The whistle blows. A player goes down. It’s rugby, so hard hits are part of the game. But sometimes, a hit is too hard. It’s more than just a bruise. It’s a concussion. And for too long, the brain’s invisible injuries went unchecked, masked by adrenaline and a warrior’s resolve. Shane Christie, a New Zealand rugby player, suspected the silent damage multiple concussions caused. He wanted his brain studied after death, a grim hope to make the game safer. He died at 39, leaving behind a legacy of a critical question: how do we protect the players?

Now, World Rugby is fighting back with a new weapon: smart mouthguards. These aren’t just for protecting teeth, although they do that too. These are intelligent devices, designed to shine a light on the hidden trauma of head impacts.

The Silent Alarm

Picture this: a player takes a heavy tackle. Instantly, an LED on her mouthguard flashes red. The referee stops play. The player is off for a Head Injury Assessment (HIA). This isn’t a guess. It’s a direct alert, triggered by sensors in the mouthguard that detect significant linear and rotational accelerations in the head.

Dr. Lindsay Starling, a science and medical manager at World Rugby, noted that this system creates immediate awareness for both match officials on the field and fans watching at home. It’s a stark, visible signal that a player has sustained a potentially concussive impact.

This technology is rolling out across elite rugby, with a major debut at the Women’s Rugby World Cup 2025. Dr. Éanna Falvey, World Rugby’s chief medical officer, confirmed that nearly every player at the Women’s World Cup will wear these new mouthguards, a higher rate than in the men’s game. These smart devices are a significant upgrade from older Bluetooth systems that could take precious seconds to deliver an alert.

Beyond the Field: The Data War

The mouthguards work by continuously measuring head movement during collisions. For women, a flash occurs if the mouthguard registers an acceleration above 65g and 4,500 radians per second squared; for men, the threshold is 75g and 4,500 rad/s2. These are not mere diagnostics, as Prevent Biometrics CEO Mike Shogren emphasized; they are data collection devices. “If you don’t have the data, you can’t do much,” he said.

This initiative aims to augment the existing HIA protocol and build a robust dataset for long-term study of head impacts. Already, this effort has collected data from 400,000 head acceleration events and 75 concussions.

Falvey highlighted that the mouthguard isn’t a “concussion detection device” but rather a tool to “pick up a large impact”. Concussion remains a clinical diagnosis, considering factors beyond just the impact, such as a player’s history and age. However, these alerts are proving vital, adding an average of one extra stoppage every three games and correlating with 43% of total concussions.

Player welfare is paramount. Research indicates that every 15 minutes a player continues to compete after a concussive event, their recovery time is extended by three days. This technology helps ensure players are removed for assessment, mitigating further risk. The diagnostic accuracy of the HIA protocol, already around 88%, is expected to improve further with the integration of these smart mouthguards.

Pilot study in the Netherlands

The pilot study in the Netherlands is a crucial development in enhancing player safety in rugby, spearheaded by Liam Paget. Paget is an orthopedic surgeon in training at Amsterdam UMC and also serves as the head of medical support at the Amersfoort rugby club, Eemland. Eemland is the rugby club taking part in this new pilot, where players will wear smart mouthguards with sensors during matches to detect serious head injuries at an early stage.

The importance of this pilot study is multi-faceted:

• Safeguarding Player Safety: Paget’s primary motivation is to safeguard the players’ safety. He noted that in the Netherlands, sports medical support often has a low priority, with many clubs lacking a physiotherapist and settling for only a sports masseur. He aims to change this situation by setting an example with a rugby team.
• Addressing Injury Risks: Rugby is a contact sport where a large number of players get injured, frequently experiencing concussions. Paget emphasized that “certain twisting movements can impact the brain”.
• Gaining Deeper Insight: The initiative, undertaken with Prof. Gouttebarge and Prof. Kerkhoffs of Amsterdam UMC, seeks to gain more insight into the impact of head knocks and to better understand the problem, particularly how repeated impacts can contribute to brain injury.
• Scientific Validation and Future Funding: Paget stresses that prevention is the priority and that scientific support is essential for the future. This research is needed to sustainably finance future safety initiatives.
• Progressive Innovation: World Rugby supports the introduction of smart mouthguards at a professional level, viewing it as an example of a progressive innovation policy by the global governing body to raise awareness about high-risk sports.
• Broader Impact: Approximately two hundred players in the Netherlands, across youth, senior men’s, and women’s rugby divisions, are expected to join this project. The pilot is anticipated to start this year, pending final financial funding.

Paget observed firsthand the professional medical support in top South African sides and was impressed by their alertness to player well-being, paying attention to even the smallest details from stretching routines to warm-ups. He hopes to bring a similar level of dedication to medical support in Dutch rugby through this pilot.

The Long Game: Shaping the Future

The insights gleaned from this data are powerful. Dr. Starling mentioned the potential for mouthguard data to inform investigations into foul play, though she cautioned against over-relying solely on the data. Falvey noted a striking example where one player in a particular position experienced nearly six times the number of impact events compared to others in the same role. This data can pinpoint poor technique or high-risk playing styles, leading to targeted coaching interventions and potentially, rule changes.

Pilot studies, like one at rugby club Eemland in the Netherlands, are also underway, eager to understand the actual forces at play in contact rugby. This scientific backing is crucial for sustainable, long-term safety initiatives.

But for all the advances at the elite level, a deeper challenge looms, particularly at the grassroots. Liam Paget, highlights a stark reality: in many countries, sports medical support often takes a low priority, with clubs frequently lacking a physiotherapist and settling for a sports masseur. This presents a significant funding conundrum. Paget stresses that scientific support is essential for the future to sustainably finance future safety initiatives, and this research is needed now to ensure long-term funding.

This issue directly impacts player safety and raises concerns for new athletes and their parents. Prevent Biometrics CEO Mike Shogren articulated this clearly, identifying the “fear of concussions” as the single biggest limiter to growth for contact sports. If not adequately addressed, and without the scientific backing that robust, funded research provides, this apprehension could significantly impact rugby’s ability to attract new players, particularly in youth divisions, and, by extension, threaten the very longevity of the sport itself. The Eemland pilot, for instance, is still awaiting its final financial funding to fully commence this year, underscoring the ongoing challenge.

While traditional mouthguards and headgear have consistently shown little evidence in reducing the incidence or severity of concussions, their role in preventing dental and superficial head injuries is well-established. The new instrumented mouthguards are not about preventing impacts, but about detecting them with unprecedented accuracy. This validation is critical for confidence in the technology.

There are challenges: false positives can occur when players remove or adjust their mouthguards. Proximity sensors could address this in the future. But the commitment is clear. From preventing immediate further injury to informing long-term changes, the data from these smart mouthguards can give World Rugby a clearer picture of the brutal ballet on the pitch. It’s a fight for player safety, one impact at a time.