Neuromuscular control, squat depth, and dynamic knee valgus: anatomical and biomechanical interactions in lower limb function

Lower limb function during dynamic tasks such as squatting and jumping is influenced by a web of anatomical and neuromuscular factors. Among these, dynamic knee valgus has drawn considerable attention because of its frequent association with anterior cruciate ligament injury, patellofemoral pain, and movement inefficiency. Yet, how squat depth, neuromuscular control, and underlying anatomy interact to shape valgus mechanics is still not entirely clear. This review brings together evidence from biomechanics, anatomy, and applied physiology to examine these relationships. Deep squats, for instance, appear to recruit a broader spectrum of lower limb musculature and enhance strength gains, but they also increase joint loading and may exacerbate frontal-plane deviations in vulnerable individuals. Neuromuscular control — particularly the activation of hip abductors and external rotators — seems central to maintaining knee alignment, though findings are not always consistent across age, sex, or training level. Studies on Q-angle, hip structure, and ankle mobility add another layer, suggesting that some anatomical predispositions may set the stage for valgus collapse, even before neuromuscular strategies come into play. Training interventions, ranging from plyometrics to resistance band cueing, generally improve alignment, but their long-term effectiveness is less certain. Measurement, too, is a sticking point; reliance on 2D video may underestimate true valgus angles compared with 3D motion analysis. Altogether, the literature paints a nuanced picture: squat depth, anatomy, and neuromuscular control are intertwined, but not in simple cause-and-effect terms. Understanding this interplay may help refine injury prevention programs and guide safer movement practices in sport and rehabilitation.