title: The nonlinear viscoelasticity of hyaluronic acid and its role in joint lubrication.
abstract: Hyaluronic acid solutions have been widely studied due to their relevance to the rheological behavior of synovial fluid and joint lubrication. Ambulatory joint motion is typically large oscillatory deflections; therefore, large amplitude oscillatory shear strain experiments are used to examine the relevant non-linear viscoelastic properties of these solutions. Using the sequence of physical processes method to analyze data provides time dependent viscoelastic moduli, which exhibit a clear physiologically relevant behavior to hyaluronic acids non-linear viscoelasticity. In particular, it is seen that during peak strain/acceleration, the time dependent elastic modulus peaks and the loss modulus is at a minimum. The hyaluronic acid can provide an immediate elastic response to sudden forces, acting like a shock absorber during sudden changes in direction of motion or maximum deflection. However, during peak rate, the elastic modulus is at a minimum and the loss modulus is at a maximum, which provides greater efficacy to hydrodynamic shear lubrication.
authors: Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79409, USA. gchristo@ttu.edu.
authors: Zhenhuan
authors: Z
authors: Zhang
authors: Gordon F
authors: GF
authors: Christopher
mesh_terms: D004548:Elasticity; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism*; D007717:Knee / Q000502:physiology; D008954:Models, Biological; D009068:Movement; D017711:Nonlinear Dynamics; D012212:Rheology; D013314:Stress, Mechanical; D013582:Synovial Fluid / Q000378:metabolism*; D013997:Time Factors; D014783:Viscosity
chemical_list: D006820:Hyaluronic Acid