The viscoelastic responses of the human cervical spine in torsion: Experimental limitations of quasi-linear theory, and a method for reducing these effects

• Published in: Journal of biomechanics Vol. 24; no. 9; pp. 811 - 817
• Main Authors: Myers, Barry S., McElhaney, James H., Doherty, Brian J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1991; Elsevier Science
• Subjects: Biological and medical sciences; Biomechanical Phenomena; Cervical Vertebrae - physiology; Computer Simulation; Elasticity; Fundamental and applied biological sciences. Psychology; Humans; Models, Theoretical; Space life sciences; Torsion Abnormality; Vertebrates: osteoarticular system, musculoskeletal system; Weight-Bearing - physiology; Biomechanics; Human; Viscoelasticity; Spine; Torsion stress
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/0021-9290(91)90306-8

The dynamic torsional viscoelastic responses of the human cadaver cervical spine were measured in vitro. The quasi-linear formulation of time dependent behavior was used to describe and predict the resultant torque as a function of applied angular deflection and time. The performance of the quasi-linear model was good, reaching correlation at the 99% confidence level; however, it tended to underestimate hysteresis energy (mean relative deviation = − 19.1%) and observed stiffness. This was in part due to difficulties in establishing the physical constants of the quasi-linear model from finite rate relaxation testing. An extrapolation deconvolution technique to enhance the experimentally derived constants was developed, to reduce the detrimental effects of finite rate testing. The quasi-linear model based on this enhanced derivation showed improved predictive ability and hysteresis energy determination.