The motion capture and force plates data are essential inputs for musculoskeletal multibody dynamics models to predict in vivo tibiotalar contact forces. However, it could be almost impossible to obtain valid force plates data in old patients undergoing total ankle arthroplasty under some circumstances, such as smaller gait strides and inconsistent walking speeds during gait analysis. To remove the dependence of force plates, this study has established a patient-specific musculoskeletal multibody dynamics model with total ankle arthroplasty by combining a foot-ground contact model based on elastic contact elements. And the established model could predict ground reaction forces, ground reaction moments and tibiotalar contact forces simultaneously. Three patients’ motion capture and force plates data during their normal walking were used to establish the patient-specific musculoskeletal models and evaluate the predicted ground reaction forces and ground reaction moments. Reasonable accuracies were achieved for the predicted and measured ground reaction forces and ground reaction moments. The predicted tibiotalar contact forces for all patients using the foot-ground contact model had good consistency with those using force plates data. These findings suggested that the foot-ground contact model could take the place of the force plates data for predicting the tibiotalar contact forces in other total ankle arthroplasty patients, thus providing a simplified and valid platform for further study of the patient-specific prosthetic designs and clinical problems of total ankle arthroplasty in the absence of force plates data.

运动捕捉和测力板数据是肌肉骨骼多体动力学模型预测体内胫距接触力的重要输入。然而，在某些情况下，例如步态步幅较小和步态分析过程中的步行速度不一致，在接受全踝关节置换术的老年患者中获得有效的测力板数据几乎是不可能的。为了消除测力板的依赖性，本研究通过结合基于弹性接触元件的脚-地面接触模型，建立了具有全踝关节置换术的患者特异性肌肉骨骼多体动力学模型。并且建立的模型可以同时预测地面反作用力、地面反作用力矩和胫距接触力。三名患者在正常行走期间的动作捕捉和测力板数据用于建立患者特定的肌肉骨骼模型并评估预测的地面反作用力和地面反作用力矩。预测和测量的地面反作用力和地面反作用力矩达到了合理的精度。使用脚-地面接触模型预测的所有患者的胫距接触力与使用测力台数据的患者具有良好的一致性。这些发现表明，脚-地面接触模型可以代替测力板数据，用于预测其他全踝关节置换术患者的胫距接触力，