Elite rugby players in the UK will wear instrumented mouthguards and give blood samples before and after matches to pinpoint exactly which head impacts cause brain injury. The fundamental problem is that no one knows the precise biomechanical threshold—the force, acceleration, or strain—at which a hit to the head produces measurable brain damage. Without that threshold, doctors cannot tell which impacts are dangerous, and engineers cannot design better helmets, headgear, or vehicle safety systems. The study will recruit 600 players (half women) over two seasons, combining mouthguard kinematic data with computational brain models and blood biomarkers such as GFAP, UCH-L1, and NFL measured on Simoa and Nulisa platforms. If the research succeeds, it will produce the first objective, evidence-based thresholds for traumatic brain injury. Those thresholds could transform how head impacts are triaged on the pitch, in military field hospitals, and at roadside collisions. They would also give designers of protective equipment—from rugby scrum caps to car interiors—a concrete target to engineer against. The data will be shared publicly through the MRC’s TBI-REPORTER platform, making it available for future studies across sports, military, and civilian settings.
View original technical description
Traumatic brain injury (TBI) is caused by external forces that injure the brain. However, the biomechanical threshold for head impacts that result in TBI is largely unknown. This fundamental gap in knowledge limits our ability to: (a) identify head impacts that have a high risk of causing significant TBI; and (b) design appropriate protective strategies for TBI occurring in both sports and non-sports settings. Until recently most sports head injury work has focused on identifying and managing the signs and symptoms of head injury (concussion). It has not been possible to collect large-scale data about the biomechanics of head impacts or objective biological markers of brain injury. The 2024 MRC Concussion Research Forum highlighted this problem and called for an improved understanding of the links between head impact exposure, brain injury and clinical presentation. Elite men’s and women’s rugby union and rugby league provides an ideal environment to perform the research needed. Detailed head injury clinical assessment protocols are mandatory in professional rugby and are implemented both on match day and during the recovery period. Furthermore, since 2022 elite rugby players in the UK have been wearing instrumented mouthguards (iMGs) that accurately measure the kinematics experienced during a head impact. In partnership with rugby authorities and benefiting from a £3.1 million in-kind contribution that provides the infrastructure, the Traumatic Brain Injury Thresholds Study (TBI-TS), will combine kinematic information about head impacts collected using iMG data, advanced computational modelling and blood biomarker assessment to clarify which head impacts lead to objective evidence of brain injury. This will allow us to define TBI thresholds that inform brain injury risk and assist in prognostication. Over 2 years from September 2025 we will collect data from the 2025/2026 and 2026/2027 seasons in elite rugby union and rugby league. We will recruit 600 players (50% female) to undergo blood sampling at multiple time points (pre- and post- game). Blood-based biomarkers of brain injury will be measured using capillary blood sampling. Gold standard Simoa biomarker assays will be used (GFAP, UCH-L1, NFL, Brain Derived Tau), as well as discovery work using the Nulisa platform that provides 120 brain injury, inflammatory and neurodegenerative biomarkers. Instrumented mouthguard data will be available for all players. Kinematic information will be related to forces within the brain estimated by the Imperial College Finite Element Model of TBI Biomechanics, which provides anatomically precise patterns of brain strain. We will investigate the relationship between kinematics and brain tissue biomechanical measures and: (a) blood biomarker evidence of TBI; (b) clinical measures recovery including symptom resolution and return to play. Biomechanical injury thresholds for clinically relevant TBI will then be established. The work has the potential to transform TBI care through: (a) improved understanding of the biomechanical causes of TBI and their relation to blood biomarkers of brain injury; (b) the identification of objective biomechanical thresholds for TBI; (c) the development of clinical risk profiles for different types of head impact; and (d) the collection of a unique large-scale data set that will be shared through the MRC funded TBI-REPORTER platform. It will improve TBI prediction in a wide range of settings, including elite and amateur sport, military scenarios and road traffic collisions, as well as inform the design of TBI protection strategies.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know