King-Devick test for sideline concussion screening in collegiate football

Leong DF, Balcer LJ, Galetta SL, Evans G, Gimre M, Watt D. Journal of Optometry. 2015. doi:
10.1016/j.optom.2014.12.005. [Epub]

Take Home Message: The King-Devick test is a
quick and reliable method to assess vision, eye movements, language function,
and attention. An athlete with a concussion tends to complete the test slower
than his/her preseason assessment while other athletes improve over time. 

With recent attention on the potential consequences
associated with concussions there has been an emphasis on rapid and accurate
diagnosis of concussions.  This will aid in removal from activity to
assist recovery and hopefully prevent athletes from sustaining further head
trauma.  The purpose of this article was
to assess the validity of the King-Devick test as a sideline concussion
assessment among collegiate athletes. 127 student-athletes (football, men’s and
women’s basketball) with a mean age of ~20 years participated in this study.  Participants completed a baseline King-Devick
test during preseason physicals.  The
test takes two minutes and requires an athlete to quickly read a series of
numbers on three test cards. If an athlete sustained a concussion then he/she completed
the King-Devick test and Sport Concussion Assessment Tool 2 (SCAT-2)
immediately on the sideline. Non-concussed participants completed post-season
testing to compare to the baseline results in order to assess performance
changes and reliability over the season. 
Basketball players also completed the test immediately after an intense
sprint workout to see how the test was affected by exercise. During the course
of the season 11 athletes sustained a concussion and 9 failed their sideline
SCAT-2 test. The authors found that individuals who suffered a concussion took longer
to complete the King-Devick test compared with their baseline measurements.  On average concussed participants took 4.4 seconds
longer compared with their baseline times. 
In contrast, participants without a concussion were slightly faster
during post-season testing, which may indicate a learning effect. The test had excellent
retest reliability from baseline to post-season in non-concussed participants.  The post-workout results were similar to the
post-season results, which indicated that fatigue did not influence the test

The King-Devick test appears to be a valid and reliable assessment
for concussions among college athletes.  The
King-Devick tests’ portability and simplistic approach makes it an ideal
sideline assessment for detecting changes in quick eye movements and saccades
observed in individuals suffering from head trauma. Although the King-Devick
test seems to be an effective method to assess concussions, it is not clear yet
if it can serve as a standalone evaluation. 
Multiple measures may be ideal to gain a complete picture of an
individual athlete’s symptoms and deficits. 
Considering there are limited studies on the King-Devick test, more
research needs to be completed to assess its’ effectiveness to assist
clinicians for rehabilitation purposes and return-to-play decisions. It is
important to note that this study had a small number of athletes with
concussions, which limits our ability to apply these results to other
collegiate athletes and limited the authors’ ability to suggest clinically
relevant cut-points that may differentiate athletes with or without a
concussion.  Despite these limitations, this
is another tool sports medicine professionals may use on the sidelines to
assist in the rapid detection of concussions.

Questions for Discussion: What sideline
assessments do you use for concussions? Which do you think are the most
effective? Have you tried using the King-Devick test?

by: Adam Rosen and Andrew Sheridan
by: Jeffrey Driban


Leong, D., Balcer, L., Galetta, S., Evans, G., Gimre, M., & Watt, D. (2015). The King–Devick test for sideline concussion screening in collegiate football Journal of Optometry DOI: 10.1016/j.optom.2014.12.005