A Valid Model for Prediction Tibiofemoral Force for Healthy People Based on Static Optimization

Ali Mamdouh Mohamed,Ronglei Sun

doi:10.1109/access.2021.3085859

Ali Mamdouh Mohamed, Ronglei Sun

Open Access

https://doi.org/10.1109/access.2021.3085859

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Abstract

The musculoskeletal model plays an important role in the investigation of human lower limb diseases. Although different methods are used for musculoskeletal models, the prediction of the tibiofemoral and muscle forces still needs more improvements. This paper introduces a model for the lower limb; 3-DOF hip, 1-DOF knee, and 3-DOF ankle. The model estimates the tibiofemoral and muscle forces based on static optimization. The shank and the foot are considered as one element to avoid the high-cost computation of the traditional inverse dynamic method. The direction of the tibiofemoral force is estimated based on the analytical method to tune the weight factors of the predicted force. Two subjects (A and B) performed walking at 1m/s for about 5 gait cycles with recording the kinematics, ground reaction force (GRF), and foot center of pressure (CoP) and electromyographic (EMG) signals. A static optimization technique was performed to predict the tibiofemoral and 6 lower limb muscles forces based on the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> -Newton law in three-dimensional (3D). Muscles moment arms were verified by compared to measured data in the literature. The validity of the model was guaranteed by testing the model on a subject of total knee replacement (TKR) and compared the predicted tibiofemoral force with the measured one. The predicted tibiofemoral forces had the root mean square error (RMSE) of 0.19, 0.56, and 0.43 BW for TKR subject, subject A and subject B, respectively. The predicted muscles force was validated by comparing it to EMG signals. The analysis and the validation of the model showed that it could be used for different activities like walking and running and assessment rehabilitation devices such as knee brace.

Highlights

The knee plays an important role in the balance of the whole body
The method used here was to reduce the complexity of the system equations by decreasing the number of unknown forces [27], [28] unlike the traditional inverse dynamic method. while other models transfer the force from one joint to the the shank and the foot were represented as one element and the moment of inertia was calculated for each segment w.r.t femur origin using the parallel axes theorem
The predicted tibiofemoral forces were compared to other models in the literature, for the 1st and 2nd peak values of the medial and lateral tibiofemoral

Summary

Introduction

The knee plays an important role in the balance of the whole body. The knee shows different characteristics such as various load support, according to the activities [1], and different kinematics according to gender [2], and healthy conditions (i.e. healthy vs. osteoarthritis)[3]. The knee shows different characteristics such as various load support, according to the activities [1], and different kinematics according to gender [2], and healthy conditions (i.e. healthy vs osteoarthritis)[3]. The knee diseases such as osteoarthritis and anterior circulate ligament (ACL) deficiency encourage scientist to develop a musculoskeletal model to describe the cause and prognosis of these diseases; like cartilage deformation[4], [5]. Different knee features overcome deciding the suitable treatment for diseases

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