Papers Published

1. T. M. Best and J. H. Mcelhaney and W. E. Garrett and B. S. Myers, Axial strain-measurements in skeletal-muscle at various strain rates, Journal Of Biomechanical Engineering-transactions Of The Asme, vol. 117 no. 3 (August, 1995), pp. 262 -- 265 .
   (last updated on 2008/07/23)

   Abstract:
   A noncontact optical system using high speed image analysis to measure local tissue deformations and axial strains along skeletal muscle is described. The spatial resolution of the system was 20 pixels/cm and the accuracy was +/- 0.125 mm. In order to minimize the error associated with discrete data used to characterize a continuous strain field, the displacement data were fitted with a third order polynomial and the fitted data differentiated to measure surface strains using a Lagrangian finite strain formulation. The distribution of axial strain along the muscle-tendon unit was nonuniform and rate dependent. Despite a variation in local strain distribution with strain rate, the maximum axial strain, E(xx) = 0.614 +/- 0.045 mm/mm, was rate insensitive and occurred at the failure sire for all tests The frequency response of the video system (1000 Hz) and the measurement of a continuous strain field along the entire length of the structure improve upon previous noncontact optical systems for measurement of surface strains in soft tissues.