Background Rugby union is characterised by frequent and dynamic collisions. Players typically aim to avoid direct contact to the head due to its potential for serious head injury. However, head collisions still occur – possibly due to players either being unaware of the impending contact, or executing poor technique during, or prior to contact.

Objective Video analysis of contact technique and head collisions in rugby union.

Design Retrospective video analysis.

Setting Professional rugby union players.

Participants Video footage of 211 contact events.

Assessment of Risk Factors Contact characteristics and contact technique for attackers and defenders during head collisions. Attackers and defenders were categorized into higher and lower risk roles depending on which had the higher potential for injury.

Main Outcome Measurements Contact descriptors and contact proficiency scores

Results Eighty-four percent of head collisions occurred during the tackle, followed by aerial collisions (10%), and rucks (6%). Eighty-two percent of collisions occurred with an opponent. Higher risk players were aware of the impending contact 70% of the time. Mean contact proficiency score (arbitrary units; AU) in front-on tackled ball-carriers was 6.4±3.2 and 8.2±3.2 AU for ball carriers at higher and lower injury risk, respectively (p≤0.01, effect size=0.6, moderate). The mean contact proficiency score in front-on tackle tacklers was 9.8±3.7 and 9.2±3.5 AU for tacklers at higher and lower injury risk, respectively (p>0.05, ES=0.2, small).

Conclusions The tackle event accounted for most head collisions. Most players were aware of the impending contact. Higher injury risk ball-carriers in front-on tackles scored relatively low in proficiency compared to lower injury risk ball-carriers. For contact proficiency score, each technical criterion was equally weighted. Failure to execute specific criteria (e.g. head up and forward) may increase the risk of head collisions compared to other criteria (e.g. fending). Future studies on contact techniques should weight technical criteria more appropriately.