Local torque minimization for redundant manipulators has been consider
ed by using a redundancy resolution approach. Since its initial formul
ation, however, proposed solutions have been plagued by performance in
stabilities. Till now, the reason was not clear. In this paper it is s
hown that the instability problem occurred because of incorrect formul
ation. A correct formulation is proposed, which is used to analyze the
reason for instability. Special attention is paid to joint accelerati
on terms at the selfmotion manifold. This helps explaining the recent
formulation of a stable scheme based on local joint velocity minimizat
ion in terms of torque. The results obtained are related to dynamic re
dundancy resolution in general.