said Harry Kerasidis, a neurologist who authored the recent book “Concussionology: Redefining Sports Concussion Management For All Levels,” “and we have kind of extrapolated from studies that were done on older individuals.”

Kerasidis explained that there are two schools of thought: (1) A child’s brain is still developing and any trauma can be especially harmful; (2) children are smaller, slower and perhaps unable to deliver as much force in their collisions as older players. While recent research has found CTE widespread in a former player who was 25 years old at the time of his death, researchers are working to understand definitively the long-term effects of head trauma suffered by young players.

“We really don’t yet have the level of science that we need,” said Gerard Gioia, who heads the division of pediatric neuropsychology at Children’s National Medical Center in Washington and directs the Safe Concussion Outcome Recovery and Education Program. “We don’t know what the difference is between a 7-year-old brain taking a blow or hit versus a 13-year-old versus a 17-year-old. We really need those studies to be done.”

Nieto’s family was eager to learn Shawn’s condition and made a doctor’s appointment for the following day. Shawn met with a doctor and exhibited normal cognitive ability, orientation, memory recall and concentration, according to the family’s court filing.

Backed by the doctor’s recommendation, the Nietos became even more determined for him to play in the state title game and explored their legal options.

“If something looks bad, it doesn’t mean it’s really that bad, you know,” Peter said. “This just happened at an emotional milestone in our son’s life, so we were going to do whatever we thought we could to get his voice heard, to not lose this opportunity.”

The school district, meanwhile, was just as adamant that Shawn had been injured and state law required he sit out seven days.

“There’s no wiggle room,” said Bruce Carver, the school district’s athletics director. “If somebody thinks it is [a concussion], we go the safe road and keep him out.”

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All 50 states, and the District, have passed laws that address concussion safety in youth sports, but the particulars vary. A concussion might be diagnosed differently in South Carolina than Colorado, and the required recovery might be different in California than Pennsylvania. Arkansas allots money for a program but has no standards in place. Wyoming doesn’t require parents to sign a consent form. Only a handful, such as New Mexico, have a mandatory waiting period before a player can return to action.

While New Mexico’s statute was hailed as one of the toughest when it was signed into law in 2010, opinions vary about whether a mandatory waiting period is effective. A 2009 study looked at 635 high school- and college-aged concussed football players and found that the waiting period “did not intrinsically influence clinical recovery or reduce the risk of a repeat concussion in the same sports season.”

“This concussion law is just one size fits all,” Erica said of New Mexico’s statute. “It’s expected to fit every situation, and it really does not allow for how to address a conflict — how do you get an independent evaluation? There’s no wiggle room at all, and I think there needs to be.”

Still at odds

State district Judge Alan Malott scheduled a hearing for Dec. 4, barely 24 hours before the championship game was schedule to kick off. Neither the school nor the school district showed up in court, and Malott had at his disposal one key piece of evidence: Shawn’s doctor clearing him to play. Malott granted the injunction.

“The fact that the doctor said he was fine and never was hurt was obviously pretty substantial evidence,” Malott said in a phone interview. “The school didn’t even show up, so I didn’t have the benefit of a coaches’ report or anything like that.”

The morning of the title game, though, Karen Ortiz, the physician who examined Shawn, sent a letter to the school district, rescinding her opinion and saying the family was not forthcoming with the extent of Shawn’s injury.

“Had I understood that there was a loss of consciousness, I would have never provided medical clearance,” Ortiz wrote in a letter first published in the Albuquerque Journal.

A spokesperson for Ortiz’s employer, Lovelace Health System, said the doctor could not comment on the case, citing privacy concerns. Neither the Nieto family nor the judge say they have ever seen the letter.

The Cleveland Storm took the field that night, and Shawn was in uniform alongside his teammates. But he’d missed the entire week of practice, and coaches didn’t use him in the game. Shawn’s lone appearance was for a brief fourth-quarter kickoff. His Storm team posted a 48-35 win to capture the title and cap a 13-0 season. Shawn’s replacement ran for 200 yards and scored a touchdown.

Shawn said watching his teammates win the state championship without him was bittersweet. Many students at his school didn’t understand why his parents took to the courts, and the school hallways this winter have not always been pleasant. His wrestling season has since started, though, and he hopes to regain his starting running back job next fall as a senior.

The Nietos remain upset with the letter of the law and the school’s application of it. They’re still confident Shawn never suffered a concussion. School officials overreacted, they say, and Shawn suffered because of it. They plan to write a letter to the local school board suggesting ways the rules could be improved.

Carver, the school district’s athletics director, said the school and team officials “could’ve done a better job communicating,” but they still support the spirit of the law.

“We feel like we did what’s best for the kid and trying to protect him,” he said.