The fencing position, which is when a person’s arms are raised while bent and stiffened, is a sign that something happened to the brain stem, according to Healthline. People usually stay like that for a few seconds, and then it goes away. However, even though it usually disappears quickly, it is not something that should be ignored, as brain injuries are not something to be trivialized. The fencing response can also aid in diagnosis as well, as it can even be a greater sign that a brain injury has happened than medical imaging, which doesn’t always pick up concussions or other brain traumas. 

Football is far from the only sport that one can see this result. Watch an MMA match and chances are you’ll see a downed fighter adopt that pose after being knocked out. Boxers also run the same risk, as do non-athletes after what may seem like a simple punch to the head in a backyard brawl — basically anything that involves possible trauma to the brain.

While changes and improvements are being made with equipment, the big issue is that the inherent nature of brain injuries makes it difficult, if not impossible, to completely safeguard athletes, short of completely banning sports altogether. Unfortunately, when someone has repeat brain injuries, it can cause long-term damage to the brain and can even cause behavioral changes, and sometimes this can have tragic results — former NFL players like Junior Seau, Dave Duerson, and Vincent Jackson were just some of the ones who doctors determined (after their deaths) to have had CTE, or chronic traumatic encephalopathy (via Boston University CTE Center).