Aim: To determine whether the King-Devick (K-D) test used as a sideline test in junior rugby league players over 12 matches in a domestic competition season could identify witnessed and incidentally identified episodes of concussion.

Methods: A prospective observational cohort study of a club level junior rugby league team (n=19) during the 2014 New Zealand competition season involved every player completing two pre-competition season baseline trials of the K-D test. Players removed from match participation, or who reported any signs or symptoms of concussion were assessed on the sideline with the K-D test and referred for further medical assessment. Players with a pre- to post-match K-D test difference >3 s were referred for physician evaluation.

Results: The baseline test-retest reliability of the K-D test was high (rs=0.86; p<0.0001). Seven concussions were medically identified in six players who recorded pre to post-match K-D test times greater than 3 s (mean change of 7.4 s). Post-season testing of players demonstrated improvement of K-D time scores consistent with learning effects of using the K-D test (67.7 s vs 62.2 s).

Discussion: Although no witnessed concussions occurred during rugby play, six players recorded pre to post-match changes with a mean delay of 4 s resulting in seven concussions being subsequently confirmed post-match by health practitioners. All players were medically managed for a return to sports participation.

Conclusion: The K-D test was quickly and easily administered making it a practical sideline tool as part of the continuum of concussion assessment tools for junior rugby league players.

Summary Points:

  • Evaluated the K-D test for screening concussion in youth rugby players ages 9-10.
  • Routine post-match screening with K-D test identified 7 unwitnessed, unreported concussions that were later diagnosed by a physician.
  • The K-D test demonstrated high test-retest reliability at baseline in this cohort of junior rugby players.

The K-D test is an effective tool to determine if a player should be removed from play and referred to a physician for further evaluation.

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