Abstract
Rugby tackles can cause head acceleration events (HAEs) which may acutely and chronically affect brain health. This study aimed to investigate the varying proportions, impact forces and rugby-specific factors of tackles from different directions relative to the ball carrier which may illuminate strategies to reduce injury and health risks. Boys from four youth boys' teams in New Zealand (one U13 club: n = 19 players, 13 matches; two U16 club: n = 41, mean of 31.5 matches; one U16 representative: n = 26, 8 matches) wore instrumented mouthguards and all matches were videoed and analyzed to verify the collisions resulting in a tackle and code them based on rugby-specific and biomechanical factors (anticipation, falling, head position, face position). Of the 2539 tackles resulting in HAEs, most were front-on (56-64%). Tackle direction had no significant effect on either mean peak linear or rotational acceleration, however significantly fewer tackles from the rear resulted in impacts that would trigger an elite rugby head injury assessment than tackles from the front and side. The older and more skilled players more often had correct head positioning in front and side-on tackles, whereas almost none of the tackles from the rear had incorrect head positioning. Additional training focus should be given to tackles from the side and rear with younger players as they have poorer anticipation in these directions often resulting in higher HAE magnitude. Face up tackling seems to be best for reducing impact forces in tackles from behind, while face down tackling appears to be safest for front-on tackles.