The intervertebral discs provide mobility and a degree of shock absorbance to the spinal column. It has been shown that the mechanical properties of the intervertebral discs play an important role in their functionality [1, 2]. While static models of the intervertebral disc have significance, dynamic models characterize more accurately the in situ nature of the tissues. Some researchers [3] have studied dynamic disc loading from the perspective of biomedical performance and fatigue failure. Other studies have reported on the viscoelastic properties of discs under high frequency vibration [4]. However, the authors did not find any study which used experimental modal analysis (EMA) and the receptance coupling (RC) method to extract the dynamic characteristics, i.e. stiffness, damping, and natural frequencies, of the intervertebral discs.
On the use of experimental modal analysis for system identification of a railway pantograph