Biomechanical effects of altered multifidus muscle morphology on cervical spine tissues

In this study, we constructed the morphology of the multifidus muscle to more realistically simulate the mechanical environment of the cervical spine <i>in vivo</i> and quantitatively explored the effects of multifidus muscle atrophy on cervical spine tissues. The results showed that volume atrophy of the multifidus muscle altered the mechanical response of cervical spine tissues. Volume atrophy of the multifidus muscle significantly increased the mechanical indexes of the cervical spine tissues, in which the cervical disc stresses, joint capsule strains, and cartilage endplates increased significantly. Compared with the mechanical changes in the upper cervical segments, the mechanical changes in the lower cervical segments were higher. Therefore, it is important to moderately increase the functional exercise of the multifidus muscle to prevent atrophy leading to abnormal stress concentrations in cervical tissues.