A Hutt Hospital emergency department nurse hopes his research on rugby players will help people better understand concussion.
Using monitors in mouthguards and behind players' ears, Doug King is collecting data on the number and intensity of impacts players suffer in tackles.
After each game he downloads the information and carries out a series of tests to see whether players show signs of concussion.
He ran the study with the Hutt Old Boys Marist Rugby Club last year and found 19 unrecognised cases of concussion.
He has teamed up this year with the Te Aroha rugby league under-11s and premiers.
The study coincides with increasing concerns about the long-term effects of head knocks suffered in contact sport.
All Black Kieran Read is battling with concussion.
In the United States, research on American football players identified a link between concussion and dementia.
An admission from rugby league great Ian Roberts that he is suffering memory loss resulting from concussion has had a big impact on the sport in Australia.
King believed there were many more head knocks in league and rugby than people realised.
It was not just head-high tackles or players hitting a knee or hip that were of concern, he said. Any blow to the head could damage the brain.
The implications of his research could be far-reaching.
American football players with dementia are taking legal action seeking financial compensation.
It was clear that on-field concussion was not always recognised, King said.
Backup tests, involving players who left the field being asked to remember numbers, provided another way of diagnosing concussion, and if a player failed the test he could be referred for medical advice.
The $30,000 research project is funded from Australia because King could not get anyone to back it here.
Te Aroha played Randwick last Saturday and tests after the game showed all Te Aroha players came through unscathed.
Te Aroha coach Powhaitere Keelan said the club was right behind the study.
At club level, league was an amateur game and player safety was the priority, he said.
Players inevitably suffered head knocks.
"Players have families to go home to and most of them work. They need to protect their livelihood," he said.
Randwick coach Daniel McEwan said anything that increased understanding of the effects of injuries "is a good thing".
"There is a lot we don't know about concussion," he said.
King said there was a common misunderstanding about headgear that some players wore.
That stopped cauliflower ears and head cuts but was useless for stopping concussion, he said.
It was the same with mouthguards, which protected teeth but not the brain.
King has one PhD and is using his research as he studies for another.
Next year he will focus on female league and rugby players.
They often did not have the back, neck and shoulder muscle strength of men, he said, making them more susceptible to "rotational" injuries because their head was not as stable.
King's goal is to produce a test that can check on the health of every player after a game.
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