  We prove constructive estimates for elastic plates modelled by the
Reissner-Mindlin theory and made by general anisotropic material. Namely, we
obtain a generalized Korn inequality which allows to derive quantitative
stability and global H^2 regularity for the Neumann problem. Moreover, in case
of isotropic material, we derive an interior three spheres inequality with
optimal exponent from which the strong unique continuation property follows.
