On a micromorphic model for the synovial fluid in the human knee

In this paper, an alternative model for the synovial fluid in the human knee is proposed. The synovial fluid is modeled as a micromorphic fluid containing deformable material particles with 12 degrees of freedom, namely three translations, three rotations and six stretches and shears. Two micromorphic viscosity coefficients are introduced as functions of hyaluronan and PRG4/lubricin concentrations and are reconstructed by a genetic algorithm based on experimental data. The model is validated by applying it to well established rheological measurements of synovial fluid, such as shear-thinning (Cooke et al., 1978).