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It is now known that visual, oculomotor, and visual Harpham et al. found a significant association between
psychomotor skills important to performance tasks are visual skills scores and reaction time scores with both
affected by previous concussion. 23,28,42,81,82 It is entirely linear and rotational helmet-impact severity in college
plausible that many SOF are visually and/or cognitively football players. Lower performers on the sensory sta-
impaired without realizing it, or they are underreport- tion sustained significantly more severe head impacts, as
ing symptoms. Neurocognitive baseline assessment measured by the Head Impact Telemetry (HIT) System
is recommended for suspected concussion in military (Simbex; www.simbex.com). In two players who received
practice settings, and is mandatory for all SOF. Recom- concussion during that season, sensory station scores re-
mendations have been based on evidence from sports mained below baseline for a significantly longer period of
concussion literature, though findings are difficult to in- time than did computer-based neurocognitive scores as
terpret, as there are no normative data for Servicemem- measured by the Automated Neuropsychological Assess-
bers, especially those in a deployed setting, and there ment Metrics (Vista Life Sciences; www.vistalifeciences.
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are many factors that can confound neurocognitive per- com). The number of concussed individuals is too low
formance. 2,12,17,37,41,70,83–88 Despite the wealth of literature to make any claims, but the differences noted were clini-
supporting use in athletic populations, there is currently cally meaningful enough to warrant further studies using
no impetus for comprehensive visual-skill baseline as- the Nike STS.
sessments or performance training for military person-
nel who have suffered mTBI, due to a paucity of military Erickson et al. found the Nike STS could produce re-
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studies on the subject. peatable and reliable evaluation results for visual skills
screening with some mild learning effect noted only in
Visual skills performance evaluations and visual skills the eye–hand coordination and go/no-go assessments.
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training programs attempt to assess and enhance pro- Referrals to eye specialists can be made based on lower
cessing of visual information by optimizing coordination performance scores, making it an excellent visual screen-
among sensory processes, visual attention, and motor ing tool. Visual performance training should be initiated
outputs. These psychomotor abilities are predictive of based on the scores the station provides for each do-
better performance in a wide variety of tasks. Therefore, main assessed. It also provides normative data for many
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comprehensive visual screening, as part of Special Forces sports populations. The stations within the US Army
Human Performance Programs and Special Forces Duty Special Operations Command (USASOC) have been
Performance participation, should take place. Vision is preprogrammed for data collection on SOF qualified
a critical factor in sports performance and visual infor- and support personnel.
mation is a dominant sensory system when performing
practically any perceptual motor task such as those en- Since the Nike SST evaluates a wide variety of visual
countered in sports. 32,54,58,60,63,64,72,77,78,89–92 Therefore, the skills at the single station instead of using many differ-
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evaluation of vision skills in athletes is an area of intense ent and expensive apparatus, advantages are cost sav-
interest. Since vision is so critical, it is surprising that ings and the need for less space. All the available tests
many athletes and Soldiers have never received a com- on the station are recommended by the American Op-
prehensive vision examination and are largely unaware tometric Association Sports Vision Section in the visual
of the potential impact of sports vision services on perfor- evaluation of athletes, though the STS does not include
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mance. Reaction time is visually mediated. 58,63,64,68,70,72,78 the ability to evaluate all of the recommended skills and
Therefore, a more in-depth look at vision and visual skills functions. Functions for which the station is unable to
associated with reaction time and sport performance, as collect quantitative data for are: dynamic visual acuity,
well as influencing factors, is warranted. refractive status, ocular alignment, eye–body coordina-
tion, visual coincidence anticipation, vision and balance,
In a recent Defense Advanced Research Projects Agency peripheral awareness, visualization and imagery, or ocu-
(DARPA) funded study, the measures of the STS were lar health status. Refractive status, ocular alignment,
found to be valid and informative tools for assessing and ocular health status require evaluation by a board-
visual performance that can be used to measure cross- certified optometrist or ophthalmologist. Dynamic visual
sectional and longitudinal differences. After reduction acuity, eye–body coordination, visual coincidence antici-
analysis of the 10 tasks evaluated by the STS, three pation, vision and balance, peripheral awareness can all
latent contexts were identified: visual-motor control, be trained using a sensory station, but not quantified.
visual sensitivity, and eye quickness. The effects of circa-
dian rhythms, alcohol, and caffeine intake on cognition Visual Skills Training for
were analyzed. Interindividual variability was primar- Human Performance in Special Operations
ily observed for the visual-motor control component. A
significant but lesser amount of variability was noted in Many factors influence sport performance: biomechani-
the eye-quickness domain as well. 70 cal factors, strength and conditioning, visual factors, and

58 Journal of Special Operations Medicine Volume 15, Edition 2/Summer 2015