The thing about rugby is it is not a contact sport - it is a collision sport.
Huge athletes (mostly men) whacking into each other at a decent rate of knots. Injuries are bound to happen.
But, while the head may be the most important part of the body, there is still plenty not known about it. That leads to many assumptions and statements.
Some may be true but most still have question marks around them.
When are you concussed and when are you not?
If you have 10 concussions over a playing career of 15 years, is that going to affect your future wellbeing long after you have hung up the boots?
University of Otago sports medicine lecturer Dr Tony Schneiders says there is still no definitive link between concussions in a playing career and brain problems later in life.
''Nothing has been proved yet. More stuff is coming out in the US about it but it has never been fully looked at,'' Schneiders said.
''What needs to be done is you have to have a look at a whole lot of normal brains and get a whole lot of sporting brains and do a comparison between the two. Until that happens, there is a lot of scaremongering out there.''
A consensus statement from the fourth international conference on concussion in sport - a meeting of sporting academics from all around the world - concluded there was no conclusive evidence linking hits to the head during playing days with brain problems later in life.
Scottish Dr Willie Stewart told BBC radio at the weekend he had discovered sections of a rugby player's brain tissue which had abnormal proteins associated with head injuries and dementia.
Stewart said rugby players could be exposed to dementia because of head knocks. But Schneiders cast doubt on that finding.
''You could do a study on one person who has symptoms of dementia and not played sport. To come up with that conclusion and take that line is quite spurious.''
The British Medical Journal reported in March this year ''the speculation that repeated concussion or subconcussive impacts cause chronic traumatic encephalopathy (CTE) remains unproven''.
Some retired American football players are suing the NFL for not doing enough to protect them as they say the brain injuries sustained during their careers are affecting their quality of life now.
Science, though, is still to back up that claim. That is the thing with concussion - there are so many unknowns.
It is not like a dislocated shoulder, after which the player is told to spend three weeks on the sidelines. A head knock could mean a week off, a month or a career.
Schneiders said for 80% of concussion injuries, it was usually 10 days before players could get back into action.
''But there is no magic pill for it. It can be hard to say to young people that you have to have a complete rest. No reading, no gaming or texting. Sometimes just lying in a padded room for a couple of days would be the best idea but that is not really realistic.''
There was no data available on whether more young people were getting concussed but that might be the case.
''Younger kids are bigger than they were. As a species, we have grown four inches [10cm] in the last century. So the hits are going to get bigger.
"They are hitting harder. And there is a lot more reporting of it. People are way more aware of what a concussion is.''
Safer laws were reducing concussion, he said. Shoulder charges had been outlawed in both league and union, for example, but there were still players not declaring a concussion as they would miss a game.
The New Zealand Rugby Union runs a programme where every coach has to learn about issues concerning concussion symptoms and treatment of players.
ACC costs for concussion in rugby are also dropping. With about 150,000 rugby players in New Zealand, and about 1500 claims for concussion, that meant it was affecting about 1% of players.
Schneiders said headgear did not stop concussion, although there was a school of thought that strengthening of necks might help.
NZRU medical director Ian Murphy said rates of recognition of possible concussion were increasing but that did not mean concussions were on the increase.
''We are finding concussion rates are decreasing. With improved tackling technique and awareness there is no evidence concussions are rising.''
Murphy backed the motto of ''if in doubt, sit it out''.
The IRB and NZRU have a study into concussion under way with the Auckland University of Technology.
With regards to Stewart's findings, Murphy said it was notoriously difficult to produce reliable scientific studies which then led to changes for enormous populations.
| ACC claims | ||
| From rugby Concussions | ||
| Year | Number | Cost |
| 2011 | 1502 | $575,120 |
| 2012 | 1618 | $594,070 |
| 2013* | 1029 | $213,570 |
| - * to date | ||
Definition
Concussion is a brain injury and is defined as a complex pathophysiological process affecting the brain, induced by biomechanical forces. Concussion is the historical term representing low velocity injuries that cause brain ''shaking'' resulting in clinical symptoms and that are not necessarily related to a pathological injury.
Source: Consensus statement from the fourth international conference on concussion in sport, Zurich, 2012.
