In this paper, an approach that enables one to investigate and to reduce the mechanical couplings between the manipulator links is proposed. The presented method is based on equations of motion expressed in terms of the normalized quasivelocities (NQV) introduced originally by Jain and Rodriguez (1995, “Diagonalized Lagrangian Robot Dynamics
,” IEEE Trans. Rob. Autom., 11, pp. 571–584). As a result, some observations and an algorithm which can be used at the design step of manipulators are done. Moreover, it is shown that for a rigid manipulator a class of integrable desired trajectories of the NQV can be given. The presented strategy was tested by simulation on a 3 DOF spatial manipulator.