Photoelastic analisys in the lower region of vertebral body L4.
OBJECTIVE
To analyze the shear forces on the vertebral body L4 when submitted to a compression force by means of transmission photoelasticity.


METHODS
Twelve photoelastic models were divided into three groups, with four models per group, according to the positioning of the sagittal section vertebrae L4-L5 (sections A, B and C). The simulation was performed using a 15N compression force, and the fringe orders were evaluated in the vertebral body L4 by the Tardy compensation method.


RESULTS
Photoelastic analysis showed, in general, a homogeneous distribution in the vertebral bodies. The shear forces were higher in section C than B, and higher in B than A.


CONCLUSIONS
The posterior area of L4, mainly in section C, showed higher shear concentrations, corresponding to a more susceptible area for bone fracture and spondylolisthesis. Economic and Decision Analyses - Development of an Economic or Decision Model. Level I.
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of the Faculdade de Medicina de RibeirãoPreto da Universidade de São Paulo - RibeirãoPreto, SP, Brazil.
Sarah Fakher
SF
Fakhouri
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of the Faculdade de Medicina de RibeirãoPreto da Universidade de São Paulo - RibeirãoPreto, SP, Brazil.
Ariane
A
Zamarioli
Department of Mechanical Engineering of Universidade Federal doTriânguloMineiro MG, Brazil.
Marcos Massao
MM
Shimano
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of the Faculdade de Medicina de RibeirãoPreto da Universidade de São Paulo - RibeirãoPreto, SP, Brazil.
Helton Luiz Aparecido
HL
Defino
Laboratório de Projetos Mecânicos Professor Henner Alberto Gomide of the Mechanical Engineering School of Universidade Federal de Uberlândia, MG, Brazil.
Cleudmar Amaral
CA
Araujo
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of the Faculdade de Medicina de RibeirãoPreto da Universidade de São Paulo - RibeirãoPreto, SP, Brazil.
Antonio Carlos
AC
Shimano
Biomechanics; Spine; Tension