Decreased incidence of knee posterior cruciate ligament injury in Australian Football League after ruck rule change.
OBJECTIVE
To assess whether a rule change introduced in the Australian Football League (AFL) before the start of the 2005 season, to limit the run-up of ruckmen at the centre bounce, has been successful in reducing the incidence of knee posterior cruciate ligament (PCL) injuries.


METHODS
Cohort study with historical control.


METHODS
The AFL competition from 1992 to 2008 inclusive.


METHODS
The presence of a rule change (four seasons) compared with the previous 13 seasons (divided into two eras of seven and six seasons).


METHODS
Occurrence of knee PCL injury during a regular season or finals match, both from all causes and specifically from centre bounce ruck collision mechanisms.


RESULTS
From 1992 to 1998 there were 11.0 PCL injuries per 10,000 player-hours, with 0.8 ruck injuries per 10,000 centre bounces. From 1999 to 2004, the rates increased to 12.9 per 10,000 player-hours and 5.6 ruck injuries per 10,000 centre bounces (p<0.01). The rates reduced to 5.9 PCL injuries per 10,000 player-hours and 0.9 ruck injuries per 10,000 centre bounces in the period 2005-2008 following the rule change (p<0.01). There was a lower relative risk in 2005-2008 than in 1999-2004 of incurring a centre bounce ruck PCL injury (0.16 (95% CI 0.04 to 0.69)) or of sustaining any PCL injury (0.45 (95% CI 0.28 to 0.75)).


CONCLUSIONS
A rule change in the AFL to limit the run-up of ruckmen at the centre bounce has successfully reduced the rate of PCL injuries with this mechanism, with the total incidence of PCL injuries also falling.
Orchard
J W
JW
Sports Medicine, School of Public Health, University of Sydney, Sydney, NSW, Australia. jorchard@med.usyd.edu.au
Seward
H
H
D001315:Australia / Q000453:epidemiology; D015331:Cohort Studies; D005538:Football / Q000293:injuries* / Q000331:legislation & jurisprudence; D006801:Humans; D015994:Incidence; D007718:Knee Injuries / Q000453:epidemiology*; D016119:Posterior Cruciate Ligament / Q000293:injuries*; D012307:Risk Factors