THE greater rate and ferocity of tackles may be responsible for an increase in shoulder injuries among AFL players, according to the AFL Medical Officers' Association.

Shoulder injuries are the one category stubbornly increasing against another general reduction in injuries, according to the AFL Report on Injuries for 2006, and the association executive officer Dr Hugh Seward admits that the style of game may be contributing to it.

"The severity of the tackles that we've seen is one of those significant factors that is increasing the risk to shoulders," Seward said. "The shoulder (injuries) seems to be steadily increasing," said Dr John Orchard, the compiler of the report. "That's the one we are concerned about becoming a trend."

Figures from Pro-Stats confirm that the number of effective tackles (which either deprive the opponent of possession or tie him up) have gone up by about 1000 over the past four seasons.

This year the AFL has clamped down on high contact and tackles in which a player's arms are pinned and he is thrown heavily to the ground.

The injury report operates one year behind, so any improvement as a result of recent rule changes will not be reflected until next year.

The AFL introduced a 10-metre centre circle to limit ruckmen's run-ups after the injury survey revealed an increase in posterior cruciate ligament injuries among ruckmen. The change has seen the number of PCL injuries sustained in ruck contests reduced to zero in the past two years.

AFL football operations manager Adrian Anderson said he was "unaware of anything in (the 2006 report) that calls for immediate rule change".

Shoulders aside, the report — the 15th annual comprehensive injury survey — reveals that AFL players are getting injured less but missing more games.

Some statistics that reveal the changing nature of the game between 1997 to 2006 include:

■New injuries per team per season decreased from 41.9 in 1997 to 33.9 in 2006.

■Recurrences per team per season decreased from 8.4 (20 per cent) to 4.1 (12 per cent).

■Total incidence decreased from 50.3 to 38.

■Games missed per team per season decreased from 159.2 to 139.5

■Severity (i.e. games missed per injury) increased from 3.8 to 4.1

Looking at specific injuries, shoulders — sprains and dislocations, a/c joint and clavicle) are up, increasing by 60 per cent over the 10 year-period. ACL knee injuries are down over the 10 years but 2006 was the worst season since 2001.

Seward said the reduction in the recurrence rate — hamstring strains were their highest since 1999, for example, but recurrence was the lowest ever recorded — might reflect changes in management of the injury.

"I think we're being more conservative about managing them, and taking a bit longer, to avoid the recurrence," Seward said.

The other factor influencing the number of games missed was the high number of ACL injuries last season. ACL injuries tend to occur at the start of the season and involve a year out of the game.

The trend for clubs with no chance of making the finals bringing forward what has normally been post-season surgery also meant more missed games.

In 2006, 16 players missed the final round with shoulder injuries, most opting for early surgery. The figure was 10 in each of the previous two years, and before that had averaged six.