The aim of this prospective cohort study was to determine the effect of an ‘event,’ defined as a knockout (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 postmatch 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.

Summary Points:

  • The sensitivity of the K-D was 87% for detecting athletes with probable brain injury (defined as a witnessed KO or TKO with a subsequent slowed K-D test).
  • This study confirms that following a KD or TKO in MMA, in a majority of athletes, the K-D time is slower than baseline and, occasionally, the fighters also make errors on testing.
  • This study also demonstrated slowed K-D times in a majority of athletes who sustained “events” such as chokes, near chokes, or submission holds. These findings suggest that these “events” may also impair brain function and represent a concussive event.
Read More