Investigation of postero-anterior mobilization in the lumbar spine: A finite element analysis study

Abstract

Background/Aim: Postero-anterior (PA) mobilization is a non-invasive treatment method traditionally used to treat low back pain (LBP) in many countries. However, the effects of PA mobilization on lumbar spine biomechanics are still unknown. The aim of this study is to determine the maximum von Mises stresses on the lumbar vertebra (L5), with force applied at different angles during PA mobilization therapy using finite element analysis (FEA). Methods: L5 vertebra CT images of a 30-year-old male patient were modeled in three dimensions (3D) with MIMICS software to examine the PA mobilization biomechanics. The resulting L5 spine model was submitted to the finite element software ANSYS (version 19) to evaluate the effects of PA mobilization. To simulate PA mobilization on the L5 vertebra, a static force of 100 N was applied over the spinal process in three different directions. The distribution of von Mises stresses occurring in the L5 spine was determined in the analyses. Results: During PA mobilization, the stress distributions on the vertebrae caused by the static force applied in three different directions in the L5 vertebra spinal process was determined. As a result of the analysis, higher stress values were found in the posterior elements of the vertebrae in all directions compared to the vertebral corpus. However, when compared according to the direction of application, the lowest stress values were detected in the pedicles and laminas in PA mobilization applied toward the spine center. Conclusion: Vertebral pedicles, laminae, and spinous process are critical areas prone to fracture. It was argued that the change in the direction of PA mobilization applied in the L5 vertebral spinal process affects the von Mises stress distributions occurring in the pedicles and laminae.