720 FO50 – Breaking down the tackle: tackle characteristics associated with concussion in female varsity rugby union

Background Concussion rates associated with the tackle in rugby union (hereafter, rugby) are amongst the highest in collision and female sports. Early evidence indicates that tackle and head impact mechanisms differ between males and females. To improve female player welfare, female-specific evaluations are needed to inform optimal safety recommendations. Objective To evaluate the association between tackle characteristics and concussion in female rugby. Design Case-control video analysis study. Setting Female university rugby. Participants Anonymous match footage from a Canadian university rugby competition (2017–2019; 48 matches). Assessment of Risk Factors Every case (concussive tackle) was matched by team and game to six randomly selected control (non-concussive) tackles. Bivariate penalized maximum likelihood logistic regression analyses were used to compute odds ratios (OR) 95% confidence intervals (95% CI) between exposures (tackle characteristics) and outcome (concussion). Tackle characteristics head contact intensity (4-point ordinal scale indicating head contact intensity), tackle type, pre-contact and contact body position, pre-contact head position, speed, acceleration were chosen a-priori. Main Outcome Measurement Tackle-related concussion. Results Forty-six concussions (25 ball-carrier, 21 tackler) were identified from 45 tackle events. Head contact intensity of 3–4/4 (OR: 48.5; 95% CI: 12.9–182.7), illegal tackle type (OR: 13.3; 95% CI: 1.9–93.7), low pre-contact body position (OR: 3.3; 95% CI: 1.0–10.6), and away head position (OR: 4.0; 95% CI: 1.1–14.3) were associated with ball-carrier concussion. Three tacklers in the event (OR: 7.0; 95% CI: 1.5–33.7), head contact intensity of 3–4/4 (OR: 30.6; 95% CI: 7.0–133.5), and down head position (OR: 3.0; 95% CI: 1.2–7.5) were associated with tackler concussion. Conclusions The identified variables (i.e., head impact intensity, head/body position, # tacklers in event) in the present study can be used to inform targeted injury prevention strategies (e.g., law change, tackle training program) aimed at reducing concussion in female rugby. Strategies aiming to minimize head contact are needed.