HAMSTRING strains remain AFL clubs' biggest injury headache, highlighted in the release of the competition's 2017 injury survey.

They remain the AFL's most common ailment and cause for missed matches, with 4.9 new incidences per club last year resulting in 16.6 games spent on the sidelines. 

The good news is those numbers were the lowest in seven seasons, representing a small drop from each of the previous four years and 4.9 matches saved compared to 2012.

Clubs lost an average of 25.8 games to hamstring strains a decade ago.

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The recurrence rate for hamstring injuries of 14 per cent last season is also trending in the right direction after being as high as 27 per cent in 2008.

But it is still a problem area despite the obvious progress.

Adelaide suffered through a hamstring epidemic this season, with its players at one stage sustaining nine such injuries in a seven-week period after new training methods were trialled. 

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The survey results follow award-winning PhD student and hamstring specialist Josh Ruddy telling AFL.com.au in January there was still not enough information to significantly reduce these injuries.

"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," Ruddy said at the time.

"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." 

GUESSING GAME Can you predict a hamstring injury?

There were fewer injuries per club than 2016 (35.1, down from 37) and the recurrence rate (eight per cent) dipped into single digits for the first time since 2012, but there was a small bump in games missed (141.3, up from 139.8).

Concussion rates remained on par with the previous year, with teams recording about seven diagnosed concussions each, including those that didn't result in a player missing a match. 

The average number of matches missed per side with concussions last year (4.2) returned to 2015 levels after jumping to 5.6 in between, as more conservative management was introduced. 

Only one of the 18 clubs elected not to be part of the AFL's concussion audit in 2017. 

Elsewhere, calf injuries returned to historical levels, with an average club incidence rate of 2.1 after climbing to 3.7 five years ago. 

The same was true for the incidence (0.9 injuries per club) and prevalence (7.4 games missed) of leg and foot stress fractures after an unexplained dip the season prior.

Key injury indicators 2007-18

 Injury severity breakdown