OVER decades the near everyday use of the word "concussion" in sport has, if you'll pardon the pun, lessened its impact. Recently, however, a reversion to more basic terminology has had a juddering effect on the public consciousness in re-categorising the risks run by sportspeople. Brain injury. Two short, simple words with colossal and complex implications.

What was, historically, known and not known about it by the governing bodies of sport is now being challenged, to the extent that American Football’s NFL has spent hundreds of millions of dollars in settling a class action with former players who claimed their employers should have done more to alert them to the risks they were exposing themselves to. The NFL admitted nothing in that regard and more than 200 of those initially involved opted not to take a share of the settlement as they consider how to take matters further.

The ramifications go way beyond American football because medical knowledge is not confined to any one sport and therefore all those involved in what are known as collision sports are similarly entitled to question the duty of care that was owed to them by those in authority.

Broadcast just ahead of the Rugby World Cup 2015, which is well underway, the timing of former Scotland international player John Beattie’s BBC Panorama investigation into the issue was incendiary, and drew rebukes from some establishment apologists. The programme’s message was immediately reinforced by the near simultaneous announcement of Jonathan Thomas, the former Wales international, that he has been forced to quit playing at the age of 32 because of epilepsy which is thought to have been induced by multiple head traumas.

Thomas describes the effects of his condition as relatively mild but questions have also been raised about the contribution of past collisions to the motor neurone disease that rendered Joost van der Westhuizen – the outstanding individual in South Africa’s Hollywood-glorified 1995 World Cup win – wheelchair-bound with no prospect of recovery from the degenerative condition.

Some attitudes exposed both by the programme and in the reaction to it are deeply dangerous for rugby since they spoke to an almost wilful complacency about safety procedures that have only been introduced as more attention has been focused on the consequences in recent years. Any sort of denial of the sport’s responsibility seems sure to be challenged in the courts.

Those contemplating such action might have been tempted, then, to think they had the ideal advocate to make their case when it first emerged three years ago that Michael Lynagh, once the brilliant playmaker and goal-kicker who helped take Australia from the periphery of the international game to world champions, had, at the age of only 48, suffered a major stroke and then made a remarkable recovery from it.

A long-time television pundit whose understated, analytical style has a lawyerly feel to it, the man who, as a 21-year-old stand-off, helped steer Australia to a breakthrough Grand Slam of wins over England, Ireland, Scotland and Wales in 1984, outlines what happened to him in 2012 in a newly-published book entitled Blindsided, co-written with Scotsman Mark Eglinton.

It is far from melodramatically relayed, but nor are any punches pulled, not least in his account of the stage in his treatment when, both lucid and detached as he lay in agonising pain and freezing in cold sweat in a hospital bed in his native Brisbane where he had taken ill during a working visit, he felt he could take no more and had to accept that he would never again see his wife Isabella and their three young sons, Louis, Thomas and Nicolo, all of whom were still at home in London.

If his account of that is harrowing so, particularly for any parent, is the description of how, as his father Ian sat in a hospital waiting room he spotted, through a window, a doctor examining an X-ray which his personal experience as a clinical psychologist told him showed the patient was in desperate trouble, only to discover soon afterwards that the scan in question was of his son’s brain.

Even before he suffered his stroke Lynagh’s studious approach, which had long separated him from the majority of knee-jerk television sporting pundits, meant he would already have known how the concussion debate was working its way up rugby’s agenda, partly because of the increased awareness generated by the NFL case but also because of the studies being done into the contribution made to illnesses suffered by former sportsmen by the delayed effects of having been exposed to repeated collisions.

Where brain-damaged former boxers would once simply have been dismissed as punch drunk, this modern, more litigious society is inclined to seek to apportion responsibility to those who knew or should have known better when exposing participants to risk. Lynagh’s celebrity could have forced the issue had he been able to persuade himself that his sport and his illness were related to one another. Yet far from seeing this as an opportunity to cash in he is arguably more emphatic than the specialists seem to suggest he could be in dismissing the possibility that the two could be linked.

“They weren’t, because I hadn’t played for around 15 years,” he says. “It was one of the things I asked but it was an artery at the back of my neck that split which was the problem, not something in the brain. I asked if there was a weakness there and they said they couldn’t say for 100 per cent, but it was very unlikely that there was because you would have had symptoms in the lead up in the last 15 years and I just didn’t have that, so they said it was very unlikely that it was from rugby.”

Some might feel the word "unlikely" would be enough to invite further investigation of the correlation. Instead, while unfailingly polite, engaging and pleasant in conversation, Lynagh veers marginally towards abruptness only once at my slightly ill thought through suggestion that if rugby’s medics were to monitor players more closely, particularly following head injuries, not only might they reduce risk at the time but they might also gain early warning of symptoms of potential problems further down the line.

“I hadn’t played for 15 years and had there been a weakness from rugby there would have been symptoms and there weren’t,” he reiterates. “So it’s nothing to do with rugby and it could have happened to anyone. It was a combination of things, having flown from here to Singapore, missing flights. There were other things, sleeping on a plane overnight so you get kinked in your neck or whatever, then going and playing golf in 30-degree heat, and golf can bring it on, then having a sip of beer and having a choking, coughing fit. That was the catalyst. It was just a perfect storm of other things and that was it. It split the artery.”

The full details of how that came about are in the book but his forcefulness on that specific point might almost invite the conclusion that a man whose main legacy of his stroke is a loss of some sight in his left eye, is also choosing to be blind to the dangers of the sport he loves.

Yet while he says there has to be an acceptance that there will be a percentage of any group of people who will succumb to serious illness, that would also misrepresent him since he doesn't shy away from rugby’s need to take its responsibilities seriously and react accordingly.

“Any run of society has this, but in terms of brain injuries, it’s right that there’s a focus on it; it’s right that we should be knowledgeable; it’s right that we should have protocols and that’s all been put into place. It’s a collision sport,” he says. “However, I was talking to somebody the other day who said we should ban tackling from the waist up. Actually that’s not going to change anything either because you still have two blokes clashing heads lower down.

“You have accidents. By putting the right protocols in place and having people go through concussion tests, the medical people in charge of this have got to be responsible. It’s important that they take responsibility and say ‘No, he’s not playing any more. He shouldn’t be out there. He’s coming off,’ no matter what pressure the coaches or anybody else puts on them, or the player themselves. But there should be the right processes and protocols and there are now.”

Furthermore, if Lynagh was simply seeking to offer a defence of his sport it would only be too easy to seize upon crediting the wider benefits of having played the game to the level he did with leaving him residual conditioning that has aided his recovery. All the more so because of the unlikelihood of his survival, as graphically recounted in another passage in the book involving his father when he asked the specialists for the prognosis of the treatment they were applying to his son and was told: "We don’t know because they don’t usually survive.”

To the suggestion that his healthier-than-average life had helped him, Lynagh’s response is also carefully considered. “Not initially, no,” he says.

“It was pure luck that I was OK, but after I came out of the danger period my recovery was pretty good and I guess from a physical point of view I knew my body reasonably well from having been through elite sportsman sort of stuff and then I was also able to set small goals and have that mentality of slowly but surely attaining each one, and then having the mental experience to be able to deal with that. So it definitely helped, not initially when I was just lucky, but once I got out of that it took over more, having been involved in it for so long, knowing physically where you were and how to get rest, all those sort of things were fairly second nature.

“Also the support from the rugby community at large, all round the world, was amazing. That was fantastic. In rugby particularly you rely on other people a lot to play the game. It is a real team sport. Being a fly half, you can’t do anything if you don’t have people who can win the ball and get it to you and others who can run faster and all that sort of stuff, so you rely on other people and that forms strong bonds with people you play with. But having played at that sort of level, you understand your body pretty well and I think it’s more in my makeup as well that you come out of it and say to yourself: ‘OK, this is goal-setting and you have little bits every day, sometimes a bit more.’”

Speaking to Lynagh and reading his book is a reminder of the balance that must be struck between the risks we take and the rewards or benefits we gain from taking them. Poised as he always was on the field of play, this is someone who seems always to have been more aware of that than most and, through this most traumatic of experiences, has merely had his world view reinforced.

Just as we benefit from describing concussion as what it truly is, so there seems much to gain from being reminded by an intelligent, thoughtful individual that before too many eyes light up at the prospect of big pay-outs, those who have been involved in sport must consider what they have gained as well as anything they may have lost.

Blindsided by Michael Lynagh with Mark Eglinton is published by Harper Sport, priced £20.