Baseline concussion testing is a pre-injury evaluation designed to measure an individual’s normal, healthy brain function. This assessment provides a personal blueprint of cognitive and physical abilities, such as memory, reaction time, and balance, before any potential head trauma occurs. Establishing this neurological standard creates an individualized benchmark for comparison should a concussion be sustained. This proactive approach is a fundamental part of a comprehensive concussion management strategy, especially in high-risk activities.
The Purpose and Structure of Baseline Testing
Baseline testing is commonly administered to individuals who participate in activities with an elevated risk of head injury, such as athletes in contact sports and military personnel. Testing is typically conducted annually, often before the start of a sports season, to ensure the data reflects the individual’s current, healthy neurological state. This process is generally overseen by trained healthcare professionals, including certified athletic trainers, team physicians, or neuropsychologists.
The data collected serves purely as a reference point for post-injury evaluation and is not a stand-alone diagnostic tool for concussion. A concussion diagnosis relies on a comprehensive clinical assessment, including a detailed medical history and neurological examination. Providing an objective measure of the person’s uninjured state, the baseline data allows clinicians to accurately assess the magnitude of any post-injury change.
Computerized Neurocognitive Assessment
The foundation of many baseline protocols is the computerized neurocognitive assessment, which provides objective data on brain performance. These tests measure specific cognitive functions known to be impaired following a concussion, including processing speed, reaction time, and verbal and visual memory. They are designed to be short, timed modules, often taking approximately 20 to 30 minutes to complete.
Common platforms, such as Immediate Post-concussion Assessment and Cognitive Testing (ImPACT), C3 Logix, or Axon Sports, present the user with tasks that resemble simple computer games. For instance, a visual memory module might require recalling the location of shapes on a screen, while a processing speed task may involve matching symbols to numbers. Reaction time is measured precisely in milliseconds, often assessing both simple responses to a single stimulus and choice responses requiring decision-making between two simultaneous stimuli.
The scores generated are not compared to a general population average, but rather to the individual’s own pre-injury performance. This personalized comparison is essential because natural variations exist in every person’s cognitive abilities. The overall assessment provides composite scores that reflect the combination of both speed and accuracy, ensuring that a quick but inaccurate response is not interpreted as good performance.
Physical and Functional Performance Measures
A complete baseline assessment includes measures of physical function, specifically focusing on balance and coordination. The Balance Error Scoring System (BESS) is a standardized field test frequently used to establish this physical baseline. The BESS requires the individual to perform three specific stances—double-leg, single-leg, and tandem—with their hands on their hips and eyes closed.
Each stance is performed for 20 seconds on both a firm surface and a medium-density foam surface, creating six total testing conditions. A trained examiner observes the individual and counts specific errors, such as lifting the hands off the hips, opening the eyes, or stepping out of position. Each error adds one point to the final score; a higher total score indicates poorer postural stability.
The systematic variation of the stances and surfaces challenges the vestibular, visual, and somatosensory systems that maintain balance. Other functional measures included in a baseline battery are visual tracking tests, which assess eye movements and coordination, and gait assessments. These physical tests provide crucial objective metrics on sensorimotor control, which is often acutely affected by a concussive injury.
Utilizing Baseline Data After Injury
When an injury occurs and a concussion is suspected, post-injury testing is often administered by a healthcare provider, ideally within 24 to 72 hours. The purpose of this follow-up assessment is to compare the new performance scores directly against the individual’s established baseline data. A significant drop or change in scores across cognitive domains or physical function suggests an impairment related to the injury.
For example, a post-injury test showing a slower reaction time or an increased number of BESS errors compared to the baseline indicates a measurable neurological deficit. This objective comparison helps clinicians monitor the recovery process. The baseline data guides the return-to-play or return-to-activity decision, ensuring the individual’s brain function has returned to its pre-injury standard. Returning to full activity typically requires that the individual is symptom-free and their post-injury test results have normalized to their baseline levels.