Kinesis (In-vivo/In-vitro) of L5-S1 lumbar spine

Low back pain is a spinal-related problem mainly caused by degenerative disc disease. Throughout the spine, the lumbar region is the most prone to the disease since it supports the upper torso by transmitting compressive and shearing forces to the lower body during everyday activities. The study focused on the bottom-most L5-S1 segment of the lumbar. The project was conducted by measuring the range of motion of the lumbar region through an in-vivo study as a preliminary research. The measurement utilises a skin-surface markers and motion capture cameras with computerised motion analysis to continuously record the changing range of motion and curvature of the spine. A design for the lumbar segment model was also created by utilising image processing and computer-aided engineering software to convert CT scan image into meshed finite element model. The preliminary result shows that the flexion, extension and axial rotation range of motion was different than the literature, which may have been caused by in-vivo factors such as fatigue, sway and other measurement variability. Due to the time constraints, the finite element model has yet to be fully analysed for its stress and load distribution. It is planned in post-graduate study that the model is to be driven with the preliminary range of motion result to be extensively analysed for its load and stress distribution.

I. Introduction

The spine is a flexible column that is formed from the back of the skull to the pelvis by a stack of bones known as vertebrae [1]. The thirty-three different vertebrae are interconnected with each other through intervertebral discs, endplates, muscles, flexible tendons and ligaments. The vertebrae column serves as a strong pillar and give support to the body, creating a shielded passageway for the spinal cords and nerves, and designed with muscle attachments for spinal motions. The vertebrae are numbered according to their regions: cervical (C1-C7), thoracic (T1-T12), lumbar (L1-L5), sacral (S1-S5) and coccyx.