bowman1.jpg

San Francisco 49ers inside linebacker NaVorro Bowman (53) is carted off the field during the second half of the 2013 NFC Championship football game against the Seattle Seahawks at CenturyLink Field.

(Steven Bisig/USA TODAY)

The Denver Broncos opened their 2013 season on Sept. 5 against the Baltimore Ravens, and the violent slog of an NFL season began.

With unnerving regularity and from preseason on, at least one player a month saw the operating table, eight Broncos in all. Forty-six players appeared on the team’s weekly injury report, including one listed all 19 weeks (offensive guard Chris Kuper) and another, safety Duke Ihenacho, whose body was ravaged piece by piece, with knee, head, ankle and thigh injuries.

Then came calamitous November, when safety Rahim Moore had a procedure on his lower left leg to stop bleeding in the muscle sheath, and Derek Wolfe, a defensive end, suffered seizure-like symptoms on a team bus. (Head coach John Fox needed emergency medical care, too, undergoing surgery to replace his aortic valve.)

The violent, physical nature of football has been around since the first kickoff. And recently, the NFL has been forced to confront its dark side. Retired players, now crippled or suffering from brain diseases associated with repetitive blows to the head, have come forward, putting a scorching light on the dangers of America’s favorite, ferocious pastime.

The sport has taken strides to make the game safer, with penalties for dangerous hits, a concussion protocol and hefty fines for flouting the guidelines.

But the state of football — with its constant crashing bodies and injury risks — is under scrutiny again this week as the Broncos prepare to face the Seattle Seahawks tomorrow in Super Bowl XLVIII at MetLife Stadium. Denver, with its injury-riddled roster, will take on a Seahawks team renown for its punishing defense, led by a secondary ominously known as "The Legion of Boom."

The sheer numbers leap out.

According to data released this week by the NFL, between this year’s preseason and regular season, 57 players suffered season-ending torn anterior cruciate knee ligaments, and 228 concussions were reported, including 11 between the Broncos and Seahawks. Concussions are down 13 percent from last season, but it’s unclear if this is an anomaly or the start of a trend.

Despite the increased outward attention to health and safety, doctors, former players and sports psychologists say the NFL and its culture continue to barrel along at an increasingly hazardous pace. The NFL often seems to be working on opposing tracks, trying, it says, to corral injuries while promoting the images and even the noise of hitting and tackling at its fiercest. The guttural groans and grunts in the trenches, and crashes of helmets and pads colliding, have become America’s unofficial Sunday soundtrack.

That players are bigger, stronger, faster — and more dangerous than ever — cancel out many of the safeguards, some say.

"As players become much more physically conditioned, physically strong and mentally strong, they’ve been much more aggressive and assertive in being able to execute and get the job done," said Charlie Maher, a Professor Emeritus of Applied Psychology at Rutgers who has served as a sports psychology consultant for the Jets and Cleveland Browns. "You put all of that together, it does set the conditions for a greater risk of injury."

According to the NFL Physician’s Society website, NFL players are vulnerable to orthopedic and muscle injuries and "concussions, blunt injuries to the chest such as cardiac contusions, pulmonary contusions, broken ribs, abdominal injuries, splenic lacerations and kidney injuries."

Gruesome injuries have become almost routine, including frightening hits that led to torn knee ligaments for Dolphins tight end Dustin Keller, Patriots tight end Rob Gronkowski and, in last Sunday’s NFC Championship Game, 49ers linebacker NaVorro Bowman.

"It’s the human missile mentality," said Vincent McInerney, director of sports medicine at Saint Joseph’s Regional Center in Paterson. "We’re not human missiles and we shouldn’t be allowing that to happen — when people are projecting themselves in the air and if they don’t hit somebody in the head, they’re hitting them in the knee and everywhere else."

Some sports psychologists say the carnage is something our society — and perhaps even the NFL — craves, despite the serious risks for players. Some people satisfy a need when they sit on their couches Sundays and watch from a comfortable distance as men they have never met batter each other, psychologists say.

"It’s the same thing that happened analogously in the Roman Colosseum," Maher said. "People would go there and watch animals rip people to shreds. They enjoyed it. So there’s always that human tendency, and it’s not going away."

CONTACT SPORT

Football is built on contact at the line of scrimmage, where each play men line up face-to-face and attempt to overpower the other through sheer brawn. The mini-battles playing out, sometimes hidden across the scrimmage line, are won with technique, but also with pure strength and out-and-out aggression. The force of men — hard-packed with muscle, weighing upward of 300 pounds — careening into one another can be breathtaking, if not cringe-inducing.

Patriots coach Bill Belichick watches as Rob Gronkowski is treated for injury in the third quarter against the Cleveland Browns at Gillette Stadium in December.

Other players, with more normal body proportions, such as running backs and wide receivers, are human targets for tacklers, and the pounding can add up.

For instance, Seahawks running back Marshawn Lynch has carried the ball 1,753 times and caught 202 passes over his seven-year NFL career. Adding the same categories from college, plus returns, Lynch has been subjected to as many as 2,546 hits, not counting practices.

"Only the strong are going to survive," said former Giants defensive lineman Keith Hamilton, who had at least 17 surgeries over his NFL career. "That’s what you signed up for."

No amount of safety measures can stop the objective — to bring to the ground the player with the ball through force. But the NFL has tried to limit some dangerous plays by recently moving kickoffs up from the 35-yard line to the 40, and prohibiting both runners and tacklers from initiating contact with the crown of their helmet outside the tackle box.

Also, according to the NFL Physicians Society, on game days there is a total medical staff of 27 people on the field, including athletic trainers, orthopedists, a neuro-trauma consultant and an airway management physician.

"There are always going to be injuries with this sport," said Matthew Matava, president of the NFL Physicians Society and the head team physician for the St. Louis Rams. "No matter what we do, there will always be a risk for injuries. The players know that. The physicians know that. Only time will tell the real influence of some of the rules changes we’re making now."

A DISCONNECT

Chris Stankovich, a Columbus, Ohio, professional athletic counselor who has written about sports culture, says some fans have an innate craving for taking in the violence, often without regard for the health risks players face. It’s the same reason people love to watch action movies, play video games depicting war and see car wrecks in NASCAR, he said.

"We do tend to want to see the things that we haven’t seen before, and we depersonalize," Stankovich said. The players, he added, "don’t really register to us because we don’t have that connection to them."

In the locker room, some players relish in their toughness, Hamilton said. Inflicting pain and punishment — and coping with it yourself — are parts of the job.

"You get your tape, you get your medicine and you get whatever you have to do to get over the hump," Hamilton said. "That’s just the reality of the situation."

"You were playing with torn labrums and torn meniscus and different things. But you waited until after the season was over. Those were just the things you played through."

At this point, the bruising nature of the game seems to be accepted by players and fans.

President Obama, in a lengthy profile in a recent issue of the New Yorker, weighed in.

"At this point, there’s a little bit of caveat emptor," Obama said. "These guys, they know what they’re doing. They know what they’re buying into. It is no longer a secret. It’s sort of the feeling I have about smokers, you know?"

Meanwhile, the sport’s popularity continues to surge. The NFL has added a nationally televised game on Thursday nights and is showcased in yearly matchups in London. Football keeps churning, with many fans seemingly unfazed by the violence.

"There’s a limit to where we’re pushing it," said McInerney, from Saint Joseph’s Medical Center. "And we should recognize we’re at the limit now."

MORE SUPER BOWL COVERAGE

FOLLOW THE STAR-LEDGER: TWITTER • FACEBOOK • GOOGLE+