Distribution of intervertebral compression and shear forces in the cervical spine during isometric tasks

44th Congress of the Société de Biomécanique, Poitiers, France, 28-/10/2019 - 30/10/2019; Task related estimation of the musculo-tendon and intervertebral forces in the neck can help gaining some insights on the role of the central nervous system and in assessing cervical spine disorders. Musculoskeletal models have been developed to solve the muscular redundancy and estimate these forces, generally based on a static equilibrium computed at the level of the C4/ C5 joint, e.g., (Moroney et al. 1988; Van den Abbeele et al. 2018). However, solving the equilibrium of the entire cervical spine system is essential to be able to evaluate its muscular response (including from its numerous multi-level muscles) as well as the loads transmitted to the vertebrae and inter-vertebral discs. This study investigates the distribution of the intervertebral compression and shear forces in the cervical spine during two isometric maximum voluntary contractions (MVC) tasks, toward neck flexion and extension. The forces at the C4/C5 joint and the musculo-tendon forces of 8 muscle groups are compared with the results of two other neck models reported in the literature.