Abstract:

BACKGROUND: As the the pelvis has complex structure, the studies of pelvis biomechanical properties are fewer in sitting stance. Finite element analysis is accepted gradually for biomechanics of the pelvis.
OBJECTIVE: To study the stress distribution on the pelvis of the adult in static sitting stance with three-dimensional finite element model.
METHODS: One healthy volunteer was scanned by multi-slices computerized tomography (MSCT). The three-dimensional images of the pelvis were reconstructed with the software Mimics 10.0. With the use of Geomagic and Proe5.0, the three-dimensional model of the pelvis was imported into the ANSYS10.0. Digital three-dimensional structures of the pelvic, such as ligament, were added to the three-dimensional model with powerful pre-processing modular of ANSYS. Finally, the integrated three-dimensional finite elemental model of the pelvis was established. The vertical load pressure (600 N) was exerted on the upper terminal plate of the first body of the sacrum to simulate sitting biomechanics. The stress, strain and displacement nephogram were obtained under axial load.
RESULTS AND CONCLUSION: The distribution of stress in bilateral iliac bones was equal. The stress passed through the ala of sacrum and the sacroiliac joint to the tuberodties of ischium. The highest stress was found at the tuberodties of ischium. The von Mises stress and strains for specific location could reflect the characteristic biomechanics of the pelvic ring, implying the accuracy of the finite element model. The results agreed with those by other biomechanics test. The established three-dimensional finite element model of normal adult is valid and reasonable. It can be used for biomechanical analysis and also can meet the needs of clinical situation.