Determination of stresses on the HIP joint during different daily activities

number: 
2858
English
Degree: 
Author: 
Mustafa Yousif Aziz
Supervisor: 
Dr. Albert E. Yousif
year: 
2012
Abstract:

Biomechanics is a field that combines the disciplines of biology and engineering mechanics and utilizes the tools of physics, mathematics, and engineering to quantitatively describe the properties of biological materials. Finite element modeling has been widely used to describe the mechanical behavior of the long bones which have been created from CT (Computer Tomography) images. In this study a three dimensional model of the human femur bone has been developed, the model used represents healthy adult individual of 40 year old, the model was analyzed using ANSYS Workbench (12.1).The behavior of the bone has been assumed as orthotropic , homogeneous and empirical relationships that correlate the Young’s modulus with the density have been used to assign the material properties for the femur model. The data associated with the hip contact forces for (normal walking, going downstairs, going upstairs, standing up, sitting down and knee bending) during one cycle has been employed on the femur bone in order to investigate the behavior of the femur bone during these daily activities. The finite element results for normal stresses were (normal walking= 9.48 MPa, going downstairs =11.47 MPa , going upstairs =10.25 MPa , standing up = 6.85 MPa, sitting down = 5.55 MPa and knee bending = 5.14 MPa), all of those values are located at the neck of femur and Equivalent von –Mises stresses were (normal walking = 34.50 MPa at the medial surface of the body of femur located 5 cm distal to the lesser trochanter, going downstairs = 46.22 MPa at the medial surface of the body of femur located 5 cm distal to the lesser trochanter, going upstairs = 66.37 MPa at the medial surface of the body of femur located proximal to the distal condyles of the femur, standing up = 23.15 MPa at the medial surface of the body of femur located 5 cm distal to the lesser trochanter, sitting down = 15.72 MPa at region located below the lesser trochanter and knee bending = 14.14 MPa at region located below the lesser trochanter) and they were compared with previous studies. The behavior of the stresses that obtained in the present study is similar to those found in the literature. The results of the analysis are helpful for the orthopedic surgeons to understand the biomechanical behavior of the femur bone and also important for surgeons in femur surgeries and bone prosthesis.