The valgus collapse position involves knee abduction, hip addiction, and internal rotation, along with limited lower limb triple flexion and trunk bending in the opposite direction during the stabilization phase in a sidecutting task [33; 13; 14; 28; 3]. The valgus collapse generates medial displacement of the ground reaction force vector, which is then centered medial and posterior on the tibial plateau. This results in relative anterior and lateral shear of the tibia with increased ACL load. This position may lead to impingement of the ACL on the lateral femoral condyle [13; 14; 30; 32; 34]. Thus, players who develop this pattern have been shown to be more susceptible to suffering an ACL injury [14; 30; 32]. Meanwhile, Hs play a crucial role as synergists of the ACL [27; 35]. Hs counteract the two main vectors of ACL strain, the anterior component and the lateral component; therefore, they prevent strain damage of the ACL [27; 29; 36]. Females have exhibited lower electromyographical activation (actEMG) ratios of the H during stabilization actions and have shown greater H inhibition due to fatigue compared to males [27; 35]. Furthermore, recent evidence has explained that biceps femoris (BF) and semitendinosus (ST) activationsreveal functional differences controlling knee stability [11; 30; 37]. ST develops three main functions to decrease ACL injury risk. Due to its anatomical positioning, it limits maximal hip internal rotation, thus controlling relative external tibial rotation. The ST also functions as a medial knee stabilizer, compressing the medial knee compartment to counteract excessive knee valgus [11; 38]. Finally, ST has a main role as a \"knee adductor\", avoiding knee abduction that might appear during the valgus collapse in high-intensity tasks [11]. The valgus collapse mechanism is the primary ACL risk factor. Hip abductors and external rotator muscles, such as gluteus maximus (GMax) and gluteus medius (Gm), might be the other keys protecting the ACL, as they act as primary controllers of this mechanism [29; 39]. Nonetheless, little is known about their maximal voluntary isometric contraction torque or about their muscle pattern recruitment or alterations after ACL injury or reconstruction. The study of the GMax and Gm as potential controllers of the knee in the transversal and frontal plane and of the H and Q in the sagittal plane may provide reference neuromuscular data to identify neuromuscular thresholds in relation to the ACL injury risk. These data may increase the effectiveness of ACL prevention programs. In addition, recent studies have introduced an innovation. They consider laterality and its role in the incidence of ACL injury mediated by the valgus collapse mechanism. The study by [PERSON] et al. explains that football players typically develop more injury risk factors in their dominant limb (DL) (defined by the preferred kicking limb) than in their non-dominant limb (NDL) [40]. They argue that two main interdependent factors contribute to this: fatigue and the sports context, which together determine which limb the player uses for stabilization. Consequently, the DL tends to experience fatigue due to its involvement in kicking during matches, without typically serving the stabilization role [14]. Most ACL injury rehabilitation and knee injury prevention programs focus on correcting postural or kinematic alignment to prevent valgus collapse mechanisms. They are based on muscle-strengthening exercises that reproduce general movement patterns. These programs fail to fully explain the ACL injury mechanism and consequently fail to provide a solution to the continuous increase in incidence. Thus, this study aims to (a) evaluate differences in actEMG and force between female football players with previous ACL injury and healthy players in BF, ST, vastus medialis (VM), vastus lateralis (VL), GMax, and Gm during a maximal voluntary isometric contraction and (b) determine if differences occur based on the laterality of the injured limb.