Determining the effect of hydration upon the properties of ligaments using pseudo Gaussian stress stimuli.

The level of tissue hydration is known to effect viscoelastic material properties. However, prior studies have not fully investigated the effect of hydration on dynamic behavior nor compared the results of transient and dynamic behavior. The material properties of medial collateral rat knee ligaments were studied in relation to hydration, using (sequentially) 0.

Rat cutaneous RA afferents activated by two-dimensional skin stretch.

Skin develops biaxial stresses and strains when stretched. Rapidly adapting cutaneous mechanoreceptor neurons are known to be stretch sensitive, yet in the past, they have been studied using stretch stimuli applied along only a single direction. In this study, cutaneous rapidly adapting mechanoreceptors were studied in preparations of isolated skin in which the skin was stretched dynamically using biaxial stretch stimuli and in which loads and displacements were measured along two directions.

Stretch sensitivity of cutaneous RA mechanoreceptors in rat hairy skin.

Twenty-five rapidly adapting mechanoreceptor afferents were recorded in an in vitro preparation of rat skin and nerve. Single units were recorded while the skin was subjected to dynamic uniaxial stretch using a pseudo-Gaussian noise (PGN) input waveform. Force was the controlled variable in stretch stimuli.

Three-dimensional load analysis of indentation stimulators.

The properties of three types of indentation stimulators: filament indenters, a spring gauge indenter, and an electromechanical stimulator, were evaluated by actuating each device against a 3-direction load cell. The on-axis loads produced by filament indenters were independent of the degree of buckling. The off-axis loads produced by a filament increased with the degree of buckling of the filament, and had magnitudes that were up to 25% of the on-axis load.