Shoulder Dislocations: A new cause for concern in School Rugby – Therese Leahy

In September of this year, the first Irish school Rugby season report was published by the IRIS (Irish Rugby Injury Surveillance) project in collaboration with the IRFU. The report published injury data collected from 305 School Senior Cup Rugby players (17-19years) from 11 teams across one season (2018 to 2019).

Injuries were defined as per the World Rugby consensus statement (Fuller et al, 20017) and only time loss injuries that required greater than 24hrs absence from Rugby activities were analysed. Match injury data were expressed as per 1,000 playing hours and the overall injury incidence rate reported was 67.8 per 1,000 player hours. This equates to approximately one injury occurring per Senior Cup School game or in terms of injury risk, ‘a Senior Cup player would sustain an injury every 13 matches’. Although the overall injury incidence reported was higher than previously reported for school Rugby cohorts­, this report focussed solely on the most elite level of Irish school Rugby competition whereas the level of play is not apparent in other school Rugby reports (RFU YRISP Report). A study by Barden & Stokes (2018) demonstrated the differences in incidence rates between their regular school competitions (34/1000hrs) and their elite competition (77/1000hrs) for players of the same age group (16-19years). Secondly, our findings are based just on one season, further analysis over a number of seasons is warranted to identify trends.

A concerning and perhaps unexpected finding from this report was the high rate of shoulder injuries reported in this cohort. 26% of all injuries (17.4 per 1,000 player hours) involved the shoulder. Shoulder dislocations/subluxations represented the most common shoulder injury diagnosis accounting for 7.2 per 1,000 player hours and were also the most common cause of severe injury. Severe injuries are classified as injuries that required greater than 28days absence. This rate is significantly higher than what was reported for the IRIS Men’s AIL season report where shoulder dislocations represented 0.9 per 1,000 player hours. Why is there such a difference in rates between groups? Perhaps the older players demonstrate greater stability around the joint? Perhaps they are more skilled at tackling therefore less likely to expose the arm to vulnerable positions?  Further analysis of the school data indicated that the ‘tackler’ was most at risk of sustaining a shoulder dislocation/subluxation with 67% of these injuries occurring to players when ‘tackling’ whereas just 17% occurred to the ball carrier. When tackling a player, the arm is generally in the vulnerable position of 90 degrees abduction and external rotation, the force of the opposing player pushing the arm back behind potentially causing an anterior dislocation of the humeral head. Shoulder dislocation can also commonly occur by falling onto an outstretched arm such as scoring a try or by falling onto a flexed elbow. Shoulder dislocation is a significant injury for a young player and often results in surgery in order to stabilise the joint. Many players can suffer from repeated instability events following a shoulder dislocation which may cause further injury to the shoulder joint/capsule itself (Kawasaki et al, 2014).  It is not yet apparent as to why the rate of shoulder dislocations in this group are high, perhaps the physical immaturity of youth players coupled with poor strength/rehabilitation practices may be increasing their risk of injury? Some authors (Montgomery et al, 2019) have proposed that repeated stresses in certain tackle positions may be contributing to increased laxity in the joint? Hypermobility or hyperlaxity may be an issue in teenage players?

In order to reduce injury risk for a particular injury one must fully understand the exact mechanisms of occurrence along with any potential risk factors. Further analysis of longitudinal data is ongoing currently within the IRIS project with the hope of gaining a greater understanding around the mechanisms and risk factors of shoulder dislocations within this cohort.


  1. Fuller, C.W., Molloy, M. G., Bagate, C., Bahr, R., Brooks, J. H., Donson, H., et al. (2007). Consensus statement on injury definitions and data collection procedures for studies of injuries in rugby union. British Journal of Sports Medicine. 41(5) 328-331.
  2. F.U. Youth Rugby Injury Surveillance Project (YRISP) Season Report 2017-2018. University of Bath. 2019.
  3. Barden, C., & Stokes, K. (2018). Epidemiology of injury in elite English schoolboy rugby union: A 3-year study comparing different competitions. Journal of Athletic Training, 53(5), 514e520.
  4. Irish Rugby Injury Surveillance (IRIS) Project. All-Ireland League Amateur Club Rugby 2018-2019 Season Report. IRFU. University of Limerick. 2019.
  5. Montgomery, C et al. 2019. A systematic video analysis of the mechanisms of shoulder dislocations in professional Rugby union. Journal of Science and Medicine in Sport, Volume 21, S50
Tagged with: