Background: Multifdus muscle (MF) is one of the back muscles of the spine that is involved in the pathogenesis of low back pain. Its role as a stabilizer of the spine continues to present diagnostic and therapeutic challenges. The degree of MF degeneration is dependent on multiple clinical and radiological factors. We proposed a new equation to predict MF degeneration based upon clinical and radiological changes in magnetic resonance imaging. Methods: Clinical factors associated with MF degeneration include visual analogue scale (VAS) for pain, body mass index, duration of complaint, age of the patients and the presence of sciatica. Other radiological factors include the number of disc pathologies, neural canal stenosis and facet joint arthropathies, by building a module of a univari- ate and multivariate linear regression analysis for the parameters afecting MF degeneration score as a dependent variable. Results: Regarding the univariate and multivariate linear regression for factors afecting MF degeneration, the most common factors associated with increased multifdus score were the duration in years and VAS score in the multi- variate analysis model with B value equal to 0.184 according to duration in years and equal to 0.287 with VAS score according to 95% confdence interval. Conclusion: The equation for multifdus score is a helpful method to predict the degree of MF degeneration in rela- tion to clinical variable.