Prevention of cervical spine injuries will be helped by the construction of accurate mathematical models of the cervical spine. These models can be used to test varying loading conditions incorporating protective systems designed to reduce injury severity. Detailed material constitutive formulations for the soft tissue structures of the spine in combination with the precise anatomical soft tissue geometry have bee  obtained for a limited number of spine specimens. Injury prevention effective over the whole population would be aided by specific models that represent each of the numerous age, size, and gender groups. Since spine properties vary widely among individuals, this approach could offer benefits over models assembled from portions of data from a variety of non-homogeneous sources. This would require an extraordinary amount of experimental data. Efficient testing methodologies, which improve the utilization of testing resources, would be of great benefit to such an effort.

This study is designed to establish an efficient in vivo cadaveric biometrical experimental model of the spine as a method capable of quantifying both the gross structural properties of multiple and single motion segments of the spine and the structural and material properties of the constraining soft tissue for a single specimen. This information will then be available for incorporation into spinal models.
Briefly, vertebral bodies will be loaded in all directions and axes in both positive and negative directions in a load control mode. The motion of the bodies will be recorded during the applied loading. Individual elements will be removed from the motion segment and the attachment areas of all soft tissue will be digitized as testing proceeds. After each removal, the motion recorded for the intact specimen will be applied in a position control mode. Using the principle of superposition, the contribution of each structure for each loading direction can be precisely determined. Using the insertion site coordinate information, the elongation of the soft tissues for the measured motion can be calculated. The non-linear load-deformation relationships to these structures can then be calculated.

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