Objectives
Sport-related concussion (SRC) research has focused on impaired oculomotor function. The King–Devick (K–D) test measures oculomotor performance and is reported to identify suboptimal brain function. The use of the K–D test in Australian football (AF), a sport involving body contact and tackling, has not been documented. Therefore, the objective of this study was to determine the test–retest reliability and diagnostic accuracy of the K–D test on a sub-elite AF team.
Design
Prospective cohort study.
Methods
In total, 22 male players (19.6 + 2.3 years) were tested and re-tested on the K–D test. Those suspected of having a SRC secondary to a significant head impact were tested. Randomly selected additional players without SRC were assessed for comparison.
Results
There were observable learning effects between the first and second baseline testing (48 vs. 46 s). The ICC for the first and second baseline tests was 0.91. Post-match test times were longer than the baseline times for players with SRC (n = 7) (−1.9 s; z = −5.08; p < 0.0001). Players tested with no signs of SRC (n = 13) had an improvement in time when compared with their baseline score (3.0 s; z = −4.38; p < 0.0001). The overall sensitivity was 0.98, specificity 0.96, and a kappa of κ = 0.94. The positive likelihood ratio was 11.6 and the positive predictive value was 89.0%.
Conclusions
This study supports the use of the K–D test due to its test–retest reliability, high sensitivity and specificity, and fast and simple use that is ideal for sports medicine professionals to make quick judgement on management and playability.
Summary Points
- There was a 2 sec improvement between the 1st and 2nd K-D Test trials, with excellent test-retest reliability for this Australian football team.
- Players with a sport-related concussion scored significantly worse than baseline. Players without concussion scored significantly faster than baseline.
- There was a high sensitivity (98%) and specificity (96%) of the K-D Test in identifying a concussed player.
- The K-D Test involves integration of functions of the brainstem, cerebellum, and cerebral cortex via visual processes and an athlete’s change in score is suggestive that a meaningful neurological event has occurred.
- This study supports the use of the K-D test due to its test-retest reliability, high sensitivity and specificity, and fast and simple use that is ideal for sports medicine professionals to make quick judgement on management and playability.