Damar Hamlin's collapse put a spotlight on football injuries — here are the worst accidents to strike the NFL

• Damar Hamlin's collapse was a reminder that football can be a dangerous sport.
• In spite of efforts to reduce the risks, injuries and concussions are common among NFL players.

Damar Hamlin's collapse is the latest in a series of high-profile injuries highlighting the risks that come with playing football at the top level.

Here are some of the most notable injuries to rock the NFL that remind players of the risks that remain despite efforts to make the game safer.

Johnny Knox, December 2011, fractured vertebrae

Johnny Knox of the Chicago Bears suffered a career-ending injury in 2011 when a tackle bent his back the wrong way, leading to multiple vertebrae fractures.

Orthopedic injuries — accidents affecting the limbs — are the most common type of injuries in football, per the NFL physicians association.

Tua Tagovailoa, September 2022, possible repeat concussion

The Miami Dolphin's Tua Tagovailoa's high-profile concussion reopened a conversation about the risk for young players.

In spite of efforts made to reduce head injuries, notably after a groundbreaking hundred-million dollar settlement with former players, concussion is still a very real risk faced by NFL players.

In the preseason and regular season in 2022, 187 concussions were reported, per the NFL website.

Tagovailoa passed out after hitting his head on the turf after a tackle in September. He self-reported temporary memory loss.

He had another violent knock to the head just four days earlier, which may have led to another undiagnosed concussion, an expert told Insider at the time.

If he had another head injury during the ongoing season, it could be career-ending, the expert said.

Rashad Johnson, September 2013, severed finger

One of the most shocking examples of injury to limbs took place in 2013, when Arizona Cardinals' safety Rashad Johnson removed his glove after a tackle, only to find the tip of his middle finger had snapped off.

His finger had to be shaved down to the first knuckle.

Damar Hamlin, January 2023, cardiac arrest

It is not clear what caused the Buffalo Bills player's cardiac arrest during a game on Monday, January 2.

But it is possible that the tackle from Tee Higgins of the Cincinnati Bengals triggered his condition, despite not immediately seeming exceptionally violent.

Experts say that a hard blow to the chest could trigger an undiagnosed heart issue. It's also possible the tackle could have caused Commotio cordis, when a blow happens to hit at a very specific time in the heartbeat cycle and causes it to stop.

The NFL's only in-game death: Chuck Hughes, October 1971, heart attack

Hamlin isn't the only player to have collapsed on the field with a heart issue. In 1971, Detroit Lions player Chuck Hughes had a fatal heart attack.

Hughes died of undiagnosed atherosclerotic coronary heart disease — a thickening and clogging of the arteries. He's the only player to die during an NFL game.

Though there are not many examples of cardiac issues on the pitch, a 2019 study found that retired players may face an increased risk of having an irregular heartbeat called atrial fibrillation, which can lead to stroke, though more research would be necessary to confirm this trend.

Safeguarding efforts are underway

The NFL says it has been working hard to reduce the risk to players. Measures include improving the protective quality of the padding, deploying extensive medical teams at stadiums, and new game rules aimed at reducing risk.

In 2018 for instance, the league introduced a rule prohibiting players from ramming opponents head-on with their helmets, The New York Times reported.

The NFL is also discussing the rollout of Guardian Caps, a protective layer worn around the helmet designed to reduce concussive blows. These could reduce the risk of concussion for players by 10 to 20%, and were tested in this year's preseason.

In spite of these efforts, it's not clear how much more can be done to protect players, former NFL player Donté Stallworth told CNN while talking about Hamlin's condition.

"I don't know if you can make the game any much safer," he said. "This is a brutal sport. I think people forget that."