Mechanisms of knee injuries in male university rugby union players: a systematic video analysis and injury surveillance study

Abstract

Knee injuries in rugby union have higher incidence and severity than other injury types. However, the underlying mechanisms and trauma remain unclear. This study aimed to identify knee injury trends and clarify the associated mechanisms in male university rugby players using longitudinal injury surveillance and video analysis. An observational study with longitudinal injury surveillance included 198 university male rugby players who played at least one season over a six-season period (2017–2022). The mean incidence, severity, and burden of injuries were calculated by position and injury type. Video data of knee injuries in matches were analyzed by three analysts, who independently assessed variables, including mechanism/play, movement/posture, and external factors. Injury mechanisms were classified as direct, indirect, and non-contact. The incidence of knee injuries was 8.3/1000 h, with 29 videos analyzed. Indirect contact injury was the most frequent, with an incidence of 3.7/1000 h and a burden of 380 days/1000 h. A significant association was found between injury severity and movement direction, with being tackled from downwards and sideways directions showing a significant difference compared to other directions (Cramer’s V = 0.44). Most knee injuries were caused by being tackled, a heel strike, and an upright body position. Indirect injuries, the most frequent knee injury mechanism, imposed the highest burden. Movement direction may further affect injury severity. Despite their lower incidences, these injuries cause greater burden and severity than those observed in professional rugby, emphasizing the need for specialized prevention programs.