Injury Rates in Rugby League Football: Impact of Change in Playing Season

Background In 1996, the professional rugby league moved its playing season from the autumn and winter months to the spring and summer. Purpose To determine whether the change in playing season altered the risk of player injury. Study Design Prospectively collected data comparing two cohorts. Methods Injuries incurred by all players in one club during match play were recorded over 9 seasons: 4 winter (138 games) and 5 summer (144 games). Each injury was classified according to site, type, player position, activity at the time of injury, and number of games missed as a result of injury. Results The total exposure time during this study was 4876 player-hours (winter, 2386, summer, 2490). The relative risk of injury doubled after the move from winter to summer. Winter rugby accounted for 72 injuries, and summer rugby, for 150 injuries. Conclusions Risk of injury to players in a professional rugby league club greatly increased as a result of changing the playing calendar, possibly as a result of environmental factors. However, other factors, such as increased conditioning levels, which have been a direct consequence of players moving to full-time professionalism, may have increased injury potential.