Peak Compression Force Physics in Rugby Union Scrum

Abstract

Scrums play a major role in Rugby Union games, and are historically known as a showdown between the two packs of opposing teams, composed of their eight forwards players organized in a 3-4-1 configuration, respectively. We investigate scrum mechanics by working with professional male forward players from Racing 92, a high-level French Rugby club, and measuring the forces they apply on the French Rugby Federation instrumented scrum machine. Signal analysis reveals two major phases in the force production during a scrummaging effort: an impulsive engagement force, and then a force sustained for a few seconds. We experimentally compare individual performances of the engagement phase. We discuss the influence of the mass and the engagement speed of the players, and we introduce the model we are investigating to describe the individual impact on a scrum machine. We expect this model to be the elementary component of a collective model of a pack.

Keywords

• rugby union scrum
• peak compression force
• mass-spring-damper model