HIA under increased scrutiny after controversy surrounding Murray and Sexton incidents
It is the topic that rugby would rather didn't dominate the agenda after an exciting weekend of action, but concussion and the management of head injuries remains front and centre of the oval-ball world after high-profile incidents involving two of Ireland's most important players.
Both Conor Murray and Johnny Sexton have come through their pitch-side assessments and subsequent tests and are set to be available for selection this weekend, but the manner in which they returned to the field of play has been met with scepticism.
Tournament organisers EPCR will look into the incident that saw Murray continue to play after a heavy collision with Glasgow's Tim Swinson on Saturday. The Munster scrum-half lay prone before receiving lengthy treatment from the province's medical team and continuing.
Minutes later, having reviewed footage, the Munster medics opted to call the Ireland star ashore for a second look, but he passed the dressing-room Head Injury Assessment (HIA) 1 and came back on to finish the game, passing the HIA 2 test afterwards.
The 'Untoward Incident Review Group' are set to convene later this week to determine whether Munster did anything wrong.
Less than 24 hours earlier, Sexton was hit high and late by Montpellier out-half Frans Steyn and received lengthy treatment on the pitch before heading for the dressing-room.
According to Leinster head coach Leo Cullen, he "flew through" the HIA 1 and Leinster have confirmed that he passed the subsequent HIA 2 and 3 tests without displaying any symptoms.
The swiftness with which he returned came in for some criticism even though there is no obligation on the province to spend the entire 10 minutes allotted conducting the test.
Both Leinster and Munster are following the process put in place by World Rugby, but that HIA process and the protocols around recognising and removing concussed players is under more scrutiny than ever before.
There is a lobby who believe that the need for a HIA is evidence enough of a suspected concussion to remove the player from the game permanently.
The most vocal critic of the process, Dr Barry O'Driscoll has consistently maintained that the 10 minutes allotted for the test is not enough time to diagnose or clear a player of concussion and he has insisted that both Murray and Sexton should not have continued.
At all levels below the professional game, the policy is that a player is instantly removed if a head injury is suspected.
However, the professional game adopted the HIA process into law in 2015, having previously trialled it. It allows doctors to temporarily replace a player suspected of suffering a head injury to the dressing-room for memory and cognitive tests and also to review footage of the incident.
Former Ireland medic Dr Éanna Falvey has spoken of the benefit of the HIA in terms of convincing the injured player to come off the field.
"The hardest guys are the players. From my perspective, professionally, the pitch-side concussion assessment was a godsend," he said in an interview with this newspaper last year.
"Lots of people were critical of the process when it came out, saying five minutes wasn't enough.
"But, the research out there from the 2011 World Cup showed that you had 56 seconds from the player going down to play starting again to get it right. You didn't have long enough, and then getting the player off the pitch was virtually impossible.
"With the HIA, if you're absolutely certain the guy is not coming back on, you can say, 'come off and we'll have a look. If everything's okay you can come back on again'. It's much easier to keep somebody off than get them off."
However, Falvey's predecessor Cliff Beirne yesterday questioned whether the test is fit for purpose.
"I would really have to call into question whether it is," he told RTÉ. "I feel it is a very blunt instrument to assess a complex injury in a very short time.
"This should be looked at independently by people who have no skin in the game, who are genuine experts, and see whether it is fit for purpose, and whether we continue to use it.
"World Rugby can play with words in whatever way they wish on this, but we know that if a player fails it, yes, they are concussed. But if they pass it, in my opinion, it doesn't mean they are not concussed.
"You can't just be investigating the protocols, and placing the doctors under even more scrutiny and pressure."
The issue has been in focus in the aftermath of the George North furore and the comments of former Clermont second-row Jamie Cudmore - who claims the Top 14 club failed in their medical duty to him by sending him back on after he failed a concussion test - while World Rugby increased the sanctions for offences involving the head at the turn of the year.
While they escaped any sanction over the incident, Northampton Saints were criticised by both World Rugby and the English Premiership for their failure to spot their star winger being apparently knocked out cold when he landed heavily against Leicester last month. North passed his HIA in the dressing-room and finished the game, but subsequent investigations have found he should not have done so.
This week, North has accused members of the media of blowing his situation out of all proportion.
Cudmore, meanwhile, has established The Rugby Safety Network after his own experiences and has been on the interview trail telling of his experiences at Clermont, experiences that don't paint a good picture for those who back the HIA.
As a result of the growing profile of head injuries, fans are increasingly aware of the dangers, and that can only be a good thing when it comes to holding those in power to account. On the flip side, it also gives rise to the risk of diagnosis from the sofa as supporters and pundits take to social media to discuss each incident.
On Friday night, Leinster followed all of the protocols and yet they still find themselves at the centre of a controversy, while Munster will defend their medical team.
"Johnny passed it (the HIA) and was back on the field. If he hadn't passed it then he wouldn't have been back on the field," Leinster coach Stuart Lancaster said. "You've just got to trust the medical team. He gets taken off, Ross Byrne comes on, we get the message that Johnny has passed the HIA and as a consequence is back on the field."
Both provinces have recent experience with the seriousness of head injuries. Leinster lost Kevin McLaughlin to retirement last year, while Munster's Mark Chisholm remains on a long absence as a result of the injury and question marks remain over his future.
They are trusting in the process but questions remains over whether the process and the HIA is fit for purpose.