four injurious rucks (75%), the concussed player was acting defensively either in the capacity of ‘support’ (n=2) or as the ‘jackal’ (n=1; table 5). The role of non-injured players was distributed as follows: 43% were ‘support attack’, 39% ‘support defence’, 10% ‘jackal’ and 8% ‘ball-carrier’ (n=61). In three of the four concussive rucks (75%), the attacking team was ‘clearing the ruck’. In non-injury rucks, the attack was ‘clearing the ruck’ 52% of the time and ‘protecting the ball’ 48% (n=61) of the time. The defensive team were ‘competing for the ball’ in 75% of injurious rucks. Similarly, in non-injury rucks, the defensive team was ‘competing for the ball’ on the majority (70%, n=61) of occasions. The attack maintained possession in all concussive rucks and in 90% of non-injury rucks.
Aerial collision for injury and non-injury events
In the injurious aerial collision, both players involved were unaware of the impending contact (n=1; table 5). With regard to the speed of player(s), both players involved in injurious collision were moving at a pace classified as ‘fast’ (the injured player was the defensive player). In the matched non-injurious aerial collisions, all the defenders were moving at a pace classified as ‘moderate’ and the attackers were observed as ‘slow’ on all the occasions. Impact was ‘high’ in the injury event versus ‘low’ in all non-injury events. In the inciting event, the concussed player failed to land on (his) feet in a stable manner, whereas in all non-injury events this was maintained (n=3). The ‘attacker was higher than defender’ in the majority of injury (100%, n=1) and non-injury (67%, n=3) events. In the inciting event, the concussed player failed to land on (his) feet in a stable manner, whereas in all non-injury events this was maintained (n=3).
Insight into the injury mechanism of concussion in youth rugby
This is the first study to describe the global and local injury mechanisms of concussion and compares it with a representative and matched non-injury sample in youth rugby, which is an important aspect in formulating effective injury prevention strategies.5 ,6 Over a 3-year period, 18 concussions were recorded, and only 10 were available for analysis due to the poor quality of the video footage. This small sample of concussion events over 3 years highlights the challenge with conducting a study of this nature. Owing to the small sample size, the study should be considered preliminary, and therefore any conclusive remarks are difficult to make. That said, the study provides insight into the injury mechanism of concussion in youth rugby, where otherwise data would not exist, and the data can be interpreted in the context of the current injury prevention strategies for concussion.
Situational factors associated with concussion
In describing the situational factors associated with concussion, all injuries occurred as a result of contact ‘with opponent’. The ability to tolerate and engage in frequent physical contact with the opponent is a prerequisite for participation in rugby. Therefore, it is not surprising that contact with an opponent is a major feature in the series of events leading to concussion. For the concussive events analysed, the players were unaware of the impending contact. This finding is in line with Garraway et al23 who found that tackle injury was more likely to occur when the player was unaware of opponents’ movements. An explanation for this is that a player can sustain far greater forces without injury if the cervical muscles are tensed, which occurs when the athlete anticipates the collision. It is postulated that activating the neck and posterior shoulder muscles reduces the risk of concussion by mobilising the head, thereby decreasing the resultant acceleration of impact to the head.24
Coaching players to increase awareness and anticipation of ensuing contact may therefore be a worthwhile preventative measure for concussion.24
Match period and concussion
The majority of concussive events took place in the fourth quarter. This finding is consistent with previous lite