“…Isotropic poroelasticity theory has been used for many years to analyze wave propagation in cancellous bone (Williams, 1992;Otani, 1997, 1998;Haire and Langton, 1999;Kaczmarek et al, 2002;Fellah et al, 2004;Wear et al, 2005;Pakula et al, 2008;Fellah et al, 2008;Sebaa et al, 2008;Cardoso et al, 2008), and just recently the role of microarchitecture has been included in poroelasticity theory through the fabric tensor (Cowin and Cardoso, 2011). Most clinical ultrasound densitometers depend on empirical relationships between the speed of sound (SOS), broadband ultrasound attenuation (BUA), and bone density in order to assess bone loss.…”