Rainfall, evaporation and the risk of non-contact anterior cruciate ligament injury in the Australian Football League

Med J Aust. 1999 Apr 5;170(7):304-6. doi: 10.5694/j.1326-5377.1999.tb127782.x.


Objective: To determine if weather conditions affect the risk of anterior cruciate ligament (ACL) tear in Australian Football.

Design: Prospective observational analytic study of football matches.

Setting: The Australian Football League (AFL), a professional competition.

Participants: All players in 2280 matches from 1992-1998.

Main outcome measures: Surgically-proven ACL injury, not involving a direct contact mechanism, during a match; rainfall; water evaporation.

Results: 59 ACL injuries not involving direct contact occurred during the study period, more commonly in cities north of Melbourne (chi 2 = 17.0; df = 1; P < 0.001). Senior grade matches (relative risk [RR], 3.03; 95% confidence interval [CI], 1.52-6.03), high water evaporation in the month before the match (RR, 2.80; 95% CI, 1.53-5.10) and low rainfall in the year before the match (RR, 1.93; 95% CI, 1.12-3.34) were significantly associated with these injuries.

Conclusion: Low water evaporation and high rainfall significantly lower the risk of ACL injuries in AFL footballers. The likely mechanism is a softening of the ground, which lowers shoe-surface traction. Consistent extra watering and covering of grounds during periods of high water evaporation may lower the rate of ACL injuries.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anterior Cruciate Ligament Injuries*
  • Australia / epidemiology
  • Humans
  • Logistic Models
  • Prospective Studies
  • Rain*
  • Risk Factors
  • Seasons
  • Shoes
  • Soccer / injuries*
  • Soil
  • Surface Properties
  • Wounds and Injuries / epidemiology
  • Wounds and Injuries / etiology
  • Wounds and Injuries / surgery


  • Soil