Frequency dependent properties and pelvis parameter identification

Biological structures are known to show different rigidities when subjected to tensile tests at different strain rates. It is therefore justified to suspect a frequency dependency of the biomechanical properties in dynamic tests as well. In the frame of our research on Low Back Pain, a model of the human pelvis and a dedicated identification method are being developed. The purpose of this study is to investigate the influence that a dependency in frequency of the dynamic properties of the human pelvis can have on its parameters identification. In order to get an idea on the significance of this influence, simulated measurements based on frequency dependent models are fed in identification tools, which assume frequency independent properties. The results show that the identification e±cacy is impaired, suggesting the importance of the implementation of a frequency dependency in the identification method.