Theoretical Model of the Lumbar Spine Musculature

The complexity of the spine makes an entire understanding of its mechanical function difficult, particularly since the stresses and strains can't be measured directly with non-invasive techniques. To explain the behaviour of the spine and its various components, biomechanical models are used where in-vivo studies are impractical. All biomechanical models of the spine share one common feature; each must contains an anatomical model of the spine and a way of distributing force to the components during this anatomical model. There's little consistency between previous anatomical models with authors incorporating different numbers of muscles, using different measures of muscle area (physiological cross-sectional area (PCSA) or cross-sectional area (CSA)), grouping muscles differently with reference to activation and using values between 30 N cm-2 and 100 N cm-2 for the utmost muscle force intensity. Most of those differences stem from a scarcity of detailed anatomical information for the muscles of the lumbar spine.