Millions have seen it. The snap, then a quarterback steps back searching over the heads of a jumble of 300-pound men. In seconds he finds his target and throws, the receiver reaches, he pulls the ball in, turns and — crunch — a serious tackle.
"Ooohs" echo through the stadium as millions cringe with sympathy for the player's pain. But moments later the receiver's up again, slapping his teammates' helmets and butts in celebration.
Football players get brief sympathy for their moments of agony, but the pain of contact sports can linger after the game, after the season, and sometimes what's called chronic pain for life.
Hard collisions can cause permanent nerve damage. And daily pounding can give young men the tendons, ligaments and arthritic joints of old age.
"When you decide to play football, unless you don't have any feeling in your body, you'll just have pain," said Lyle Blackwood, 56, who played in two Super Bowls during his 14-year career as a safety in the NFL. "It's part of the job description."
Blackwood has cracked his ribs 10 times. He broke his nose during a game and returned after an injection of xylocaine to play in the second half. He's suffered more than 10 knockout concussions. Still, Blackwood says he's better off than some. "I'm still out walking around, moving."
Chris Dieterich, 49, is less fortunate. At 6 feet 3 inches and 300 pounds, Dieterich played as an offensive lineman for the Detroit Lions in the early 1980s.
"My joints start to feel like they have glass in them, ground up glass when I move," says Dieterich, who suffers from osteoarthritis. "I haven't run since I was 30, but I can walk."
Retired pro-football players are two-thirds more likely than other men to have arthritis in their 50s, according to statistics from the U.S. Centers of Disease Control and Prevention and the Center for the Study of Retired Athletes.
On a good day, Dieterich says he feels shooting pain in his knees, shoulders and back only about a dozen times. He had two hip replacements by age 46, and he's scheduled for another this year.
As if that's not bad enough, Dieterich suffers from nerve damage. At 40, Dieterich was diagnosed with degenerative disk disease, a condition where small vertebrae in your back that act like shock absorbers for the spine eventually tear and rupture, irritating nearby nerves.
"Basically, I have the spine of an 80-year-old man," said Dieterich, who is forbidden by doctors' orders to lift anything — even his luggage at the airport.
Dieterich's chronic pain only becomes "tolerable" with daily stretches or pool exercises.
"It's not worth it looking back, but being 22 years old — no amount of argument could have kept me off the field," said Dieterich.
Chronic pain can strike athletes in two ways, says David Ruch, orthopedic surgeon at Duke University.
There's the years of wear and tear on joints, ligaments and tendons that hurt in middle age. Then there's damage that modern medicine still cannot fix.
Ruch once treated a woman basketball player with a bad wrist injury. Ruch could reconstruct her ligaments to ease the pain, but her hand wouldn't be flexible enough to play in the WNBA.
Ruch says the athlete instead asked Ruch to do a procedure to let her play, although it meant she would be in chronic pain by middle age.