At CEPSUM, the University of Montreal’s football complex, a red warning can flash on a tablet before a player says he feels anything wrong. The alert marks a measured head impact, giving the medical team another reason to check in.
Concussions often bring clear signs such as dizziness, headaches and confusion. But research led by Louis De Beaumont, a clinical neuropsychologist and professor in the University of Montreal’s Department of Surgery, points to a harder-to-spot risk: a hit can change brain activity before recognizable symptoms appear. A blow can disrupt cerebral homeostasis, the brain’s ability to keep the conditions inside it balanced.
Since the start of the 2026 season, every player on the university’s Carabins football team has worn a Catapult sensor vest. It tracks measures including heart rate, running speed, acceleration and movement. Players also wear Prevent mouthguards fitted with instruments that record the force, location and origin of impacts. The information reaches De Beaumont and his students on the sidelines almost instantly.
A hit measuring 40 g—40 times the force of gravity—can be linked to measurable changes in brain physiology, De Beaumont has found. The figure is a research benchmark, not a medical test for concussion. When the system records an impact above 40 g, an alert appears on the screen. Students on duty pass it to Patrick Gendron, the Carabins’ physical therapist, who has worked with the team since 2007. The medical staff can then consider what happened, how the player feels, whether symptoms are present and whether he should leave the game.
The alerts matter because staff cannot watch every player at once. “Even though there are two physical therapists, and one of us is always watching the game, we can’t see all 12 of our players at once,” Gendron said. “We regularly miss hits.” Data from the mouthguard can draw attention to a player who might otherwise not receive a closer assessment. It also gives staff a specific impact reading to help guide their questions.
The measurements need human judgment, too. Jeanne Bellerose, a doctoral student in neuropsychology, said the team watches the game because readings can be skewed—for instance, if a player handles his mouthguard while sitting on the bench. Sensors can point to a possible concern, but they do not replace an examination by medical staff.
After games, De Beaumont’s team tests players whose recorded impacts reached 40 g or more. The checks include blood tests for markers of the brain and body’s response to impact and inflammation, tests of eye movements and balance-related function, and pupillometry, which measures how pupils widen and narrow. The researchers are working with the Carabins’ medical staff and other teams in Quebec’s student sports network, the Réseau du sport étudiant du Québec.
The project is testing whether real-time impact data can help staff notice possible injuries sooner and study the effects of repeated blows. By combining sensors with on-field observation and postgame tests, the researchers aim to improve prevention and support student-athletes’ health. The 40 g alert is not a diagnosis; it is a prompt to pay closer attention.