Centre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Southport, QLD, Australia.
J Biomech. 2013 Nov 15;46(16):2778-86. doi: 10.1016/j.jbiomech.2013.09.005. Epub 2013 Sep 12.
Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model.
估算胫股关节接触力对于理解膝关节骨关节炎的发生和发展非常重要。然而，胫股接触力的预测受到许多因素的影响，包括肌肉力和膝关节的解剖表示。本研究旨在通过校准的基于肌电的膝关节神经肌肉骨骼模型研究个体特定的几何形状和膝关节运动学对胫股接触力预测的影响。一名佩戴有仪器化全膝关节置换的参与者以自选择的速度行走，同时测量内侧和外侧胫股接触力、地面反作用力、全身运动学和下肢肌肉活动。通用和个体特定的膝关节几何形状和运动学的组合导致使用了四个不同的 OpenSim 模型来估计肌肉-肌腱长度和力臂。个体特定的几何模型是从 CT 扫描创建的，代表胫骨相对于股骨的平移的个体特定的膝关节运动学是从透视获得的。使用一个行走试验对肌电驱动的模型进行校准，但使用三个不同的成本函数来跟踪膝关节屈伸力矩，同时在估计的关节接触力上施加和不施加约束。然后，校准后的模型预测了另外五个不同行走试验的内侧和外侧胫股接触力。与使用通用肌肉骨骼模型相比，使用个体特定模型并最小化峰值胫股接触力分别将内侧接触力的准确性提高了 47%，将外侧接触力的准确性提高了 7%。
