“After the series, I got out, looked at the scoreboard and it was kind of blurry,” Decius said. “I started to feel a headache.”

Student athletic trainers noticed Decius acting confused as he took a breather. They told trainer Rheisa Burke, who gave Decius a quick head trauma evaluation on her iPad called the King-Devick test.

“He dazed out on me,” Burke said.

Decius had a concussion. Burke and coach Earl Tillman ordered Decius to the bench. Three weeks later, after following a strict recovery protocol, Decius returned to action during the playoffs. Last month, the Tornadoes won their fourth consecutive state championship, and Decius was the star on defense, returning an interception 100 yards for a touchdown, making 10 tackles and forcing a fumble.

Decius, a senior, might not have been healthy enough to play his finest game in his final high school contest if not for the alert actions of the trainer and coaches who oversee the safety of the football team. They are key players in a pioneering partnership between Miami-Dade County Public Schools and the University of Miami, which has made concussion awareness, prevention and treatment a priority for the county’s 12,000 student athletes.

UM and the country’s fourth-largest public school system work together to catalog and treat concussions in every public high school and for every sport — an undertaking that is one of a kind in the nation, according to its founder. Since the initiative began about four years ago, the incidents and outcomes of almost 600 concussions have been recorded.

That number represents only the minimal number of concussions suffered by high school athletes — the ones formally reported at 36 public high schools. Many others, for a host of reasons, likely go undetected or undocumented, and the program doesn’t track about 55 other private and charter schools that field contact sports teams across the county.

“It’s the tip of the iceberg,” said Gillian Hotz, director of the concussion program at UM and the driving force behind the data-tracking effort.

Though it’s early and Hotz is still working to improve response from some schools, the program already has produced three school years of information-rich data. The numbers have begun to shed light on how often kids suffer concussions, why they get hurt, how long it takes to recover and — most important — how to prevent them.

“What we strive for now is, how do we make the game as safe as possible?” Hotz said. “This has allowed us to see exactly what kind of numbers we have in the county, and to work with athletics to figure out, do we need to improve turf, or the field? Are helmets being fitted properly? Is sideline management happening?”

Hotz’s research shows that nearly 200 concussions were reported last school year — a tiny fraction of athletes playing high school sports — and that the impacts of a seriously rung bell can extend beyond the field into the classroom. After a concussion, it can be tough for kids to even crack a book for days or weeks.

Unsurprisingly, the vast majority have been in football, but they also have been recorded in a dozen contact sports, from girls’ soccer to water polo.

Florida in recent years has made efforts to make sports safer — there are limits on contact during football practice, for instance, and female lacrosse players now have to wear headgear.

Florida High School Athletic Association Executive Director Roger Dearing believes sports are safer than in past years.

“I think now more instances of concussion are being recognized,” Dearing said. “I don’t think they’re happening more often. In fact, the opposite.”

That could be the case, but the reality is that no one can say for sure. Until Miami-Dade paired up with UM, probably only one other Florida county, Orange, made any effort to track brain injury stats on high school fields and courts. While researchers, the media and even Hollywood with the movie Concussion have devoted increasing attention to brain injury in pro football players — youth sports largely remain a missing piece of a complex medical puzzle.

The hope is that efforts like Miami-Dade’s can help explain what parents and researchers alike want to know: At what age are kids most vulnerable? How many concussions is too many? And, perhaps most importantly, what are the long-term impacts to the brain?

“There’s a lot we don’t know,” said Dawn Comstock, an associate professor of epidemiology at the University of Colorado Denver who has been tracking high school sports injuries for a decade.

THE TRENDS

After three years, the UM program has begun to show some broad trends.

Most reported concussions — about 70 percent — have been in football, which also has the largest number of athletes by far, with nearly 1,600 varsity players last year. Among football players, linebackers were most likely to be concussed, with 67 injuries reported. Wide receivers were the next most likely. They tallied 47 concussions.

Soccer and basketball tallied the second- and third-most concussions, accounting for about 12 percent and seven percent of the total, with more than a half dozen other sports trailing behind.

One area that has shown a significant increase has been in girls’ sports, jumping from 15 the first year to 39 last year — a 160 percent increase.

It’s hard to know how much importance to make of such year-by-year changes, however, because the numbers clearly show wide variances in reporting between schools. Coral Gables High, with a student population of 3,400, leads all Miami-Dade schools with 56 reported concussions, followed by South Miami at 40. At the bottom were North Miami Beach and South Dade, both of which have football teams, with two and four reported concussions for all sports.

Hotz believes the diligence of individual athletic trainers, who are responsible for compiling the numbers, explains the widest skews between schools and said she is working on training programs to encourage more uniform reporting standards. The size of schools, number of sports teams, types of gear and other factors also can add up to more or fewer reports.

There is also another, perhaps bigger, hurdle to collecting accurate statistics: Student-athletes who face enormous pressure to stay in the game and make plays that might elevate them in the eyes of college scouts. Just ask Benedict Hyppolite, offensive coordinator at nationally ranked Booker T. Washington, a Miami school that consistently sends players to Division I programs on scholarship.

“These kids want to play. They need game stats and film,” Hyppolite said. “They think, ‘If I’m sitting down, the guy behind me can take advantage of the opportunity and supplant me.’ That’s what they’re afraid of, more than a concussion.”

DEFINING CONCUSSION

Michele Benz keeps a Diet Coke bottle on her desk. The Miami Palmetto High trainer uses it to demonstrate to young, ambitious athletes what a concussion does to your brain.

She shakes it so the carbonation fizzes. While the bottle still looks the same, clearly there’s a violent reaction inside. Something similar happens to your brain, though you can’t see it, she said.

“That’s a little scary,” Benz said.

A concussion is an invisible, traumatic brain injury that can even escape detection in a CT scan. It happens when the brain is jolted inside the skull, stretching and twisting after a tackle, collision, blow or header. Young people are especially susceptible because they have thinner skulls and weaker necks. A study by the National Research Council and Institute of Medicine has shown that high school football players are almost twice as likely as college players to suffer a concussion.

Concussions are treatable and most go away within days or weeks. But serious cases can linger for months or even years.

“Some kids have a lot of symptoms. Some kids don’t have symptoms at all. It’s like snowflakes,” Hotz said. “They’re all shaped differently, and there’s something different about each one.”

Miami Central High trainer Elise Carlson treats the aches, pains, pulls and sprains of 450 athletes. When she teaches them about concussions, she tells them, “It’s your life versus your sport. Don’t hide it if you’re hurt.”

“Sometimes you see a really dramatic hit and they get right up and sometimes you see a hit that doesn’t look bad and they’re down on the field,” said Carlson, who recently treated two wrestlers for concussions. “The kids say, ‘Uh, oh — he rang the bell.’”

Symptoms — headache, nausea, dizziness, drowsiness, inability to concentrate, sensitivity to light and noise — tend to be worse and last longer for girls. In Miami-Dade, girls had more concussions than boys in soccer and basketball over the past two years, according to a UM analysis. That difference is echoed in national research.

In a class-action lawsuit filed by parents and players, it said the U.S. Soccer Federation, American Youth Soccer Organization and FIFA were negligent in treating and monitoring head injuries, the plaintiffs said nearly 50,000 high school soccer players sustained concussions in 2010 — more players than in baseball, basketball, softball and wrestling combined. U.S. Soccer resolved the case in November by announcing a prohibition on heading the ball for players age 10 and under.

The Coral Gables girls’ soccer team began this season with five players on the bench with concussions. Brianna de la Osa, a sophomore forward, was upended by a goalie and landed on the back of her head on turf at Traz Powell Stadium. Three days later, she headed the ball awkwardly and immediately felt dizzy. By the next day, she was nauseous and befuddled.

“Monday in math class I couldn’t understand anything my teacher was saying,” said de la Osa, who failed a series of cognitive tests at the doctor’s office.

She missed a week of school while enduring throbbing headaches that made her want to throw up. She was told to turn off her brain, and not watch TV, read or text.

“Don’t think, basically,” she said. “I lay in bed and looked at the ceiling. I thought about whether I’d ever be the same. It’s really scary. I felt like I was losing my mind.”

It took a month until de la Osa could return to soccer.

BRAIN DISEASE, NFL

Attention on concussions has exploded in recent years in conjunction with coverage of the sad and alarming stories of retired NFL players who have committed suicide or had their lives waylaid by depression or dementia. In 87 cases, ex-NFL players were diagnosed post mortem with Chronic Traumatic Encephalopathy (CTE), a degenerative disease caused by repetitive concussive and sub-concussive hits to the head. Former Chicago Bear Dave Duerson shot himself in the chest in his Sunny Isles Beach condo and left instructions that his brain be donated to Boston University’s Brain Bank. A year later, former Dolphin Junior Seau also committed suicide and CTE was found in his brain.

For years, the NFL denied a link between football and chronic brain damage, which is the subject of the recent movie Concussion, starring Will Smith as courageous forensic pathologist Dr. Bennet Omalu, who first discovered CTE in ex-Steeler Mike Webster in 2002, then stood up to the NFL as it tried to discredit his findings.

The Concussion Legacy Foundation and its leader Chris Nowinski, a former football player and pro wrestler, has taken an activist stance on what it calls the “concussion crisis” by spotlighting CTE research on NFL players and expanding its preventative scope to youth sports.

The disease has been found in the brain tissue of 131 out of 165 people who played football as pros, semi-pros, in college or in high school, according to the Boston lab. But Hotz emphasized that concussions are treatable, and while one concussion can increase the chances of having another, teen athletes should not worry about long-term brain damage.

“To make the connection between CTE, which is a disease, and youth sports is way too early,” Hotz said. “The positives of playing sports in high school far outweigh the negatives. You have to be careful not to exaggerate while we’re building the evidence.”

THE PROGRAM

Part of that evidence-building is happening in Miami-Dade schools.

The results provide valuable insight into who is getting injured and why. Last year, when Hotz noticed a spike in football concussions at one school, she called the trainer.

“He said, ‘I think I know why. It’s the helmets. The kids are swapping helmets.’ Now, because we knew that, I sent my guys there. We worked on fitting helmets with the team, and the problem went away,” Hotz said.

Miami-Dade has tracked student injuries for years, but only for insurance purposes. It wasn’t until 2011 that the school system paired up with UM to share its data.

Miami-Dade’s tracking program works because every high school has a paid, full-time athletic trainer on staff who is required to submit concussion reports to UM. Across the country, much of the concussion research at the high school level relies on athletic trainers to collect and report data, since they have the expertise to spot injuries and they attend sporting events as part of their job.

Without athletic trainers, Hotz said, collecting the information needed can be expensive and complicated. But that’s not the case in most counties, including neighboring Broward County. Less than 40 percent of high schools nationwide have full-time athletic trainers, according to the National Athletic Trainers’ Association.

The partnership with UM began thanks to former Ransom Everglades soccer player David Goldstein, trainers Benz and Mary Medina, Greater Miami Athletic Conference Executive Secretary Cheryl Golden and Hotz, who has been studying concussions for two decades.

Goldstein, now a junior at Princeton University, sustained multiple concussions in high school and dedicated himself to raising money for concussion testing and lobbying for a 2012 state law that requires players to get a doctor’s clearance before returning to play. All 50 states now have similar laws.

“When I got hurt, I had very bad symptoms, namely headache, sensitivity to lights and sounds and nausea. I was very sick for four months and I went looking for help,” said Goldstein, 21. “When I looked back, I didn’t want other athletes to be as confused as I was.”

Goldstein’s efforts have had a ripple effect. His alma mater donates about $500 per public high school for the cost of administering a pre-season baseline test called ImPACT to athletes in contact sports. This year, the district also piloted the King-Devick test, which is a timed two-minute number-reading exam.

Both tests provide a baseline score that trainers can use to make comparisons and help determine whether a student has a concussion.

“It’s so much simpler to be able to hop off the field and take the test, and have a much clearer idea about what to do,” Goldstein said. “Without the ImPACT test, it’s more of a guessing game.”

Once a student is hurt, Miami-Dade follows step-by-step protocols to diagnose and treat concussions. Getting back into the game is a process monitored by trainers. Students are prescribed what is called a gradual return to play, where they are allowed to participate in progressively more intensive practice if symptoms do not recur.

Sometimes that can take months.

Ingrid Espinoza-Hueck was a freshman swimmer at Miami Senior High when she was startled by a coach screaming at her to switch lanes, slipped off her starting block and landed on her face. The thud of her head on concrete was the loudest sound on the pool deck. Coach Tim Tornillo ran to his swimmer.

“He thought I might be dead,” Espinoza-Hueck recalled.

She woke up in Tornillo’s arms with the feeling that her head had been crushed. It was only the beginning of an agonizing six-month recovery for Espinoza-Hueck.

Before she got better and resumed playing water polo last spring, she developed a stutter and had random nosebleeds. Her handwriting deteriorated to a scribble and she had to wear sunglasses everywhere.

Only at the end of the fall swimming season did she overcome her fear of climbing atop the starting block. She took to diving from the side of the pool during races.

“Every time I tried to step up my legs would shake or I’d cry,” Espinoza-Hueck said. “Now I’m back to normal.”

Getting back to normal often includes a visit to the UHealth Sports Medicine Concussion Clinic at Jackson Memorial Hospital in downtown Miami. Twice a week, Hotz and her partner Dr. Kester Nedd tend to a parade of impatient student-athletes. Though students can get clearance from their own doctors, trainers refer athletes to the clinic doctors for their renowned expertise.

Evelyn Roque wore her soccer jersey to her last appointment. The 15-year-old American High sophomore was sidelined for weeks after multiple bumps to the head during a game. The last hit — a ball to the face — forced her to her knees. Her coach rushed over and Roque collapsed in tears.

“I haven’t practiced. I haven’t played. For me, it’s been long,” she said. “I just want to get back to play, but with a more cautious attitude.”

Dr. Nedd shone a light into each of her eyes, tracking how well she could follow the bright point. He ordered Roque to spin around in circles and walk heel-to-toe across the room to test her balance. Hotz read her latest ImPACT scores and delivered the news that Roque would be able to return to play the following week.

“You got your daughter back,” Dr. Nedd told Roque’s parents.

LOOKING FORWARD

Prevention is a major aspect of training strategy by coaches such as Roland Smith, coach at Central, which has won four consecutive state football titles. Concussion awareness has increased “100 percent,” he said, since he was a player, and since one of his assistants, Sabbath Joseph, was a player and sustained five concussions during his high school and college playing career.

“I’m not about to put a kid in because we need to win a game. It’s never worth it,” Smith said. “I have a 13-year-old son who plays football and he had to sit out and he wanted to play. I told him, ‘If the doctor says you can’t play, you can’t play. Period.’ ”

Proper tackling technique — which means not using the head as a spear — is crucial, said Smith, who did not have a concussion this year among the 65 players on his regular season roster, which grew to 84 on his playoff roster.

“We don’t assume any kid knows how to tackle correctly, even if he’s been here four years and playing for 10 years,” he said. “We teach head placement, not using the crown of your head, keeping your head up and not down. We emphasize safety because we don’t want to see our kids in a neck brace or knocked out.”

Hotz said the next area the data can illuminate is the timing on an athlete’s full return to the classroom. She found that it takes about 10 days for some athletes to get over their symptoms. In certain sports more time out was required, according to UM data: 15 days for baseball, and 13 for football, softball and wrestling.

Concussion symptoms can be debilitating for students with heavy class loads. Computer screens pose a problem, yet students are required to take at least one virtual class to graduate. Many athletes said their grades declined while they recovered, and teachers weren’t always sympathetic.

“The coaches are well informed but the classroom teachers tend to ask, ‘Is this real?’ ” said Tornillo, the Miami High swimming coach and an Honors World History teacher who once saw a backstroker sustain a concussion after hitting his head on the wall during a flip turn. “These kids coming back from concussions need to take breaks and it isn’t always met with a smile. You can’t expect them to read much under those fluorescent lights or on a computer screen. The next step is working with teachers on academic protocol.”

John Smithies, a Coral Gables High junior, made the heartbreaking decision to quit playing football this season after sustaining four concussions since freshman year.

One was caused after he got hit hard in the head in two practices within three days.

During summer practice, the linebacker endured a whiplashing collision and was diagnosed with another concussion. The headaches returned. So did insomnia. His doctor and parents advised him to stop playing. He watched a preseason presentation on concussions. A week before school started he told his coach the risk was too much to bear. He cleaned out his locker.

“I’ve loved playing football since I was 8 years old,” Smithies said. “I really miss it — working hard with my teammates and the rush of a game. I’ve thought about going back. But I think I made the right choice because of my history. I don’t want to end up messed up and dependent on my family.

“I’ve played through injuries in the past. Like my dad said, you can always fix a broken arm. But you only get one brain.”

Miami Herald reporters Andre Fernandez and Manny Navarro contributed to this report.