Torsional profiles of the lower limbs, such as femoral anteversion, can dictate gait and mobility, joint biomechanics and pain, and functional impairment. It currently remains unclear how the interactions between femoral anteversion, kinematics, and muscle activity patterns contribute to joint biomechanics and thus conditions such as knee pain. This study presents a computational modeling approach to investigating the interactions between femoral anteversion, muscle forces, and knee joint loads. We employed an optimal control approach to produce actuator and muscle-driven simulations of the stance phase of gait for femoral anteversion angles ranging from −8° (retroversion) to 52° (anteversion) with a typically developing baseline of 12° of anteversion and implemented a Monte Carlo analysis for variations in lower limb muscle forces. While total patellofemoral joint load decreased with increasing femoral anteversion, patellofemoral joint load alignment worsened, and knee abduction/adduction magnitude increased with both positive and negative changes in femoral anteversion (p < 0.001). The rectus femoris muscle was found to greatly influence patellofemoral joint loads across all femoral anteversion alignments (R > 0.8, p < 0.001), and the medial gastrocnemius was found to greatly influence knee abduction/adduction moments for the extreme version cases (R > 0.74, p < 0.001). Along with the vastus lateralis, which decreased with increasing femoral anteversion (R = 0.89, p < 0.001), these muscles are prime candidates for future experimental and clinical efforts to address joint pain in individuals with extreme femoral version. These findings, along with future modeling efforts, could help clinicians better design treatment strategies for knee joint pain in populations with extreme femoral anteversion or retroversion.

中文翻译：

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髌股关节负荷和膝关节外展/内收力矩对股骨倾斜度和个体肌肉力量的变化很敏感

下肢的扭转曲线，例如股骨前倾角，可以决定步态和活动能力、关节生物力学和疼痛以及功能障碍。目前尚不清楚股骨前倾角、运动学和肌肉活动模式之间的相互作用如何导致关节生物力学以及膝痛等疾病。本研究提出了一种计算建模方法来研究股骨前倾角、肌肉力量和膝关节负荷之间的相互作用。我们采用最佳控制方法来模拟步态的执行器和肌肉驱动模拟，股骨前倾角度范围从 −8°（后倾）到 52°（前倾），通常发展基线为前倾 12°，并实施下肢肌肉力量变化的蒙特卡洛分析。p  < 0.001）。发现股直肌对所有股骨前倾排列的髌股关节负荷有很大影响（R  > 0.8，p  < 0.001），并且发现内侧腓肠肌对极端版本情况下的膝关节外展/内收力矩有很大影响（R  > 0.74） , p  < 0.001)。与股外侧肌一起，随着股骨前倾角的增加而减少（R  = 0.89，p < 0.001)，这些肌肉是未来实验和临床努力的主要候选者，以解决极端股骨前倾个体的关节痛。这些发现以及未来的建模工作可以帮助临床医生更好地设计针对股骨极端前倾或后倾人群膝关节疼痛的治疗策略。