Epidemiology, clinical characteristics, and associated risk factors for injury among university student rugby players

Abstract

Background: Specific features of university student rugby players and the tournaments they compete in may involve epidemiology, clinical characteristics, and associated risk factors that differ from other populations. To date, this has not been studied. Aim of the study: To determine the epidemiology, clinical characteristics of and the associated risk factors for rugby-related injuries in university student rugby players. Design: Prospective cohort study Setting: Rugby teams (Young Guns [YG] and Varsity Cup [VC] representing the University of Pretoria (UP) in the Varsity Rugby tournament. Participants: 171 male university student rugby players. Methods: A prospective cohort study was conducted over two consecutive rugby seasons (2018/19 and 2019/20). Male student rugby players at UP that were included in the YG and VC squads, were followed over a total period of 35 weeks (2018/19: 18 weeks, 2019/20: 17 weeks). The two squads were comprised of a total of 179 players over the two-year period, where 171 players gave consent for study participation. Baseline data were collected at the beginning of pre-season preparations. These included player’s age, playing position and highest level of representation, and completion of injury history and medical history questionnaires. Medical staff affiliated with the teams recorded all training and match time-loss injuries during preseason and in-competition period. Data are reported as the incidence (injuries per 1 000 player-hours: 95% CI) of time-loss rugby-related injuries, injured player proportion (%), frequency (% of injuries) of injury characteristics and injury severity grade (time loss) for training and match injuries. These outcome measures are reported for anatomical region, body area, tissue type, pathology type, and mechanism of injury. The relative risk (RR) of injury was calculated for potential risk factors (participant demographics [age groups], rugby specific information [level of competition, playing position, highest level of play], medical history of disease [medical risk category], and injury history [acute or chronic injury 12 months prior, severe injury in entire sporting career]) by means of univariate analysis. Results: The primary findings with regards to epidemiology and clinical characteristics are as follows: 1) 60% of players sustained an injury during each season, 2) 64% of all injuries occurred during matches and the overall injury incidence (per 1 000 player hours) was significantly higher in matches (131.1) compared with training (2.4), 3) 84% of injuries were new injuries, 4) during training, most injuries (65%) affected the lower limb, while in matches upper limb (37%) and lower limb injuries (36%) were equally common, 5) training injuries mostly affected the ankle (16%) body area, whereas match injuries more frequently affected the shoulder (20%), 6) the majority of injuries involved muscle/tendon (57%) as the tissue type, of which approximately half were muscle injuries and a third were muscle contusions, 7) the injury severity profile was similar between match and training injuries and more than a quarter of all injuries resulted in time-loss of more than 28 days, 8) contact mechanisms of injury lead to most injuries in matches, whereas non-contact mechanisms accounted for a larger proportion of training injuries, 9) almost half of match injuries occur during the tackle phase (49%), and 10) a high percentage of players could not recall the match period where the injury occurred (24%). The following risk factors associated with incurring an injury during a season were identified: 1) the older age group within the student cohort, 2) higher level of tournament, and 3) any recent injury (past 12 months), 4) a recent injury (past 12 months) to the lower limb. Conclusion: The injured player proportion and match injury incidence were higher in university student rugby players participating in the VC and YG tournaments than has been previously reported in elite professional rugby. The number and severity profiles of training and match injuries were similar. Training injuries mostly occurred in non-contact situations and affected the lower limb, whereas contact injuries were more common in matches and the upper and lower limb were affected at equal frequencies. We show an association between injury risk and age, level of competition, previous acute and/or chronic injury during the past 12 months and specifically a lower limb injury in the past 12 months. The study findings can add to the collective knowledge of injuries and associated risk for injury among student rugby players which in turn may assist medical team members to plan and implement effective injury prevention strategies for this specific population in future.