Kinematic analysis of high performance rugby props during scrum training

OBJECTIVE International rugby games have approximately 19 scrums and teams use scrums to establish dominance over the opposition, and to initiate offence. Despite its importance and the issues surrounding scrummaging and injury, there is limited research on the biomechanics of scrimmaging. No scientific research has reported the kinematics of scrummaging in elite rugby players. The purpose of this study was to examine the sagittal plane kinematics of several international rugby props during a combination of both training and game based scrummaging drills in order to develop a greater understanding of the techniques involved. METHODS This study was based on 2-dimensional analyses of (n=5) from an international rugby team during ma-chine (5 and 8-man), and live scrum training. High-speed (500 Hz) and 50 Hz digital video were recorded over 6 trials and analysed using APAS motion analysis software. Paired t-tests were used to test for differences in scrum technique between the scrum drills, and machine and live scrummaging. RESULTS Differences in lower limb kinematics were evident amongst all scrum types. For example, peak hip and knee angular extension velocities were greater for 5-man scrums, while peak horizontal velocities of the CoM were greater for the 8-man scrums. Conversely, peak hip and knee extension velocities for live scrums were slower than during scrum machine training. CONCLUSION It was concluded that clear differences exist in the sagittal plane kinematics of props during different types of scrummaging training. The implications of these findings are considerable, as these data suggest that the exces-sive use of scrummaging machines, plus some scrum training drills (e.g. 5-man) may have a negative training effect. [Oral Presentation presented at: VIth World Congress on Science and Football, Book of Abstracts, January 16-20, 2007, Antalya, Turkey