Dependent coordinates in the Lagrange-Poincar\'e equations for   mechanical systems with symmetry
  The Lagrange--Poincar\'e equations for the mechanical system describing the motion of a scalar particle on a Riemannian manifold with a given free and isometric action of a compact Lie group is obtained. In an arising principle fibre bundle, the total space of which serves as a configuration space of the considered mechanical system, the local description of the reduced motion is done in terms of dependent coordinates. In obtaining of the equations we use the variational principle developed by Poincar\'e for the mechanical systems with a symmetry. 
S. N. Storchak
math-ph hep-th math.MP