Does reducing the height of the tackle through law change in elite men’s rugby union (The Championship, England) reduce the incidence of concussion? A controlled study in 126 games

Abstract

ObjectivesMost 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.MethodsIn 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.ResultsIn 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.ConclusionsLegislating 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.

Force experienced by the head during heading is influenced more by speed than the mechanical properties of the football

“…However, rule changes can lead to unintended consequences and increased injury rates, and thus, head impact exposure and injury monitoring would be essential. 32 Additionally, more research is needed to understand phase of play-specific football speeds at which headers occur. A new goal kick law trial where the ball is in play once kicked and can be played before leaving the penalty area was introduced in 2019/20.…”

Ethics and injury risk in World Rugby and England Rugby tackle-height trial

“…Adam John White , 1,2 Joe Piggin , 3 John Batten, 4 Gary Turner, 5 Alan Pearce, 6 Rachael Bullingham, 7 Eric Anderson 8…”

“…8 This is particularly concerning given that 'the majority of players felt that reducing tackle height would result in more, rather than less, concussions'. 7…”

“…The impact of this trial was greatest on the tackler, whereby '…concussion incidence rates for tacklers were 6.9 per 1000 hours in the control and 13.2 per 1000 hours in the intervention period'. 7 Therefore, the trial increased the risk of injury in the form of mild traumatic brain injuries to the participants within Championship Rugby.…”

“…Indeed, the authors have reported this research as an 'intervention' study. 7 Thus, it becomes difficult to accept any assertion that tries to separate the trial from the research, a common strategy used to erode the nature of participant informed consent in trials. 9 The ethical approval cited by the researchers refers to observational injury surveillance and does not acknowledge any intervention (ie, the change to the laws of the game).…”