INJURY RATES for AFL players in 2012 were down on the year before according to the League's annual injury survey, which was released on Wednesday.

And injury prevalence, best measured as missed games per club per season, was at its lowest level since 2008.

The survey, which was completed for the 21st consecutive year, shows that hamstring injuries over the last two seasons were significantly lower than during the 2006-2010 seasons.

Quad and groin strains were also at lower levels last season although on the flip side, the number of calf strains increased to an average of three per club per season, an increase of 0.9 on the season before.

There were more calf strains in 2012 than in any of the 21 seasons in which the survey has been undertaken.

And there were higher rates of concussions causing missed games in 2012 than the long-term averages, although this is mainly attributable to more conservative diagnosis and management of concussions across the AFL. On average, one player per club missed games in 2012 because of concussion.

Sports across the world are recognizing the potential long-term effects of concussion and like the AFL, are adopting more cautious approaches to player management.

Report authors John Orchard and Hugh Seward said the recurrence rates for all injuries in 2012 was the lowest seen in the history of the sport and marginally down on 2011. All together, there appears to be a long-term downward trend in recurrence rates.

The report states that in 2012, an average club list would expect to have 7.8 players sidelined due to injury in any given week, compared to 8.4 players in 2011.

The survey, which is a key source of data for the AFL and the clubs and heavily shapes their fitness and training, is being published for the first time in the prestigious American Journal of Sports Medicine.

"In the interests of player health and welfare, the injury survey helps to identify the most important areas for further AFL-funded research, with the primary goal of ensuring the game is safe to play and that our players have the best possible treatment and support when returning from any injury," said the AFL's acting general manager of football operations, Gillon McLachlan.

"The AFL will continue to consider and implement rule changes where necessary to improve player safety, not just at the elite level, but across all levels of our game for both adults and children," he said.

Orchard said a key finding was that the long-term trend towards increased injury rates has been arrested over the last two years, although further research and monitoring is needed to determine the effect of the substitute rule on injury rates.

He added that he believed the substitute rule has improved medical management in the AFL and has reduced the pressure on doctors to withdraw injured players from matches in the knowledge there was usually a substitute player available.

Ashley Browne is a senior writer for AFL Media. Follow him on Twitter at @afl_hashbrowne