Objective: To investigate whether the movement of the playing season from winter to summer would alter the risk of injury to players taking part in first team European professional rugby league.
METHODS: The study design was a historical cohort design comparing winter and summer seasons in first team European rugby league, which recorded injuries received by players during match play. Each injury was classified according to site, type, player position, activity at the time of injury, and time off as a result of injury.
RESULTS: The risk of injury when playing summer rugby league was higher than when playing winter rugby league (relative risk = 1.67 (95% confidence interval 1.18 to 2.17)). Both forwards (1.08 (0.28 to 1.88)) and backs (2.36 (2.03 to 2.69)) experienced an increased risk of injury.
CONCLUSIONS: Summer rugby may have resulted in a shift of injury risk factors as exhibited by a change in injury patterns. This may be due to playing conditions, but there were also some law changes. Changes in playing style, team actics, player equipment, fitness preparation, and the reduced preseason break may also have had confounding effects on injury risk.