Seemingly harmless gesture a warning sign of a concussion in athletes

A common, seemingly innocuous gesture could be a sign of a concussion, and experts say recognizing it could be the key to reducing the number of concussions that go undiagnosed. It’s the quick head shake after a hard hit.

That movement, called the Spontaneous Headshake After a Kinematic Event, aptly shortened to SHAAKE, can be seen among athletes across various sports time and time again, but it’s long gone mostly overlooked as a symptom of concussion.

To better understand the movement, researchers with Mass General Brigham and the Concussion Legacy Foundation surveyed hundreds of high school, college and semi-pro athletes. They found most of the athletes were familiar with the action and have even experienced it themselves, often more than once.

In nearly 3 out of 4 cases, researchers found those who experienced SHAAKE got a concussion at that time. They also found the causes of SHAAKE are often common symptoms of concussion, like disorientation, confusion and changes to spatial perception. However, the head shake by itself is not considered a sign of concussion, leading many brain injuries to go undiagnosed.

The researchers behind the new study now say formal recognition of SHAAKE as a sign of a concussion could help identify up to a third of undiagnosed concussions.

In the study, the researchers pointed out a particularly nasty concussion seen in 2022 involving Miami Dolphins quarterback Tua Tagovailoa. They say the example highlights how adding SHAAKE to professional concussion protocol could make a big difference.

Tagovailoa fell to the ground after a hard hit. It was attributed to a previous back injury at first, but he later ended up being hospitalized with a concussion. The study’s authors said hospitalization may have been avoided if SHAAKE were part of the protocol.

Many people called for Tagovailoa to retire after that injury, but he refused. Those calls were renewed when he suffered his third career concussion during the Dolphins’ game against the Buffalo Bills in September.

In a press conference Tuesday, Oct. 22, the Dolphins announced Tagovailoa would be back at practice Wednesday, Oct. 23, with hopes of playing in the game against the Arizona Cardinals on Sunday, Oct. 27. Tagovailoa also said he would not wear a Guardian Cap, which is a protective helmet cover used as an extra layer of defense against concussions.

There are actually multiple helmet options that players can pick from that test just as effectively as wearing the guardian cap.

I'd be interested to know if he made a helmet switch instead https://t.co/PGwgq3Lnlj

— Jamal St. Cyr (@JStCyrTV) October 21, 2024

While SHAAKE was not added in the wake of the quarterback’s 2022 injury, the NFL did update the league’s concussion protocol.

In a statement in response to this new study, the NFL’s chief medical officer said the league regularly reviews new research, adding, “Our concussion protocol, a conservative process developed from internationally accepted guidelines, is reviewed annually to ensure players are receiving care that reflects the most up-to-date medical consensus on the identification, diagnosis, and treatment of concussions.”