Finite element analysis on femur subjected to knee joint forces during incline-decline walking

Walking is one of the activities that produce a significant magnitude to joint reaction forces and stresses of human bone. Walking on different ground surfaces contributes to the different loads and stresses, particularly on femur bone. Other than uneven surfaces, walking on certain slope surfaces could also affect the magnitude of joint forces. Therefore, finite element analysis (FEA) was employed in this study to simulate the effect of walking on different slope angles for both incline-decline towards stress and strain responses of the femur bone. A three dimensional (3D) geometrical model of the femur was developed and converted to 3D finite element model. The loading conditions and constraints that reflect to walking on different sloped surfaces were applied on femoral head and patellar surface. Failure risk, stress-strain distribution and maximum stress-strain on femur were obtained from the simulation. The results show that the increase of sloped angles contributes to the increase of von Mises stress and strain as well as maximum principal stress and strain. The study provides an additional insight on the risk of injury due to incline-decline walking for certain angle of slopes.