Training load and injury surveillance in Leinster SChoolboy RUgby players: the SCRUm cohort study

To describe training loads and injury incidences, and explore their relationship in senior schoolboy rugby players in Leinster, Ireland.

Prospective cohort study conducted during the 2019-2020 season. Methods aligned with consensus statements for rugby injury surveillance research. Injuries were coded using the Orchard Sports Injury Classification System (OSICS) version 10.1 and recorded using the World Rugby Injury Surveillance System. Training load measures (session type, duration and rate of perceived exertion) were recorded by the players using The Sports Office smartphone application.

In total, 463 participants (mean age 17, (SD=0.9 years)) in 16 schools provided data over 20 weeks. Injury incidence per 1000 player hours was 19.9 (95% CI: 15.2 to 25.6) match injuries and 0.7 (95% CI: 0.4 to 1.0) training injuries. Median injury severity was 22 days (95% CI: 17 to 28) lost for match injuries and 14 days (95% CI: 5 to 41) lost for training injuries. Frequent injury sites included shoulder (n=23, 27%), head (n=22, 26%), wrist/hand (n=9, 11%), ankle (n=8, 10%) and knee (n=5, 6%). Tackle accounted for 49% of injuries. Players' recording of individual training load showed 11.5% compliance. Exposure was calculated as 31 141 training hours and 3063 match hours. Training sessions included conditioning weights (31%), rugby skills: non-contact (28%) and semicontact (24%), with variation in proportion of sessions across schools.

Match activity and tackle events accounted for most injuries. Training exposure and type varied widely across schools. Low compliance in recorded individual training load limited analysis of association with injury risk, highlighting the challenge in identifying injury risk factors in an adolescent cohort.