Concussions in American football

Concussions and play-related head blows in American football have been shown to be the cause of chronic traumatic encephalopathy (CTE), which has led to player deaths and other debilitating symptoms after retirement, including memory loss, depression, anxiety, headaches, stress, and sleep disturbances.^[1]

The list of ex-NFL players that have either been diagnosed post-mortem with CTE or have reported symptoms of CTE continues to grow.^[2][3] According to Boston University, CTE is a brain degenerative disease found in athletes, military veterans, and others with history of repetitive brain trauma. Although CTE is highly controversial and misunderstood, it is believed that a protein called Tau forms clumps that slowly spread throughout the brain, killing brain cells.

There is also theoretical research that suggests early CTE might result from damaged blood vessels within the brain. That could trigger brain inflammation and, eventually, the development of proteins such as Tau believed to play a key role in CTE. This hypothesis was tested on adult mice; the researchers state that their brains possess similar attributes to that of human brains. Using a special device, the mice were given precise impacts that would lead to mild brain traumas similar to what an athlete would suffer in contact sports. The mice, whose brains were scanned using a specialized MRI, immediately showed changes to the electrical functions of their brains.^[4]

According to 2017 study on brains of deceased gridiron football players, 99% of tested brains of NFL players, 88% of CFL players, 64% of semi-professional players, 91% of college football players, and 21% of high school football players had various stages of CTE.^[5]

Other common injuries include, injuries of legs, arms, neck and lower back.^[6][7][8][9]