Slap fighting athletes face high risk of concussion

'Slap fighting' is far less well-known than boxing, as well as some other sports that involve regular impacts to the head. But slap fighting competitions, in which two people stand opposite each other and take it in turns to deliver open-handed strikes to their defenceless opponent's face, are now drawing millions of online viewers following their debut in 2023, write the authors of a research letter to JAMA Surgery.

According to their research, however, the activity is also dangerous, with participants at high risk of suffering concussion — injury to the brain. And, given the link between concussions in sport and ongoing or later neurological impairment, Raj Swaroop Lavadi at the University of Pittsburgh and colleagues are concerned.  

The team analysed videos of 333 slaps and 139 slap sequences — defined as a series of slaps against the same defender within a single match — from 78 fights involving 56 contestants. Four separate reviewers looked for visible signs of concussion in these contestants after they were slapped. Their list of signs included physical clumsiness, a blank and vacant look, a seizure, and vomiting.

Overall, more than half of the slap sequences resulted in contestants showing signs of concussion. Of the 56 contestants, 44 (almost 80%) had a visible sign of concussion at least once in their matches, and there were 20 instances of a contestant showing a sign of concussion after having shown at least one sign following a previous slap. (Current guidance for even grassroots sport stresses that anyone showing signs of a concussion should not be put back into play.)

The most common signs observed by the team were movement difficulties, being slow to get back up after being knocked down, and a blank and vacant look. "The findings of this…study suggest that slap fighting may induce traumatic brain injury in contestants, with potential for long term consequences," the team writes.

Concern about the long-term risks of repeated head injuries in other sports, such as rugby, are growing. A recent study in JAMA Neurology of nearly 2,000 former US National Football League players also found that 34% believed they have chronic traumatic encephalopathy (CTE), a neurological condition linked to repeated head trauma (though the percentage that actually suffer from CTE, which is diagnosed post-mortem, is unknown).

In relation to the new findings on slap fighting, Lavadi said, in a comment released to accompany the paper, "it is really difficult to ban any sport, but it is possible to raise awareness about the associated harms."

Read the paper in full:
Raj Swaroop Lavadi, Rohit Prem Kumar, Kann, M. R., Shah, M. J., D. Kojo Hamilton, Maroon, J. C., & Agarwal, N. (2024). Video Analysis of Concussion Among Slap Fighting Athletes. JAMA Surgery. https://doi.org/10.1001/jamasurg.2024.2605

Want the latest in psychological research, straight to your inbox?
Sign up to Research Digest's free weekly newsletter.