The King-Devick test in mixed martial arts: the immediate consequences of knock-outs, technical knock-outs, and chokes on brain functions

Ryan Hubbard, Gene Stringer, Ken Peterson, Mario Roberto Filho Vaz Carneiro, Jonathan T. Finnoff, Rodolfo Savica

Research output: Contribution to journalArticle


The aim of this prospective cohort study was to determine the effect of an ‘event,’ defined as a knock-out (KO), technical knock-out (TKO), choke, or submission, on King-Devick (K-D) test times in mixed martial arts (MMA) athletes. MMA athletes (28.3 ± 6.6 years, n = 92) underwent K-D testing prior to and following a workout or match. Comparison of baseline and post-workout/match K-D times to assess any significant change. K-D tests worsened (longer) in a majority of athletes following an ‘event’ (N = 21) (49.6 ± 7.8 s vs 46.6 ± 7.8 s, p = 0.0156, Wilcoxon signed-rank test). K-D tests improved (shorter) following a standard workout or match in which no ‘event’ occurred in a majority of cases (n = 69) (44.2 ± 7.2 s vs 49.2 ± 10.9 s, p = <0.0001, Wilcoxon signed-rank test). Longer duration (worsening) of post-match K-D tests occurred in most athletes sustaining an ‘event’; K-D tests shortened (improved) in a majority of athletes not sustaining an ‘event’. Our study suggests MMA athletes suffering an ‘event’ may have sustained a brain injury similar to a concussion.

Original languageEnglish (US)
Pages (from-to)349-354
Number of pages6
JournalBrain Injury
Issue number3
StatePublished - Feb 23 2019



  • brain injury
  • Concussion
  • King-Devick
  • mixed martial arts

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Developmental and Educational Psychology
  • Clinical Neurology

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