Objectives Most concussions in rugby union occur during tackles. We investigated whether legislating to lower maximum tackle height would change tackle behaviour, and reduce concussion incidence rate.
Methods In a single group intervention, 12 elite men’s teams played in two competitions during the 2019/2020 season. The Championship (control, 90 games) retained standard Laws of Rugby for the tackle; the Championship Cup (intervention, 36 games) used revised laws—the maximum tackle height was lowered from the line of the shoulders on the ball carrier to the line of the armpits. Videos of tackles were analysed for ball carrier and tackler behaviour. Injury data were collected using standardised methods.
Results In the intervention setting, there was a significantly lower proportion of tackles; (1) in which ball carriers (rate ratio (RR) 0.83, 95% CI 0.79 to 0.86) and tacklers (RR 0.80, 95% CI 0.76 to 0.84) were upright, (2) in which the tackler’s initial contact was to the ball carrier’s head or neck (RR 0.70, 95% CI 0.58 to 0.84) and (3) in which initial contact was above the line of the ball carrier’s armpit (RR 0.84, 95% CI 0.80 to 0.88). Concussion incidence rate did not differ between conditions (RR 1.31, 95% CI 0.85 to 2.01). Unexpectedly, compared with the control setting, tacklers in the intervention setting were themselves concussed at a higher rate as measured by; (1) incidence (RR 1.90, 95% CI 1.05 to 3.45) and (2) concussions per 1000 tackles (2.09, 95% CI 1.15 to 3.80) than in the control setting.
Conclusions Legislating to lower the height of the tackle meant that tacklers made contact with the ball carrier’s head and neck 30% less often. This did not influence concussion incidence rates. Tacklers in the intervention setting—who were aiming to tackle lower—suffered more concussions than did tacklers in the control setting.
- injury prevention
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Twitter @drkeithstokes, @drsimonkemp
Contributors The study was designed by KAS, SK and DR. Data collection was carried out by KAS, SR, LH and DL. Data analysis was carried out by KAS, DL and RT. The first draft of the manuscript was prepared by KAS. All authors contributed to revisions of the manuscript and approved the submitted version.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests KAS, DL, LH and SK are employees of the Rugby Football Union, which is the governing body for Rugby Union in England. RT is employed by World Rugby, which is the governing body for the sport of Rugby Union and responsible for law changes in the sport.
Patient consent for publication Not required.
Ethics approval Ethics approval for all injury data (REACH: EP 17/18 170) and specific concussion data (REACH: EP 16/17 286) was given by the University of Bath.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement No data are available.
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