  Changing the set of independent variables of Poincare gauge theory and
considering, in a manner similar to the second order formalism of general
relativity, the Riemannian part of the Lorentz connection as function of the
tetrad field, we construct theories that do not contain second or higher order
derivatives in the field variables, possess a full general relativity limit in
the absence of spinning matter fields, and allow for propagating torsion fields
in the general case. A concrete model is discussed and the field equations are
reduced by means of a Yasskin type ansatz to a conventional Einstein-Proca
system. Approximate solutions describing the exterior of a spin polarized
neutron star are prsented and the possibility of an experimental detection of
the torsion fields is briefly discussed.
