San Francisco 49ers player Trenton Cannon was taken off the field in an ambulance during Sunday's game against the Seattle Seahawks.
Shortly after the game's opening kickoff, the 27-year-old running back crashed into 49ers safety Talanoa Hufanga as they both tried to take down Seattle's DeeJay Dallas. Hufanga's left thigh collided with Cannon's head, forcing his neck to bend backwards, ESPN reports.
Cannon was seen moving his left arm after being loaded onto a stretcher by medical personnel and was diagnosed with a concussion.
Prayers up for Trenton Cannon. He stayed down after this play on the opening kickoff. The ambulance & stretcher is out for him. 🙏 pic.twitter.com/109ZvFjZJa
— ✯✯✯✯✯ (@FTB_Vids_YT) December 5, 2021
During a postgame press conference, 49ers head coach Kyle Shanahan told reporters, "Concussions are very concerning, but all the stuff that you're really worried about — he's cleared."
He added that Cannon "remembers it all" and will be kept overnight at the hospital for further evaluation and monitoring.
As defined by the Centers for Disease Control, concussions are traumatic injuries generated by hits to the head or body that cause the brain to bounce around the skull. Football players, of course, may experience many throughout their careers.
According to Mayo Clinic, repeated concussions can lead to chronic traumatic encephalopathy, also known as CTE, which is characterized by long-term effects such as trouble concentrating, memory problems and depression.
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In July, former NFL quarterback Jay Cutler told GQ he may have suffered multiple concussions before his retirement from professional football in 2017.
When asked whether he was concerned about potentially developing CTE (the condition can only be diagnosed with a brain examination after death), Cutler said he may already recognize signs of the disease in himself.
"Oh, absolutely," he said. "I would say definitely my memory isn't the same as it was 5 years ago. The amount of concussions I've had are probably in the double digits."
"It's gonna catch up to me at some point," Cutler added. "I'm just trying to delay it as much as possible."
While not all football players develop CTE, it is widespread. A 2017 study of the brains of 111 deceased NFL players by a Boston University researcher found 110 of them had the disease.