Tackle characteristics associated with concussion in elite men's rugby union: unpicking the differences between tacklers and ball-carriers.

Objective: To identify characteristics of tackling, of being tackled and interactions between tackle characteristics that are associated with concussion.

Methods: A case-control study in male professional rugby union players in England over five seasons (2016/2017 to 2020/2021) analysed characteristics of tackles that led to a clinically diagnosed concussion (cases), and a control group of tackles that did not result in a concussion. ORs were plotted against the overall frequency of each tackle characteristic.

Results: 231 tackles resulting in concussions (tackler 178, 77%; ball-carrier 53, 23%), alongside 9963 control tackles, were analysed. For tacklers, 'head to torso' ( OR 6.5 ) had relatively low odds of concussion compared with 'no head contact'. 'Head to knee' had the highest odds of concussion ( 155.8 ), but 'head to hip' occurred more frequently and had the highest number of concussions per 1000 tackles (3.1/1000 tackles). For ball-carriers, 'head to head' contact had the highest odds of concussion ( 104.3 ). When 'tackler body position' was 'upright', the odds of concussion to the tackler were significantly higher when contacting the ball-carrier's 'head and neck' versus their 'torso' ( 23.7 ).

Conclusions: Lower tackles reduce the chances of concussion to ball-carriers. The influence of tackle height on concussion to tacklers is more nuanced, but the chances are relatively low when contact is made with the ball-carrier's torso. These findings support ongoing implementation of strategies to reduce concussion risk by lowering tackle height to target the torso.