Identification de caractéristiques physiques et neurocognitives affectant la biomécanique de l'atterrissage d'un athlète

Abstract

The anterior cruciate ligament (ACL), is one of the most injured structures in sporting field. In average, 70% of the injury occurred during a non-contact mechanism which results in improper movements of the body as in poorly controlled landing. Neuromuscular training has been implemented in injury prevention programs in order to delay the negative effects of muscle fatigue on landing strategy. Nevertheless, ACL injuries still affect athletic population. Recent studies have shown a link between landing biomechanics and neurocognitive performance. However, the cognitive load used rarely reflects the one observed in a real game situation and these studies did not try to correlate the effects of this link with other simple cognitive or motor tests. The purpose of this project was to investigate the combined effect of perceptivo-cognitive loading and physical fatigue on landing biomechanics in a real game situation, and to identify the correlation between this effect and simple tasks which can be used to detect the athletes likely to get injured. The cognitive performance of sixteen healthy athletes was recorded with the IVA-AE2 software. Then the impact of a multiple objects tracking (MOT), on a simple motor task has been evaluated. The biomechanical data of bilateral landings has been recorded in two conditions: without and with simultaneous performance of the MOT. The landings exercises in the both conditions have been performed again after the completion of a fatigue protocol. The flexion angles at the trunk and the flexion, abduction and internal rotation angles at the hip and knee have been measured at initial contact and peak stance phase. Fatigue induces a decrease in flexion angles at the hip and knee joint at initial contact. The MOT has no effect on landing biomechanics. However, fourteen subjects displayed modifications of flexion angles at the trunk, hip and/or knee when practicing the landing task in combination with the MOT. There are no differences between subjects affected by MOT and subjects who did not in regards to cognitive performance and the effect of the MOT on a simple motor task. The MOT had impact the execution of a simple motor task by decreasing the motor performance of the athletes. The modifications of the landing strategy associated with the performance of the cognitive task are known to increase the stress applied on the ACL. Embed neurocognitif training in injury prevention programs may decreased the effect of a cognitive load in a real game environment. Complementary studies are necessary to evaluate the efficiency of this training on the decrease of injury rate.

Date	21 Dec 2018
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	David Labbé (Supervisor) & Jocelyn Faubert (Co-supervisor)