Head Acceleration Event Probabilities During Standardised Contact Drills in Academy Men's Rugby League

This study investigated head acceleration event (HAE) probabilities between common contact‐drills in rugby league. Fifteen professional male academy players participated in three training sessions, completing standardised contact‐drills while wearing custom‐fitted iMGs, all sessions were filmed. HAE data (peak linear acceleration and peak angular acceleration) were captured, synchronised, and processed alongside video data. Binomial logistic regression and ordinal mixed‐effect regression models were used to calculate overall and exceedance probabilities. Data included 1402 (93 ± 50 per player) contact‐drill observations, of which 133 had HAEs ≥ 5 g (9 ± 8 per player). Substantial variability in probability for HAEs ≥ 5 g (1.3%–41.3%) was observed across drills. Standing wrestle had the highest HAE ≥ 5 g probability (41.3%; CI: 31.0%–52.3%), while tackle shield hits at 1 m had the lowest (1.3%; CI: 0.5%–3.4%). HAE probability was greater for tacklers than ball‐carriers. Overall, probability of a HAE ≥ 25 g was < 1.1%. Standardised contact‐drills varied in HAE probabilities, but chances of higher magnitude HAEs was low for all drills. Overall, the probability of a HAE during standardised contact‐drills was low, although practitioners should consider the differences (i.e., the variability) in HAE probabilities when managing HAE training exposure.