Picture of two heads

Open Access research that challenges the mind...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including those from the School of Psychological Sciences & Health - but also papers by researchers based within the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

The internal mechanics of the intervertebral disc under cyclic loading

Riches, P.E. and Dhillon, N. and Lotz, J. and Woods, A.W. and McNally, D.S. (2002) The internal mechanics of the intervertebral disc under cyclic loading. Journal of Biomechanics, 35 (9). pp. 1263-1271. ISSN 0021-9290

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

The mechanics of the intervertebral disc (IVD) under cyclic loading are investigated via a one-dimensional poroelastic model and experiment. The poroelastic model, based on that of Biot (J. Appl. Phys. 12 (1941) 155; J. Appl. Mech. 23 (1956) 91), includes a power-law relation between porosity and permeability, and a linear relation between the osmotic potential and solidity. The model was fitted to experimental data of the unconfined IVD undergoing 5 cyclic loads of 20 min compression by an applied stress of 1 MPa, followed by 40 min expansion. To obtain a good agreement between experiment and theory, the initial elastic deformation of the IVD, possibly associated with the bulging of the IVD into the vertebral bodies or laterally, was removed from the experimental data. Many combinations of the permeability-porosity relationship with the initial osmotic potential (πi) were investigated, and the best-fit parameters for the aggregate modulus (HA) and initial permeability (ki) were determined. The values of HA and ki were compared to literature values, and agreed well especially in the context of the adopted high-stress testing regime, and the strain related permeability in the model.