When Chicago plays Indianapolis on Sunday next there will be several Super Bowl games going on at the same time. One game will be on radio, one on television, one in the stadium, one on the sidelines, and one on the field. For civilians, standing on the sidelines is as close as we're ever going get to an NFL game.

Stand on stadium grass and you'll see a football game that is an order of magnitude faster then any football game you've ever witnessed. Every player moves fast -- the 330-pound tackle moves fast, the 250 running back is a blur. The sounds of pads popping, the grunts, the crash of a 250-pound world-class athlete running into a 330-pound world-class athlete at full speed. Muscles are torn from bones, tendons rupture, bones shatter, ribs, fingers, legs, and ankles snap.

From this close distance, the game is incredibly violent -- unbelievably violent, actually. It's another kind of game, entirely, than the one you see on TV. The first time I saw a play from this perspective, it was an end-around run. I thought, "Amazing, that this is legal."

Merrill Hoge, a Pittsburgh Steelers running back, told the Pittsburgh Tribune-Review, "You want to know how hard you're hit? If you're a running back, and you're hit full-speed, he can literally knock the feces out of your bowels. You lose all feeling in your limbs. That's how hard they hit in the NFL."

A while back, I wrote a "Where are they now?" story about the Chargers. I contacted players from every decade, starting with Jack Kemp, the 1960 quarterback of the Los Angeles Chargers. I talked to Lance Alworth, Chargers wide receiver (1962--1972) and Hall of Fame inductee. There were 30 interviews in all; 11 made it into the story. What remains sharp in my memory is that everyone I talked to had been injured. Most of the men were in their 40s or 50s and they were all physically damaged, many with injuries that will never be healed: bad knees, bad spines, bad necks. Lots of replacement hips, replacement knees, titanium rods in spines, screws in bones. Everybody, it seemed, had arthritis.

I saw an item in today's paper about Peyton Manning's injured right thumb. They say it's not a problem, but the piece brought a question to mind: "How bad is it?" Not Manning, but injuries in the NFL. Follows are some NFL injury facts, most of them taken from a 2005 Tribune-Review series.

More than half of NFL players are injured every year; 68 percent were injured during the 2003 season.

Defensive players are injured more often than offensive players. Two thirds of all safeties are injured every year and "half of those will sustain a second injury unrelated to the first. On average, seven pro football players a week face potentially life-altering head, spine, or neck trauma."

Forty percent of quarterbacks are injured every year, half the linebackers, more than half the wideouts and tight ends. According to the federal Department of Labor, the NFL injury rate is eight times higher than NASCAR, NHL, NBA, or any other professional sports league.

Fifty-five percent of 1960s NFL players "suffered career-ending injuries or required multiple surgeries to correct the trauma of the game. For the players in the 1970s and 1980s, however, that trend rose 25 percent..."

Knee injuries account for a bit more than 15 percent of all injuries. Forty percent of former NFL players develop arthritis.

Some positions are considerably more dangerous than others, "Nearly 7 out of 10 cornerbacks face serious injuries annually, partly because of the sheer force they must generate to bring down big, fast running backs and receivers." According to the NFL, at the start of the 2006 season, 354 players weighed over 300 pounds.

Remember Joe Montana? He's 50 now. He's had a dozen surgeries and a half dozen brain concussions. His right eye has nerve damage, his neck is so damaged that if he needs to turn to talk to someone over there, he turns his torso rather than his neck. He had spinal fusion surgery two years ago and needs knee-replacement surgery. Joe says what every player I interviewed told me: he'd do it again. I don't know how much of that is the difficulty of saying, at the age of 50, when there's no going back, "I crippled myself. I was a fool," and how much is a warrior's love of combat and fellowship.

The first college football game occurred on November 6, 1869. Rutgers beat Princeton 6-4. The forerunner of what would become the NFL wasn't formed until 1920. Until then football was a college game except for some city athletic clubs who paid some of their players. The 1905 collegiate football season ended with 18 deaths. In 1909, the death toll was 33.

Things are getting better.