Treatment design for musculoskeletal disorders using in silico patient-specific dynamic simulations is becoming a clinical possibility. However, these simulations are sensitive to model parameter values that are difficult to measure experimentally, and the influence of uncertainties in these parameter values on the accuracy of estimated knee contact forces remains unknown. This study evaluates which musculoskeletal model parameters have the greatest influence on estimating accurate knee contact forces during walking. We performed the evaluation using a two-level optimization algorithm where musculoskeletal model parameter values were adjusted in the outer level and muscle activations were estimated in the inner level. We tested the algorithm with different sets of design variables (combinations of optimal muscle fiber lengths, tendon slack lengths, and muscle moment arm offsets) resulting in nine different optimization problems. The most accurate lateral knee contact force predictions were obtained when tendon slack lengths and moment arm offsets were adjusted simultaneously, and the most accurate medial knee contact force estimations were obtained when all three types of parameters were adjusted together. Inclusion of moment arm offsets as design variables was more important than including either tendon slack lengths or optimal muscle fiber lengths alone to obtain accurate medial and lateral knee contact force predictions. These results provide guidance on which musculoskeletal model parameter values should be calibrated when seeking to predict in vivo knee contact forces accurately.

使用in silico 的肌肉骨骼疾病治疗设计特定于患者的动态模拟正在成为一种临床可能性。然而，这些模拟对难以通过实验测量的模型参数值很敏感，并且这些参数值的不确定性对估计的膝接触力的准确性的影响仍然未知。本研究评估了哪些肌肉骨骼模型参数对估计步行过程中准确的膝关节接触力影响最大。我们使用两级优化算法进行评估，其中肌肉骨骼模型参数值在外层调整，肌肉激活在内层估计。我们使用不同的设计变量集（最佳肌纤维长度、肌腱松弛长度、和肌肉力臂偏移）导致九个不同的优化问题。当同时调整肌腱松弛长度和力臂偏移量时，可以获得最准确的外侧膝关节接触力预测，同时调整所有三种类型的参数时，可以获得最准确的内侧膝关节接触力估计。将力臂偏移作为设计变量比单独包括肌腱松弛长度或最佳肌纤维长度更重要，以获得准确的膝关节内侧和外侧接触力预测。这些结果为在寻求准确预测体内膝关节接触力时应校准哪些肌肉骨骼模型参数值提供了指导。当同时调整肌腱松弛长度和力臂偏移量时，可以获得最准确的外侧膝关节接触力预测，同时调整所有三种类型的参数时，可以获得最准确的内侧膝关节接触力估计。将力臂偏移作为设计变量比单独包括肌腱松弛长度或最佳肌纤维长度更重要，以获得准确的膝关节内侧和外侧接触力预测。这些结果为在寻求准确预测体内膝关节接触力时应校准哪些肌肉骨骼模型参数值提供了指导。当同时调整肌腱松弛长度和力臂偏移量时，可以获得最准确的外侧膝关节接触力预测，同时调整所有三种类型的参数时，可以获得最准确的内侧膝关节接触力估计。将力臂偏移作为设计变量比单独包括肌腱松弛长度或最佳肌纤维长度更重要，以获得准确的膝关节内侧和外侧接触力预测。这些结果为在寻求准确预测体内膝关节接触力时应校准哪些肌肉骨骼模型参数值提供了指导。当所有三种类型的参数一起调整时，可以获得最准确的膝关节内侧接触力估计。将力臂偏移作为设计变量比单独包括肌腱松弛长度或最佳肌纤维长度更重要，以获得准确的膝关节内侧和外侧接触力预测。这些结果为在寻求准确预测体内膝关节接触力时应校准哪些肌肉骨骼模型参数值提供了指导。当所有三种类型的参数一起调整时，可以获得最准确的膝关节内侧接触力估计。将力臂偏移作为设计变量比单独包括肌腱松弛长度或最佳肌纤维长度更重要，以获得准确的膝关节内侧和外侧接触力预测。这些结果为在寻求准确预测体内膝关节接触力时应校准哪些肌肉骨骼模型参数值提供了指导。