Virtual reality assessment of rugby lineout throw kinematics

Abstract

The lineout throw in the sport of Rugby Union is a crucial component in determining whether a team wins possession of the ball. The accuracy and timing of the throw are both important factors in determining whether the opposition can intercept the ball, and these components are determined by the thrower's technique and ability to identify the target. A virtual reality environment, NuView stereo-imaging device and a digital high-definition video camera were used to capture stereoscopic video footage of players during outdoor training. The video footage was presented to eight elite rugby players in life-size stereoscopic 3D as they attempted to perform a lineout as if in a real game. A custom-built laser device measured the accuracy of the virtual throws. In addition, a 12 camera motion analysis system tracked body movements, to help determine lineout throw variables associated with accurate throwing. In the trial of the virtual reality system, statistical and practically significant differences were found between accurate and inaccurate throws for the lineout throw variables; elbow separation (accurate 5.2% greater than inaccurate), front foot step (94.5 mm longer), trunk flexion (5°greater), and follow though (17°higher). These four lineout throw variables are recommended to coaches and players as important features to concentrate on when trying to enhance lineout throw accuracy.

Keywords:

• virtual reality
• rugby kinematics
• stereoscopic video
• projectile tracking

Acknowledgements

The authors would like to thank the following people for their contributions to this research: Professor Roger Bartlett, University of Otago; Professor Peter Milburn, Griffith University; Mr Gavin Kennedy, University of Otago, and Mr Peter Brook, Otago Polytechnic. Thanks are also due to the New Zealand Rugby Union and Otago Polytechnic for funding components of this project.