  Objective: A numerical 3D model of the human trunk was developed to study the
biomechanical effects of lumbar belts used to treat low back pain. Methods:
This model was taken from trunk radiographies of a person and simplified so as
to make a parametric study by varying morphological parameters of the patient,
characteristic parameters of the lumbar belt and mechanical parameters of body
and finally to determine the parameters influencing the effects of low back
pain when of wearing the lumbar belt. The loading of lumbar belt is modelled by
Laplace's law. These results were compared with clinical study. Results: All
the results of this parametric study showed that the choice of belt is very
important depending on the patient's morphology. Surprisingly, the therapeutic
treatment is not influenced by the mechanical characteristics of the body
structures except the mechanical properties of intervertebral discs.
Discussion: The numerical model can serve as a basis for more in-depth studies
concerning the analysis of efficiency of lumbar belts in low back pain. In
order to study the impact of the belt's architecture, the pressure applied to
the trunk modelled by Laplace's law could be improved. This model could also be
used as the basis for a study of the impact of the belt over a period of
wearing time. Indeed, the clinical study shows that movement has an important
impact on the distribution of pressure applied by the belt.
