Assessment of the mechanical and trophic properties of thigh muscles in two clinical situations of disuse : ankle and knee sprain ; Evaluation des propriétés mécaniques et trophiques des muscles de la cuisse dans deux situations cliniques de sous-utilisation : l'entorse de cheville et l'entorse de genou

The goal of this work is to bind the trophic, mechanical and neurological aspects of the neuromuscular response to better understand and anticipate its adaptation to current clinical settings. We have constructed 2 clinical studies. The first study, entitled "The hamstrings are more impacted than the quadriceps after severe ankle sprain", studies the trophic and mechanical adaptation of the thigh muscles following a severe ankle sprain. We showed that the quadriceps (Q) and hamstring (H) muscles showed a significant loss of strength after 2 weeks of unloading. The H are more impacted than the Q. On our perimetry assessments, we did not find evidence of amyotrophy in the thigh. We hypothesize that neurological phenomena explain this significant and rapid decrease in strength. We have shown the interest of coupling the results of peak concentric dynamic torque and total work on isokinetic fatigue tests at 180°/s to evaluate dynamic strength. The second study focuses on the assessment of trophicity, strength and neural control of thigh muscles after anterior cruciate ligament (ACL) surgery. We added MRI segmentation assessments of the muscles of interest (Q and H) and surface electromyography (SEMG) recording coupled with dynamometric testing (ISO), compared to the previous study. Resumption of sports activities at the same level as before the injury is the main goal of the patients, but most of them do not regain this level. There is no consensus on the time frame for return to sport.The goal of this study is to determine whether certain muscular properties can condition the quality of the recovery of the movement as much on the aspect of stabilization of the knee as on the production of force and muscular fatigability. The study of the control group did not reveal any significant difference between the two limbs of the subjects for all the variables of interest. In the operated group, a comparison of the data from the uninjured limbs to the control group showed no significant difference for MRI, ISO, and SEMG ...