Background There is a perceived high risk of injury within youth rugby, but the available evidence in this population is limited. Understanding injury rates and patterns can inform injury reduction strategies.

Objective To describe the incidence and severity of schoolboy rugby injuries and determine whether there are differences between age groups.

Design A two-season (2017–19) prospective cohort study.

Setting English secondary schools.

Participants Schoolboy teams in the under-13 (U13), under-15 (U15) and under-18 (U18) age groups.

Assessment of Risk Factors Match exposure and the severity (days lost), type and event associated with 24-hour time-loss injuries.

Main Outcome Measures Injury incidence (injuries/1000h) and burden (days lost/1000h).

Results 11,706 player-hours and 379 match injuries from 66 teams were collected. The U18 age group had a significantly higher injury incidence (37.2 injuries/1000h, 95% CI: 33.1 to 41.8) than the U15’s (24.7, 95% CI: 19.8 to 30.8) and U13’s (20.8, 95% CI: 13.6 to 31.9) (P<0.01), which were not significantly different (P=0.24). The mean severity was 29 days lost (95% CI: 26 to 33) for U18, 31 (95% CI: 25 to 39) for U15 and 20 (95% CI: 13 to 31) for U13. Injury burden differed significantly between all groups (U18, 1085 days/1000h, 95% CI: 965 to 1220; U15, 767, 95% CI: 615 to 956; U13, 423, 95% CI: 276 to 648; P<0.01). Contact events accounted for 86% of all injuries, with the tackle accounting for 56%. This was the most common event associated with injury at U18 (22.2 injuries/1000h), U15 (11.4/1000h) and U13 (10.4/1000h). The most common injury type was concussion at U18 (9.0 injuries/1000h) and U15 (5.1/1000h) and bruising/haematoma (5.2/1000h) at U13.

Conclusions The U18 age group had the highest injury incidence and burden. The tackle was the most common injury event and should be the focus of further investigation or intervention.