‘stationary’ or ‘slow’, suggesting that difference in speed is a risk factor for concussion. Speed differences on contact during rugby have been noted before as a risk factor for injury in rugby.16 ,23 That said, the speed difference between players on contact, as a risk factor for injury, should not be interpreted in isolation.15 ,31
In the majority of injuries to the tackler, leg drive by the tackler was observed to be ‘absent’. BokSmart recommendations on safe tackling techniques emphasise the need for a player to maintain leg drive after contact.16 This particular technical point also increases the probability of tackle success.19
Ruck contact techniques and concussion
Rucks contributed the second largest proportion of concussions. In three of the four concussive rucks, the team on attack was ‘clearing the ruck’ while the defensive team was observed to be ‘competing for the ball’. These situations are characterised by players darting or charging into a mass of players, exposing players to potential risk of injury.32 Considering the observation that three of the four players injured in the ruck were acting in defence (2 as ‘support’ and 1 as ‘the jackal’), it seems that players fulfilling a defensive role in the ruck at the time the attack are clearing are more susceptible to concussive impacts. Additionally, all three of the players were unaware of the impending contact at the time of their injuries. It may therefore be useful to incorporate a coaching emphasis on ‘maintaining awareness’ for players engaging defensively during a ruck.
Strengths, limitations and implications
As mentioned earlier, the study is limited by its small sample size, and this ultimately restricted the statistical analyses. That said, the data are important as 3 years of concussion data in youth rugby are reported, and should be seen as setting the foundation for a longitudinal study with more injury and non-injury events. Future concussion research and application may benefit more from a refined video analysis coding system, similar to Hutchison et al's12 checklist in ice hockey.
This study represents an attempt to move beyond epidemiological studies by establishing the aetiology and injury mechanism underlying youth concussion and, in doing so, progressing the process of injury prevention. On the basis of the findings, training interventions aimed at improving peripheral vision, targeted conditioning programmes to reduce the effects of fatigue and emphasising safe and effective playing techniques should be structured with the goal of reducing the risk of concussion. While an elimination of concussion in rugby is unlikely, continued research in this area is essential to providing a foundation for the development of effective education, evaluation and prevention strategies.
The authors would like to thank the medical staff at all of these tournaments for their invaluable assistance with the injury data collection: all the nurses and paramedic staff at each of the tournaments as well as the tournament doctors: Dr Deon Van Tonder, Dr Malebo Mokotedi, Dr Andrea Burmeister, Dr Patho Cele, Dr Charles Smit, Dr Liz Leuenberger, Dr Ferdi Adams and Dr Viaan Vellerman. They would also like to thank SARU's BokSmart National Rugby Safety Programme and Medical Department for commissioning this injury surveillance project. The authors would also like to express their gratitude to the National Research Foundation Post-Doctoral Fellowship for their support.
Contributors SH was responsible for write-up of the manuscript and study conceptualisation. SO was responsible for data collection. NB and SMF assisted with data collection and data analyses. CR and WV set up injury data collection and access to video. JCB collected injury data. ML assisted in all aspects. All the authors edited the manuscript.
Competing interests None declared.
Ethics approval This study was granted ethical approval by the University of Cape Town Health Science Human Research Ethics Committee. UCT Human Research Ethics Committee (injury database HREC Ref: 438/2011; video database HREC Ref