Knee medial loading evaluation in walking state via multiple predictors

Objective: Knee medial loading is one of the most important biomechanical variables for knee joint diseases. Some easily-obtained variables, including knee adduction/flexion moment (KAM/KFM) and knee adduction angle (KAA) separately, have been proposed to indicate the variability of the medial loading. The purpose of this study is to undertake an informed evaluation of these predictors in walking task. Methods: In this study, we collected motion and kinetic data for 16 healthy subjects in straight walking. A previously validated musculoskeletal model Freebody 2.1 was used to calculated knee medial force (KMF), KAM, KFM and KAA. Linear regression models were established when KAM, KFM and KAA at peak KAM timing were successively added as predictors. Correlation analysis was used to explore the relationship between predictors. Results: KAA was a significant predictor in walking state, which improved the fit effect of the regression models with the adjusted R2 increasing to 0.809. The correlation analysis revealed that all the three indicators provided unique information for KMF evaluation during walking. Conclusion: Together with KAM and KFM, KAA is a significant predictor for KMF evaluation during straight walk state. Significance: These findings will help improve the accuracy of the evaluation of knee medial loading for clinicians and researchers to predict the risks of knee degeneration.