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
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation