Musculo-tendinous stiffness of head-neck segment in the sagittal plane: An optimization approach for modeling the cervical spine as a single-joint system

作者：Portero Raphael; Quaine Franck^*; Cahouet Violaine; Thoumie Philippe; Portero Pierre

来源：Journal of Biomechanics, 2013, 46(5): 925-930.

DOI：10.1016/j.jbiomech.2012.12.009

• Musculo-tendinous stiffness
• Head-neck segment
• Head kinematics
• Multi-joint segment
• Cervical muscles

Despite the multi-linked architecture of the cervical spine, all previous studies that have made estimations of mechanical properties of the neck have considered the head-neck segment as a rigid link, with a fixed center of rotation at C7. The aim of this study was to consider the head-neck segment as a changeable geometry system for locating the resultant center of rotation and for calculating the musculo-tendinous stiffness by the quick-release method. Head kinematics during quick-releases was analyzed by recording the trajectory of surface markers. With an optimization procedure, the position of the resultant center of rotation of the head-neck segment was estimated. Thereafter, the angular displacement and acceleration of the head, together with the isometric torque developed by the cervical muscles were used to calculate the segment%26apos;s stiffness. The results showed a consistent center of rotation and a significant increase of the musculo-tendinous stiffness with increasing torque.