Why all Super Rugby Pacific players are now wearing ‘instrumented’ mouthguards tracking their every move

7:28 am on 23 February 2024
Angus Ta'avao.

Super Rugby Pacific players are all now required to wear an 'instrumented' mouthguard. Photo: Andrew Cornaga/www.photosport.nz

The rollout of smart mouthguard technology across the Super Rugby Pacific competition this season is causing angst for some players and coaches, after a long list of concerns were raised following its use for women's internationals late last year.

The instrumented mouthguards, which measure head acceleration events, will debut in Super Rugby after World Rugby mandated the use of the technology across all elite competitions from 1 January.

The technology is considered a "game-changer" for player welfare, helping matchday doctors to identify players that need a head injury assessment (HIA).

Statistics provided by World Rugby indicate around 18 percent of concussions become apparent only when a player reports them after a match. The new approach will ensure that anyone who experiences a crunching hit that is not spotted by the TV cameras - or who does not show concussion signs and symptoms straight away - will no longer remain on the pitch.

Instead, when the mouthguard registers a head acceleration event over a set threshold, it sends an alert to an app that is held by the independent matchday doctor to let them know that the player requires an HIA.

Although smart mouthguards have been trialled for several years, it is only recently that advances in technology have enabled data to be transmitted in real time rather than having to be downloaded after the match, allowing the system to be integrated into the HIA process for the first time in the new WXV competition in October.

Amy du Plessis of New Zealand makes a run. Black Ferns v France, World Rugby WXV1 women’s rugby union match at Sky Stadium, Wellington, New Zealand on Saturday 21 October 2023. Photo credit: Elias Rodriguez / www.photosport.nz

The smart mouthguards were used in a Black Ferns clash with France last year, where five players were taken off for HIAs, overwhelming medical staff Photo: Photosport/Elias Rodriguez

Teething problems

But teething problems were evident from the outset, with the Black Ferns' opening game against France descending into chaos with five players removed from the field to undergo an HIA overwhelming the medical staff and wreaking havoc on the respective team's substitution plans.

Statistics provided by World Rugby indicate that over the 27 games across the three-tier competition, there were 30 "unique alerts" - meaning the players did not display any on-field symptoms, but experienced forces which triggered the mouthguard. Of those 30 alerts, three players were unable to return to the field following an HIA.

This average of around one additional HIA per game during the tournament is in line with World Rugby's initial projections of 0.9.

Other complaints to surface included the discomfort of the specialised mouthguards, difficulty speaking and communicating with teammates when the mouthguards are in, ethical concerns about increased player surveillance, and questions about the fairness of a mandate requiring the players to wear the mouthguards for all contact training.

NZ Rugby medical manager Karen Rasmussen said following feedback from the WXV teams, World Rugby has reviewed the thresholds that trigger an alert.

"What they found was that there were a lot of players that were coming off in the match when the threshold was lower that probably didn't need to be coming off. So they were overwhelming the matchday medical staff plus you had players and coaches that weren't happy. So they've looked at the data again," said Rasmussen.

Martha Mataele of Canterbury celebrates her try during the Farah Palmer Cup round four match between Counties Manukau and Canterbury at Navigation Homes Stadium in Auckland, New Zealand on Saturday August 06, 2022. Copyright photo: Aaron Gillions / www.photosport.nz

The mouthguards were also trialled in last year's provincial Farah Palmer Cup Photo: Photosport/Aaron Gillions

The instrumented mouthguards contain an accelerometer and a gyroscope that enables them to measure both linear and angular acceleration of the head.

The world governing body initially set alert thresholds at 70g for linear accelerations for men and 55g for women, while the trigger for angular acceleration is 4000 radians per square second (rad/s) for both. Those numbers have since been raised to 65g for women, and 75g for men, and 4500 rad/s.

Dr Eanna Falvey, World Rugby's chief medical officer, said the WXV tournament revealed a significant gap in the data for women's rugby, which resulted in the initial threshold being set too low.

While extensive trials were held over the last four years, Dr Falvey said these were in semi-professional competitions, where there is still a wide range in skill level between the athletes.

"It was very important for us to get it in [to the WXV] because we want to increase our pool of data and understanding of the women's game as a priority. It has lagged behind," he said.

"A lot of our data was gathered in the [English women's premiership] and Farah Palmer Cup. And in the Farah Palmer Cup in particular, you have a mixture of elite athletes and amateurs, and it may be that some of the intensity of those competitions was lower."

World Rugby has applied the same rationale to slightly tweak the threshold for the men's professional game, and they are confident they have got it right - early figures out of the Six Nations Championship in Europe indicate there has been just one "unique alert" triggered over the first two weekends.

Iritana Hohaia Injured at the Black Ferns VS Wallaroos O'Reilly Cup match at FMG Stadium, Hamilton, New Zealand on Saturday 30 September 2023. Mandatory credit: DJ Mills / www.photosport.nz

Black Fern Iritana Hohaia is checked by a medic during a clash with the Wallaroos in last year's WXV competition Photo: Photosport/DJ Mills

Brain injury risks

The new mandates come as the game's leaders continue to wrestle with how to keep players safe, with a wealth of research now available that links repetitive blows to long term brain injury.

World Rugby is also fending off several legal challenges. In 2020, more than 200 former players, including All Black great Carl Hayman, brought a lawsuit against World Rugby along with the Rugby Football Union and Welsh Rugby, accusing the governing bodies of failing to take reasonable steps to protect players.

The smart mouthguard technology is one of several measures World Rugby has introduced in an effort to make the game safer alongside lowering tackle heights and changes to the carding system. These changes have not always been popular, pointing to an ongoing tension in the game.

While the wider rugby public have reached a point where it recognises that strong concussion management protocols and player welfare is a good thing, that perspective can shift when the rule changes or HIA protocols impact the game, leading to accusations rugby bosses are "killing the game" or "wrapping the players in cotton wool".

Falvey said those criticisms can be frustrating when so much is at stake.

"We sometimes see retired players who played in a different era being quite outspoken about the rule changes and being less understanding of the need for us to manage this properly. All in all though I think most people understand that we need to treat this seriously, we need to look after people properly and most importantly, we need to try and prevent [head injuries] happening.

"That has led to controversial decisions in some very big games - none other than the World Cup final. And I think people are naturally disappointed when these things happen. But people also understand that we are trying to look after our players the best way we can."

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