Interim evaluation of the effect of a new scrum law on neck and back injuries in rugby union.

BACKGROUND: In January 2007 the International Rugby Board implemented a new law for scrum engagement aimed at improving player welfare by reducing impact force and scrum collapses. In New Zealand the new law was included in RugbySmart, an annual compulsory workshop for coaches and referees.

OBJECTIVE: To determine the effect of the new law on scrum-related moderate to serious neck and back injury claims in 2007.

METHODS: Claims filed with the Accident Compensation Corporation (the provider of no-fault injury compensation and rehabilitation in New Zealand) were combined with numbers of registered players to estimate moderate to serious scrum-related claims for players who take part in scrums (forwards). Poisson linear regression was used to compare the observed claims per 100 000 forwards for 2007 with the rate predicted from data for 2002-6.

RESULTS: The observed and predicted claims per 100 000 forwards were 52 and 76, respectively (rate ratio 0.69; 90% CI 0.42 to 1.12). The likelihoods of substantial benefit (rate ratio <0.90) and harm (rate ratio >1.1) attributable to the scrum law were 82% and 5%, respectively.

CONCLUSION: The decline in scrum-related injury claims is consistent with a beneficial effect of the new scrum law in the first year of its implementation. Another year of monitoring should provide more evidence for the efficacy of the new law.