THERE is still not enough information available to put a serious dent in the AFL's most common injury, says the author of a new study into predicting hamstring strains.
The AFL's 2016 injury report shows inroads are being made into reducing hamstring setbacks, but the issue still costs footballers far more matches than any other ailment.
Hawthorn's Cyril Rioli and Geelong's Nakia Cockatoo are two players who suffered repeat hamstring problems, while the same injury played a role in Magpie Ben Sinclair's retirement last year.
The 2017 injury report is still being completed.
Clubs lost an average of 24.3 games from players with hamstring strains in the 2007 season and that number dropped to 19.7 in 2016.
But that was still well ahead of anterior cruciate ligament knee injuries (12.9 matches) and ankle sprains or joint injuries (9.9).
PhD student Josh Ruddy's study was the first to investigate if three key risk factors – age, past hamstring strains and low levels of eccentric hamstring strength – could be used to predict when such a strain would occur in AFL footballers.
Eccentric hamstring strength relates to the hamstring muscle's ability to resist lengthening, and the theory is athletes that can resist that lengthening are less likely to sustain injuries.
Ruddy, an award-winner in injury prevention studies who attends Australian Catholic University, identified patterns in data gathered in 2013 to predict what "should" have occurred in 2015.
Those predictions were then compared to what actually happened that season.
Almost 200 AFL footballers and five clubs were involved in the data-gathering process in each of the years.
Ruddy found that risk factor data could not be used to "identify athletes at an increased risk of a hamstring strain with any consistency".
The 2015 group's eccentric hamstring strength was better than their 2013 counterparts – possibly as a result of David Opar's and Tony Shield's groundbreaking study – but did not result in fewer strains.
Ruddy, who works closely with the Melbourne Football Club, said he and colleagues involved in the study still believed eccentric hamstring strength was critical despite the finding.
"If you think of it as a big pie, we currently have only a very small slice of it. There are a lot of questions and factors in why the injury is occurring," he told AFL.com.au.
"We'll never be able to predict injury with 100 per cent accuracy and prevent all injuries occurring, but the more injury data we can get, perhaps, we can build on this.
"Ultimately, if we can predict injury with any sort of accuracy, we will go a long way to preventing it."
But Ruddy said a major breakthrough in sports-related hamstring research could still be a decade off.
"I think a big factor is going to be the rapid increase in the technology we see," he said.
"We've got players wearing GPS units and they give us a lot of information and we can use that information really well.
"(New technology) will play a huge part in us narrowing down some of those specific risk factors and really monitoring players, and in real time – in games – and look at how they're moving."