Observable signs of concussion in professional slap fighting using established video review protocols for professional sports: frequency, predictors, and implications for public concussion recognition awareness.

INTRODUCTION: Concussion is a traumatic brain injury (TBI) with potential short- and long-term neurological consequences. Recognition of objective concussion signs remains limited. In slap fighting, a combat event involving the exchange of defenseless head contact, concussion signs are visible. The study objective was to examine the frequency of observable signs of concussion among professional slap fighters based on established video review protocols and determine whether participant characteristics predict concussion signs. METHODS: Three independent reviewers evaluated publicly available video of professional slap fighting events (Power Slap™; 2023-2024) against the National Football League Concussion Protocol, the World Rugby Head Injury Assessment, and International Consensus Guidelines for observable signs of concussion. Signs were recorded for each strike and aggregated across rounds, matches, events, and combatants. Mixed effects logistic regression evaluated associations among pre-slap characteristics and the likelihood of observing a sign of concussion following a strike. RESULTS: Combatants (60 male, three female) competed across 62 matches in six Power Slap™ events. Of the 61 combatants who received a strike, 46 exhibited at least one sign of concussion. Overall, 29% (82/280) of strikes resulted in at least one observable sign of concussion, with lower, identical results across protocol guidelines (24%; 66/280). Signs of concussion were observed in 90% (56/62) of matches. Motor incoordination (23%; 64/280), blank/vacant look (15%; 41/280), and slow to get up (14%; 40/280) were the most frequently observed signs. CONCLUSION: Observable signs of concussion from professional slap fighting occurred in one-third of strikes and the majority of matches.