Estimation des forces musculaires individuelles des ischio-jambiers lors d’entrainement contre résistance : vers une prédiction des adaptations musculaires

Resistance training induces major muscular adaptations, yet their magnitude and localization vary widely across muscles, even under identical training protocols. This variability may result from neuromechanical differences between muscle heads, including variations in length or muscle force production. The hamstrings provide a relevant model to explore these mechanisms, given their distinct neuromechanical behavior and their frequent targeting in resistance training. This thesis aimed to estimate individual hamstring muscle forces during resistance exercises to better understand the neuromechanical determinants of structural adaptations. A neuromusculoskeletal modeling approach driven by electromyographic data was applied and compared with experimental measures of muscle damage and hypertrophy. The results show that (i) hamstring muscles experience markedly different neuromechanical conditions even within the same exercise, (ii) the interaction between length and force strongly influences the location of training-induced adaptations, and (iii) model-based neuromechanical estimates accurately predict which hamstring head is most affected by training.