A review of the biomechanical determinants of rugby scrummaging performance.

Background: The scrum is a physical contest unique to the game of rugby union, important for determining match outcomes.

Objective: This review will describe the current understanding of the kinetic and kinematic determinants of successful scrum performance to support coaching interventions and inform on future research.

Methods: Literature review.

Results: Individual and combined scrumming forces increase with playing level but there is no concurrent increase in body mass or player strength. There is very little variation in individual kinematics between individuals and across levels of play, suggesting that there are limited possible techniques for successful scrummaging. Live scrum contests are dynamic and require constant adjustments to body positions in response to increased compressive force and exaggerated lateral and vertical force components. Skilled performers are able to exert high levels of horizontal force while maintaining effective body positions within this dynamic environment.

Conclusion: Success in scrummaging depends on the optimisation of joint angles and force production at the individual level, and the coordination of effort at a team level. The analysis presented here demonstrates that producing large scrum-specific forces and achieving the optimal 'body shape' are essential for successful scrum performance.