An Investigation of Potential Factors Leading to Shoulder Injury in Adolescent Rugby Union Players: A Retrospective Cohort Study

Objectives: To investigate the association between potential factors that may lead to shoulder injury in adolescent male rugby union players.

Methods: A self-administered questionnaire consisting of 10 standardised questions was used to investigate the incidence of shoulder injury in adolescent male rugby union players. Participants had previously partaken in a study by Rowland and colleagues in 2014 investigating shoulder range of motion, strength and generalised joint hypermobility. Data from the previous and current study was correlated in order to determine the relationship between the aforementioned variables and shoulder stability.

Results: Twenty three (23) participants completed the questionnaire with 9 participants (39%) reporting a shoulder injury. No statistically significant association was found between shoulder injury and generalised joint hypermobility (p=0.32), average shoulder range of motion (p=0.38), body mass index (p=0.60) or hand dominance (p=0.53). A statistically significant association was observed between shoulder injury and shoulder muscle strength (p=0.04). Similarly, a statistically significant association was found between left shoulder flexion strength (p=0.03), right shoulder flexion (p=0.03), left shoulder abduction (p=0.03) and right shoulder
internal rotation at 90 degrees abduction (p=0.008).

Conclusions: Reduced strength of the shoulder musculature appears to be associated with an increased risk of sustaining a shoulder injury in adolescent male rugby union players. However, it is inconclusive if overall generalised joint hypermobility along with increased active shoulder ranges of motion are associated with
shoulder injury. Further investigations are required to determine if muscle strengthening programs are effective in reducing shoulder injuries.