Games missed due to concussion have continued to increase in the AFL, according to the League's 2015 injury survey, as clubs become more conservative in their management of head injuries.
The annual injury report, which was released on Friday afternoon, shows players missed more than 75 games across the League because of concussion last season, at an average of 4.2 a club.
Download the full 2015 AFL Injury Survey (PDF)
It was a significant spike from the 2014 figures (1.6 games a club) and well up on 10 years ago, when an average of 0.3 games a club were lost each season to concussion.
Football operations manager Mark Evans said the results showed all sections of the injury, including medical officers, coaches and players, had moved to more conservative treatment methods.
The injury survey defines concussion as an instance where a player is required to miss a match.
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The report notes there were fewer new concussions in 2015, compared to the average over the past five years, but more games had been missed.
The AFL revised its concussion management guidelines in 2011, 2013 and again at the start of 2015 to reinforce a more conservative approach to concussion management.
In 2015 the use of a sideline head injury assessment form was introduced to help doctors identify symptoms or conditions that automatically excluded a player from returning to a match.
The AFL said it would present results from the first two years of operation of the form at the International Consensus Conference on Concussion in Sport in Berlin in October.
Meanwhile, serious knee injuries reached a two-year high in 2015, with 16.7 games a club missed because of anterior cruciate ligament injuries across the League (up from 11.1 in 2014 and below the 17.8 in 2013).
An average of 37.4 games were missed per club for all knee injuries (up from 27.6 in 2014 and below 39.5 in 2013).
The 24th annual edition of the injury survey showed clubs lost an average of 156 games to injury in 2015.
Evans said the results would continue to direct the AFL in the work it does with clubs, research boards and other stakeholders to prevent injuries and improve recovery protocols.
"Player health and welfare is a primary concern for the AFL, with continued work every year around ensuring that our rules and our approach to the game works to make the sport as safe as possible within the bounds of a contact sport," Evans said.
The injury results were presented to the League's Medical Officers' Association and all clubs earlier this week.