UL and IRFU research reveals lowering of tackle height in rugby has led to sharp decline in concussion and injury rates

A major new study from researchers at University of Limerick has shown a sharp decline in concussion and injury rates amongst rugby players since the Irish Rugby Football Union (IRFU) lowered the legal tackle height across the amateur game.

The study reports on data collected by the Irish Rugby Injury Surveillance (IRIS) project, a collaboration between UL and the IRFU, and is the first study to longitudinally explore the impact of this rule change on both the men’s and women’s amateur game and the schoolboy game.

It is one of the most comprehensive studies to date into how tackle height affects injury risk in rugby union.

While other studies have indicated the lowering of the legal tackle height can change player behaviour, this is the first study to report positive findings on concussion and overall injury rates in amateur players, marking a significant development in player safety.

The findings reveal a decrease of 38% in tackle-event concussion rates in men’s community rugby, alongside an 18% reduction in overall match injuries.

In the women’s game, the reductions were even more pronounced, with tackle-event concussion rates falling by 63% and overall injuries decreasing by 30%.

While overall injury rates decreased by 19% in schoolboy rugby, there was no significant change in concussion rates.

The findings are particularly important given that the tackle accounts for the majority of injuries in rugby with concussion being a key issue across all levels of the game.

Researchers analysed data across five seasons before the tackle height was lowered from the armpit to the base of the sternum in June 2023 and compared this with data across the two trial seasons to 2025.

86,000 hours of match play were analysed as part of this study, with more than 3,700 recorded injuries, by trained recorders or medics, examined across 239 adult men’s, adult women’s and schoolboy teams.

The research, which was led by Principal Investigators Professor Tom Comyns and Professor Ian Kenny with lead authors Dr Kilian Bibby and Dr Lauren Guilfoyle, was published in the Journal of Science and Medicine in Sport.

Professor Tom Comyns, Principal Investigator at UL’s Sport and Human Performance Research Centre and Professor of Human Movement Science at UL’s Department of Physical Education and Sports Sciences (PESS), said: “The research from IRIS has impacted policy and practice within the IRFU and ultimately player health and wellbeing. IRIS has allowed for robust longitudinal analysis of the tackle height law change and these findings are continuing to impact decision-making within the game.”

Professor Comyns added: “More research is needed and underway to further assess the impact of the tackle height law change and to enhance our understanding of the impact of the change in the schoolboy game.”

Professor Ian Kenny, Principal Investigator at UL’s Sport and Human Performance Research Centre and Professor of Biomechanics at PESS in UL, said: "Longitudinal data from schools and amateur clubs allow us to continually monitor injury trends from youth to adult levels. This insight is invaluable in shaping prevention programmes and education initiatives for players and coaches.

“Stemming from a game law change this is the first study to report very positive findings on concussion and overall injury rates, benefitting the broad base of the amateur playing population.”

The study represents a sustained programme of collaborative research between UL and the IRFU, focused on generating high-quality evidence to improve player safety in the community game.

IRFU Medical Director, Professor Rod McLoughlin said: “The IRFU Tackle Behaviours Trial has been a successful strategy for improving player welfare and performance. Thanks to the IRIS project, we are one of few Unions worldwide with the ability to compare injury data before the tackle height was lowered and after.

“Through our ongoing collaboration with University of Limerick we will continue ongoing research in this area to strengthen the evidence. We are also gaining insights into the nature of behaviour change that occurred at all levels of the game, through video analysis in conjunction with Trinity College Dublin, and this provides us with a greater understanding of what drove the results of this trial.”

Launched in 2016, the IRIS project is the first long-term injury surveillance research project within amateur rugby union in Ireland. Over a 10-year period, trained injury recorders have documented the incidence, type, nature and severity of both match and training injuries occurring across the amateur game in Ireland.

Research from the project has aided in the development and implementation of evidence-based injury prevention strategies that aim to minimise injury risk and enhance player welfare. Data from the project has directly informed the IRFU’s ENGAGE Readiness and Robustness Programme, breast health awareness training, and playing surface injury risk.

Professor Ian Kenny concluded: “Large scale longitudinal studies of this type are not common. In 2016, we embarked on this project with the IRFU to design a robust online injury data collection system, and over the past 10 years the project has included 13 multidisciplinary professors, 10 PhD students, a post-doctoral researcher, a research assistant, nine master’s students, over 80 injury recorders and several collaborating research funders who have contributed to this study.”