In-silico pre-clinical trials are made possible by a new simple and comprehensive lumbar belt mechanical model based on the Law of Laplace including support deformation and adhesion effects

PLoS One. 2019 Mar 6;14(3):e0212681. doi: 10.1371/journal.pone.0212681. eCollection 2019.


Lower back pain is a major public health problem. Despite claims that lumbar belts change spinal posture due to applied pressure on the trunk, no mechanical model has yet been published to prove this treatment. This paper describes a first model for belt design, based on the one hand on the mechanical properties of the fabrics and the belt geometry, and on the other hand on the trunk geometrical and mechanical description. The model provides the estimation of the pressure applied to the trunk, and a unique indicator of the belt mechanical efficiency is proposed: pressure is integrated into a bending moment characterizing the belt delordosing action on the spine. A first in-silico clinical study of belt efficiency for 15 patients with 2 different belts was conducted. Results are very dependent on the body shape: in the case of high BMI patients, the belt effect is significantly decreased, and can be even inverted, increasing the lordosis. The belt stiffness proportionally increases the pressure applied to the trunk, but the influence of the design itself on the bending moment is clearly outlined. Moreover, the belt/trunk interaction, modeled as sticking contact and the specific way patients lock their belts, dramatically modifies the belt action. Finally, even if further developments and tests are still necessary, the model presented in this paper seems suitable for in-silico pre-clinical trials on real body shapes at a design stage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Humans
  • Lordosis* / pathology
  • Lordosis* / physiopathology
  • Low Back Pain* / pathology
  • Low Back Pain* / physiopathology
  • Lumbar Vertebrae* / pathology
  • Lumbar Vertebrae* / physiopathology
  • Lumbosacral Region / pathology
  • Lumbosacral Region / physiopathology
  • Male
  • Middle Aged
  • Models, Biological*

Grants and funding

This work has been partially funded by Thuasne under ANRT PhD grant process. Reynald Convert and Rebecca Bonnaire, both employed by Thuasne, contributed to this work at every level of the research process – see Author contribution for details. Thuasne is a lumbar belt manufacturer. There was no additional external funding received for this study. Other resources for this work are state-funded via the University or the University Hospital budget. Thuasne provided support in the form of salaries for authors RB and RC, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.