title: Effect of hydration on the frequency-dependent viscoelastic properties of articular cartilage.
abstract: The aim of this study was to determine the effect of tissue hydration on the frequency-dependant viscoelastic properties of articular cartilage. Such changes were determined at frequencies associated with normal (1-10 Hz) and impulsive/traumatic (90 Hz) heel-strike times. Cartilage on bone samples, obtained from bovine humeral heads, was tested when hypo-hydrated and hyper-hydrated using dynamic mechanical analysis. Dynamic mechanical analysis was performed at a range of frequencies between 1 and 90 Hz. Hypo-hydration increased the stiffness of cartilage as compared to hyper-hydrated cartilage; this increase was greater at higher frequencies. The storage modulus and stiffness increased in hypo-hydrated cartilage as compared to hyper-hydrated cartilage. However, the loss modulus and stiffness increased when cartilage was hypo-hydrated as compared to hyper-hydrated, but these increases were not frequency dependent. An impulsive heel-strike time may result in a greater increase of stiffness in hypo-hydrated cartilage, compared with hyper-hydrated cartilage. However, the ratio of storage to loss stiffness was greater for hyper-hydrated cartilage, thereby, reducing the tissue's ability to dissipate energy and increasing the likelihood of cartilage rupture.
authors: College of Medicine, Swansea University, Swansea, UK.
authors: Benjamin
authors: B
authors: Pearson
authors: Daniel M
authors: DM
authors: Espino
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000737:chemistry* / Q000502:physiology*; D002417:Cattle; D004548:Elasticity; D058430:Humeral Head / Q000737:chemistry / Q000502:physiology; D014783:Viscosity; D014867:Water
chemical_list: D014867:Water
keywords: Biomechanics; biomechanical testing; cartilage; dynamics