Understanding the DAMAGE Severity Index (DSI) Scores in HITIQ PROTEQT
April 2026
This is a citation of the DSI scoring method utalised for quantifying head impacts in the HITIQ PROTEQT system. These scores are based off the work of Tautau Wu and colleagues. based out of the Center for Applied Biomechanics at the University of Virginia.
Link: https://pubmed.ncbi.nlm.nih.gov/34897386/
DSI
The DSI number is not just an arbitrary score; it is a mathematical, mechanical calculation derived from peer-reviewed research and real-time head movement data. When the DSI score is high (greater than 75), it indicates that the head has experienced significant twisting forces, which - based on the data points from this study – which correlate with increased risk of brain tissue stretching and injury.
The HITIQ PROTEQT system enables you to quantify and track the cumulative mechanical impact an athlete experiences over time, helping to maintain safer exposure limits.
The role of HITIQ iMG
Instrumented mouthguards capture many data points in a high-fidelity manor of head kinematics. Traditionally, simple metrics from the output of iMG data cannot infer or accurately illuminate head injury risk alone.
The HITIQ PROTEQT mouthguards capture and calculate Diffuse Axonal Multi-Axial General Evaluation (DAMAGE) which this paper describes as the best way to predict how the brain stretches during a head acceleration event. One of the key outputs is that this metric considers the angular motion of within its calculation which is described as the primary cause of brain deformation and injury. DSI then scores this complex metric into a simple number 0-100 to demonstrate severity of the impact.
Using Computer Models to map Brain Strain
To understand how much force a brain can withstand, researchers from the University of Virginia and other global institutions involved in this research conducted a study using a modest database of 466 impact cases. This included data from professional football collisions, safe human volunteer tests, and animal studies.
By using advanced computer "Finite Element" models - digital maps of the brain - the researchers could simulate exactly how much the brain tissue stretched during these hits. In this study, they found that traditional measurements, like how fast the head moves in a straight line, are not as accurate as measuring how the brain "sloshes" or twists inside the skull.
High Impacts and Brain Strain Risk
In the PROTEQT app, the complex math is simplified into the DSI (Data Severity Index). When a player wears the HITIQ mouthguard, it captures the exact head movements described in this study and converts them into a DSI number.
- The Key Metric: DAMAGE
- The study highlighted a specific measurement called DAMAGE (Diffuse Axonal Multi-axial General Evaluation).
- Why it matters: DAMAGE was found to be the best overall way to predict how much the brain tissue actually stretches.
- What it measures: It looks at "angular motion"—the twisting and rotating of the head—which is the primary cause of brain deformation and injury.
In the PROTEQT app, this complex math is simplified into the DSI (Data Severity Index). When a player wears the HITIQ mouthguard, it captures the exact head movements described in this study and converts them into a DSI number.
Risk Curves Determine Brain Strain Risk
The research established "Injury Risk Curves" to determine the probability of an injury based on the DAMAGE score. The number 75 is set as an in app threshold. According to the study’s findings, a DAMAGE value of approximately 0.75 (which equates to a DSI of 75) represents a critical point on the risk curve. This was then validated, as the statistical risk for a Mild Traumatic Brain Injury (mTBI), such as a concussion, increases significantly at this point. Specifically, the study indicates that at a metric value of 0.75, there is roughly a 75% probability (P=0.75) of sustaining an injury classified as mTBI.
Because the risk of injury rises so sharply at this level, the app flags DSI scores of 75 and above as "High Impact" to alert parents and coaches that the hit was severe enough to reach a high statistical probability of injury.
How this relates to the HITIQ DSI (Damage Severity Index)
If you are looking at a DSI score in the app, you are seeing the real-world application of the science described in this paper. Here is how they connect:
- Translating Motion into Meaning The paper mentions using "kinematics-based metrics" (the measurement of head movement). When a player wears an instrumented mouthguard, it records those exact movements in real-time. The DSI takes those raw numbers - how fast the head rotated and accelerated - and uses the same logic as the "injury risk curves" mentioned in the study to give that hit a score.
- The "Tissue-Level" Connection The researchers in the paper used computer models to see how brain tissue deforms. The DSI is designed to represent the intensity of an event by considering these same factors. A high DSI doesn't necessarily mean a diagnosed concussion, but it indicates the head experienced the kind of "twisting" forces that the study identifies as high-risk for brain tissue stretching.
- 3. Contextualising "Sub-threshold" Hits The study specifically looked at "sub-injurious" data – or hits that didn't cause a concussion but still put stress on the brain. This is why the app tracks even smaller hits. Just as the researchers used that data to understand the full spectrum of brain safety, the DSI helps you monitor the "load" or total amount of impact a player is taking over a season.
The DSI is essentially a simplified "risk gauge" built on the complex math and brain-modeling techniques described in this paper. It turns invisible brain physics into a number you can use to monitor a player’s safety.
