A new nonlocal hydrodynamic approach to describe structured media is developed.According to this approach the nonlocal and spin properties of a medium are closely correlated.The concrete kind and scale of the medium structure resulting from the strain process are definedby the initial and boundary conditions in a nonunique way due to the branching of solutions to thenonlinear problem. As a consequence, in the same medium localization of the strain process canbe realized either in the form of shear banding or rotational motion. As a test task the well-knownRayleigh problem on nonsteady motion of a plate in viscous media is solved to show that thedegree of nonlocality is proportional to acceleration of the plate. The solution obtained is thenused to explain experimental results on shock-induced shear bands and vortex structures inmetals.