Measuring rugby concussion injuries

Gregory Tierney 
Trinity College Dublin

Rugby is intrinsically an impact sport, and concussions are a frequent injury within the game. Repeated concussion is an ongoing controversy. My research aims to give us a greater understanding of the dynamics of head impacts in rugby and the mechanism of concussion. Accordingly, my project focuses on using Model Based Image Matching (MBIM) assessment and video evidence to determine the kinematic scenarios and thresholds of concussion injuries in elite rugby union players. 

An expert panel, including Irish Rugby Medical Staff, completed a visual assessment of specific head injury cases to identify high-risk concussion scenarios which were then analysed biomechanically to provide an understanding of the injury kinematics. A skeletal model and virtual environment were manipulated, for each video frame, to fit both the player’s anthropometry and the rugby field. This yielded the player’s kinematics for the head impact.

This process has helped me identify certain risk factors and causes of concussion within the game, which should help with the development of prevention strategies. By reconstructing representative injury cases in this way, we can establish, for the first time, linear and rotational kinematic tolerance thresholds for concussion injuries in rugby.

These kinematic conditions can be used to give us a greater understanding of the mechanism of concussion. Firstly, the kinematic conditions can be inputted into a finite element model of the brain to see exactly what strains are occurring within the brain and where. The results can then be compared to player Head Injury Assessment scores to find a relationship between strain location in the brain and areas of failure within the assessment such as memory, balance and clinical signs. Secondly, the kinematic conditions can be compared to blood biomarker data taken before and after the impact to find a relationship between the kinematics of the impact and levels of certain proteins which pass through the blood-brain barrier due to a head impact. Finally, the kinematic conditions can be inputted into a MADYMO simulation to investigate a range of player positions upon impact and determine which positions yield the lowest kinematic values. All of this information can be used to develop injury prevention strategies when tackling. Identifying ways to train players to tackle in such a way as to minimise or prevent head injuries will help us confront the ongoing controversy of repeated concussion.