Étude de la cinématique de la tête, de l’activité électrique cérébrale et des réponses biomécaniques du cerveau lors de la pratique du soccer

Abstract

The diagnosis of traumatic brain injury and especially mild traumatic brain injury (mTBI) is problematic due to the lack of medical tests that allow medical professionals to confirm the injury (McCrory et al., 2017). Currently, sports literature presents different types of analyses used as a mTBI risk indicator to improve the understanding of the risk of head injuries. However, the complexity of mTBI mechanisms makes it difficult to identify a clear agreement upon indicator for the assessment of the risk of head injury. Therefore, the main objective of this research project was to study simultaneously different risk indicators of mTBI, including head kinematics, brain electrical activity and biomechanical responses of the brain tissue in semi professional level female and male soccer players. The head kinematics data were measured using a headband instrumented with the SIM-G (Triax Technologies, Norwalk, Ct). The kinematic data were then compared to the football mTBI criteria established by Pellman et al. (2003), Zhang et al. (2004), Rowson et Duma (2011) et Rowson et al. (2012). The kinematics data were also used to develop the first soccer mTBI risk criterion. Head kinematics helped identify factors which could contribute to cause a risk of mTBI, which are competitive games, heading techniques, physical parameters of soccer balls, temperature, time of play and rotational accelerations. Anthropometric parameters of the head-neck segment also appeared to lead to a greater risk of mTBI in female players than in male soccer players. Brain electrical activity was measured at rest at the end of games using the Muse (Interaxon Inc., Toronto, ON) which has four dry electrodes. These measurements led to notice a relationship between changes in brain electrical activity and the number of head impacts as well as the psychological state of the participants. The relevance of the methodology proposed for on-field brain electrical activity measurements was also confirmed. The biomechanical responses of the brain tissue were calculated using an open-access detailed finite element model of the head. Numerical analysis showed that rotational acceleration is sufficient to study the biomechanical responses of the brain tissue. The analysis of the biomechanical responses of the brain tissue also made it possible to note that the numerical criteria for mTBI in the current literature are not suitable for soccer because of the large variety of definitions between studies. The conclusion of this research seemed to show that the assessment of the risk of head injury while playing soccer cannot be performed using a single mTBI risk indicator. However, the combination of at least two mTBI risk indicators, with the main indicator being head kinematics and either brain electrical activity or biomechanical responses of the brain tissue seemed appropriate for assessing the risk of mTBI in soccer. This research has prompted a reflection on current technologies, highlighting the lack of instruments and tools to measure, analyse and interpreta the data generated by the mTBI risk indicators. New technologies adapted to measurements carried out on the field are therefore essential in the process of understanding mTBI mechanisms, risk indicators and diagnosis.

Date	30 Oct 2020
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Éric Wagnac (Supervisor) & Yvan Petit (Co-supervisor)