1 player was using both a mouthguard and a scrum cap.
Only one of the injurious tackles was ‘completed’ (n=1 of the 5), as opposed to 53% of non-injury tackles (n=10 of the 19). From a tackler perspective, 60% of concussive tackles were ‘unsuccessful’ (n=3 of the 5), and 11 of the 19 non-injury tackles were ‘successful’ (58%).
Over the 3 years, 18 concussions were recorded, representing 11% of all injuries and translating into an incidence rate of 5.8 concussions per 1000 player hours (95% CI 3.1 to 8.5). There was no significant difference in incidence rate between 2011 and 2012 with a rate of 3.8 (95% CI 0.1 to 7.5) and 3.9 (95% CI 0.1 to 7.8) concussions per 1000 player hours, respectively. In 2013, the incidence rate increased to 9.52 concussions per 1000 player hours (95% CI 3.6 to 15.4).
A total of 10 concussions were analysed, of which 5 occurred during the tackle (4 to the tackler and 1 to the ball-carrier), 4 during the ruck and 1 during an aerial collision (table 3). All 10 concussions analysed occurred after contact with an opponent. In terms of anticipating contact, 60% (n=10) of the players were unaware of the impending contact. Fifty per cent of the injured players were forwards (2 flankers, 2 hookers and 1 lock, respectively) and 50% were backline players (2 fullbacks, 2 centres and 1 wing, respectively). In 50% (n=10) of the cases, the injured player's team was losing, 20% drawing and 30% winning. On-field medical attention was received immediately after the injury event by 9 of the 10 players. One player was attended to during half time and subsequently removed from the game.
The ‘up and forward’ head position represented 40% (n=10) of all precontact head positions while 30% of players assumed a ‘down’ head position and 20% an ‘away’ position (1 precontact head position was unidentifiable). In head position on contact, 30% of players were observed displaying a ‘down’ position, 20% the ‘up and forward’ position and 20% the ‘away’ position (3 head position on contact events were unidentifiable, n=10). Contact to the ‘head/face’ of the concussed player was noted in all injury events (n=10). In contrast, the body region of the other player most commonly contacted in concussion events was ‘hips and below’ (50%, n=10).
Seventy per cent of concussions occurred as a result of contact to the ‘anterior’ side of the head, with 20% as a result of contact to the ‘posterior’ side of the head (1 body location unidentifiable, n=10). Acceleration of the head was found to occur within the ‘sagittal’ plane 50% of the time. Only 20% of the concussed players were moving at a ‘fast’ speed preceding the concussion. The majority (70%, n=10) of injured players were either ‘stationary’ (50%) or moving at a pace categorised as ‘slow’ (20%). In contrast, the ‘other’ players involved in the inciting event were moving at a ‘moderate’ (60%, n=10) and ‘fast’ (40%) pace.
Injury and non-injury playing situations
Sixty per cent (n=10) of injury events occurred in the ‘fourth quarter’, whereas non-injury events were more evenly distributed between quarters with 45%, 24%, 19% and 12% occurring in the first, second, third and fourth quarters, respectively (n=83). Two of the four injurious rucks (50%) occurred in the ‘defensive in-goal area/try-line to defensive 22 m’, whereas the majority (53%, n=60) of non-injury rucks occurred in the ‘defensive half-way line to defensive 22 m’. All (n=4) aerial collision situations (injury and non-injury) occurred within the ‘ball-carriers 22 m to the half-way line’. Two injurious tackles occurred within the ‘ball-carrier's 22 m to the half way line’ and two were within the ‘defensive half-way line to defensive 22 m’, with the remaining one occurring in the ‘defensive in-goal area/try-line to defensive 22 m’ (n=5). The majority (42%) of non-injury tackles occurred in the ‘defensive half-way line to defensive 22 m’ (n=19).
Tackle descriptors for injury and non-injury events
The body position of the tackler in injury events was distributed as follows: 20% ‘upright’, 20% ‘medium’, 20% ‘low’, 20% ‘upright to l