Construction and validation of a three-dimensional trunk musculoskeletal model by using data from Computed Tomography (CT) and Magnetic Resonance Imaging (MRI)

Abstract

In this study, we constructed a novel three-dimensional trunk musculoskeletal model that included thoracolumbar intervertebral using data from computed tomography (CT) and magnetic resonance imaging (MRI). Characteristics of the model are as follows. Firstly, the thoracolumbar structure was modeled in detail (i.e., skeleton, muscle paths and muscle cross-section areas) from CT and MRI data. Secondly, new factors were included in this model such as intra-abdominal pressure and physiological trunk range of motion to calculate internal biological forces more accurately than in previous models. Thirdly, this musculoskeletal trunk model is an aid to analyzing dynamic motion. The aims of this study was to analyze detailed three-dimensional motion in healthy adults using this model, and to estimate internal biological forces, including spinal moment and muscle force in a standing position. The validation of this model used the calculated intradiscal pressure for the L4/L5 disc according to previous reports. This model is able to analyze spinal moments and trunk muscle force during static motions. The present study confirms that the moment curve of spinal can be generalized in the various postures. The model has been validated, and was able to analyze three-dimensional motion (i.e., combinational factors of rotation and flexion). As a result, this model is expected to have clinical applications.