A sideline concussion test is a structured evaluation performed on or near the field of play after an athlete takes a hit to the head or body. Its purpose is to quickly determine whether the athlete has signs of a concussion and should be removed from the game. The testing covers three core areas: symptoms the athlete is experiencing, cognitive function like memory and concentration, and physical signs like balance and eye movement. Results are compared against baseline scores taken before the season to detect meaningful changes.
How Sideline Testing Works
The process actually starts before anyone gets hurt. During the preseason, each athlete completes a battery of tests while healthy. These baseline scores capture that individual’s normal performance on memory tasks, balance exercises, and symptom reporting. Because everyone’s brain works a little differently, having a personal baseline gives medical staff an objective reference point rather than relying on population averages.
When an athlete takes a suspicious hit during competition, the medical team pulls them aside and runs the same tests. They’re looking for measurable drops in performance. A decrease of even one point on cognitive screening or an increase of three or more errors on balance testing is considered clinically significant. Those numbers, combined with a physical examination, help the clinician decide whether the athlete has sustained a concussion. If there’s any indication of injury, the athlete stays out for the rest of the day and cannot return until cleared by a healthcare provider.
The SCAT6: The Standard Tool
The most widely used sideline assessment is the Sport Concussion Assessment Tool, now in its sixth version (SCAT6). It’s a multi-step evaluation that moves from urgent safety checks to more detailed cognitive and physical testing. Among all available concussion screening methods, the SCAT has the highest diagnostic accuracy, outperforming computerized neurocognitive tests, clinical observation alone, and eye-movement screens in head-to-head comparisons.
The SCAT6 begins with an immediate on-field screen that includes checking for observable signs like loss of consciousness or a blank stare, assessing the cervical spine for neck injury, testing coordination and eye movements, and asking memory questions (called Maddocks questions) such as “What venue are we at today?” or “Which half is it now?”
If there’s any concern, the athlete moves to a more thorough off-field assessment with several components:
- Symptom checklist: The athlete rates 22 possible symptoms, including headache, dizziness, blurred vision, feeling “in a fog,” difficulty concentrating, sensitivity to light and noise, and trouble falling asleep. Each symptom is rated on a severity scale, producing a total score out of 132.
- Cognitive screening: Tests of orientation (knowing the date, month, day of the week), immediate memory (recalling word lists), and concentration (reciting digits backward or months in reverse order).
- Balance examination: A modified version of the Balance Error Scoring System where the athlete holds three stances with eyes closed: feet together, one foot, and heel-to-toe (tandem). Errors like opening the eyes, stumbling, or lifting hands off the hips are counted. A timed tandem gait, basically walking heel-to-toe along a line, is also included.
- Delayed recall: About 10 to 15 minutes after the initial memory test, the athlete is asked to recall the same word lists. This tests whether short-term memory is functioning normally.
Eye Movement and Vestibular Tests
Concussions frequently disrupt how the eyes move and how the brain processes motion, so several sideline tools focus specifically on these systems. The Vestibular/Ocular Motor Screening (VOMS) assessment checks five areas: smooth pursuit (tracking a moving object), saccades (rapidly shifting gaze between two points horizontally and vertically), convergence (focusing on an object moving toward the nose), the vestibular ocular reflex (keeping vision stable while turning the head), and visual motion sensitivity (tolerance of busy visual environments). After each task, the athlete rates any changes in headache, dizziness, nausea, and fogginess on a 0-to-10 scale. A spike in symptoms during any of these tasks points toward concussion-related dysfunction.
The King-Devick test takes a different approach. The athlete reads single-digit numbers aloud from three test cards as quickly as possible without errors. It captures problems with rapid eye movements, attention, and language processing, all functions that suffer when the brain isn’t working normally. A worsening of five seconds or more compared to baseline is a red flag strongly associated with head trauma and is sometimes used as a threshold for pulling an athlete from play.
Why Sideline Tests Are Imperfect
No sideline test is a concussion detector with perfect accuracy. The pooled sensitivity of available screening tools ranges from about 50% to 88%, meaning some concussions will be missed, particularly mild ones. Specificity sits around 80% to 85%, so most non-concussed athletes will correctly test as fine.
The sideline environment itself creates challenges. Physical exertion, adrenaline, crowd noise, and the intensity of competition can all produce symptoms that overlap with concussion, like headache, fatigue, and difficulty concentrating. Medical staff have acknowledged difficulty distinguishing between mild cognitive deficits from a concussion and the normal effects of playing a hard game. This overlap is one reason the tests emphasize comparison to individual baselines rather than relying solely on a single post-injury score.
Athletes also underreport symptoms. Some don’t want to leave the game. Some genuinely don’t realize something is wrong. This is particularly concerning with younger athletes, where self-reporting is less reliable and parents, coaches, and medical staff need to lean more heavily on objective testing tools rather than taking the athlete’s word for how they feel. A child-specific version of the SCAT6 exists for athletes under 13, with age-appropriate modifications to the cognitive and symptom sections.
What Happens After You Fail a Sideline Test
If any component of the sideline evaluation raises concern, the athlete is removed from play immediately. There is no “wait and see” on the same day. The CDC’s guidance is clear: the athlete stays out for the remainder of that game or practice and cannot return until evaluated and cleared by a healthcare provider. Coaches and trainers are not qualified to judge the severity of a concussion on their own.
The sideline test is a screening tool, not a final diagnosis. It tells medical staff whether a concussion is likely, but a full clinical evaluation follows. That typically involves more detailed neurocognitive testing, symptom monitoring over subsequent days, and sometimes imaging to rule out more serious injuries like bleeding in the brain. The sideline assessment is the first gate, designed to catch injuries early and keep athletes from returning to play while their brain is still vulnerable to a second impact.