When those images of Saracens players wearing what looked like a jumbo-sized plaster underneath their right earlobes against London Irish were broadcast last week, the initial reaction was bemusement: what is it? And what does it do? We quickly discovered it had a name: the x-Patch, created by the Seattle-based company X2 Biosystems, to monitor the force of blows to the head. Yet for some the bemusement has lingered.

How else to explain why the Saracens chief executive, Edward Griffiths, felt compelled to respond to accusations the device was a “gimmick” a few days ago? As Griffiths made clear, Saracens are trying to rake deeper into the potential dangers of head trauma to provide a greater duty of care to their staff. As he put it: “I don’t want to be visiting these players in 20 or 25 years time in a hospital where they are suffering from dementia or some other neurological condition.”

How great are those dangers? Well, in the past fortnight the first study into the frequency and magnitude of head impacts in rugby union has been published and the results emphatically reinforce Griffiths’ concerns.

The research, conducted by the Auckland University of Technology and published in the American Journal of Sports Medicine, examined every hit sustained by a single amateur rugby union team in New Zealand during the 2013 season by using a high-tech X2 mouthguard. This enabled the academics to monitor not only direct impacts to the head (measured by G-force) but also rotational acceleration of the brain after a hit (ie how much the brain spins measured in radians per second squared).

To put it simply, imagine a car going from 0-60mph in a straight line. That is a form of linear acceleration. A child spinning a top is an example of rotational acceleration. The technology also let researchers see where every hit landed on the head and how long it lasted.

So what did the study find? Across the 19-match season, the premier-level squad experienced 20,687 impacts to the head greater than 10g which is roughly the impact of a light punch (the hits ranged from 10g to 164.9g). That works out an average of 77 impacts to the head per player-position per match or 1,379 per season.

As the researchers noted, while the majority of these impacts were in what they called “the low injury impact severity limit” (less than 66g and less than 4600 rads2), there were 181 impacts greater than 95g and 4,452 impacts greater than 5,500 rads2, figures that were “above the injury-risk limit”.

This is virgin territory and only a few sports have undergone similar scrutiny. But as Doug King, one of four academics involved in the study, told me: “The research shows there are repetitive sub-concussive impacts to the head in rugby union and when compared with American football, in some cases these are higher in frequency.” And we all know the dangers of American football.

High school American footballers suffer around 16 to 29 impacts per game which is far fewer than those experienced by rugby players in the study. And the average impact of a hit in the rugby study – 22g – is similar to research into high school football too.

Remember also that academics examined amateur rugby union players. We don’t know exactly what level of damage the bigger, stronger and faster professionals would cause but it would undoubtedly be greater.

Which is why Saracens’ approach is so refreshing. As Biosystems’ chief executive, John Ralston, told me, the team are wearing it in practice as well as matches and will shortly be able to use wireless technology which will enable coaches to immediately scrutinise the size, severity, and location on the head of every hit.

The device is already in the NFL and NHL and, as of the coming season, will also be used by all 20 Major League Soccer teams. As Dr Matt Matava of the NFL Physician Society explained last year, the technology “has allowed us to accurately diagnose concussions immediately following an injury [about six-eight minutes after a hit]. The software also allows us to compare the players’ injury date to their baseline in order to objectively assess changes in mental status”.

The device works both ways, too. It not only protects players from harm, it can also tell officials that someone is fit to continue. Intriguingly, it also allows coaches to trigger an alert if a player suffers a particularly big hit or if a player suffers a number of sub-concussive impacts over a game or practice session.

Because that’s the thing with head injuries. It’s not only the highlight-film smashes we should fear: it’s the series of minor hits that can make a player more susceptible to lasting brain damage; more susceptible to motor function and memory issues; more susceptible to impaired co-ordination, vision and speech; and more susceptible to emotional and behavioural changes, including depression and anxiety.

This is big stuff and it needs the big people in sports to accept it is a problem and work towards solutions.

Indeed the more you speak to physicians, sports scientists and academics in the field, the more it hits home. What Griffiths is doing at Saracens is not a gimmick – it’s a potential game-changer.