Pressure Distribution During Various Movement In 3D Modeling of Human Knee Joint with non-Newtonian Fluid

This paper introduced a new three dimensional model of human’s knee joint which is used a non- Newtonian synovial fluid to solve the transient Couchy equations during two prevalent types of knee movement; climbing stairs and gating. This simulation allowed computing the pressure variation in different 3D points and determining the most critical plate in each percent of cycle that bears the maximum pressure and is more prone to arthritis. This approach gives the advantages to specify the role of important parameters such as body weight, synovial density and the rotational velocity in increasing the pressure of synovial fluid. The results show in the present of the body weight the maximum pressure through climbing stairs is approximately 9X higher than walking while by neglecting the body weight the walking motion is 4.5X more destructive because of three times higher viscous fluid. Obesity not only increases the static pressure on the synovial fluid but also it causes higher dynamic pressure as the results elucidate gaining weight about 30 kg causes 4 times higher pressure. The graphs also demonstrates by decreasing synovial density from 1450 to 1000 and hyaluronic concentration 0.4 to 0.1 , the maximum exerting pressure to the knee joint drops %20 and %75 respectively On the other hand, the maximum shear stress on the ball surface in walking motion is %17 higher than gating because of rotating faster. Furthermore, the pick of pressure gradient and relative viscosity occurred when the spinning direction reversed while the climax of shear stress on the ball surface just depends on the extremum points of rotational velocity function.

کلیدواژه ها:

Knee joint ، Synovial fluid ، Acid hyaluronic ، articulation