A general inverse dynamic model is presented that is applicable to mechanisms incorporating member, joint and base compliance. Previous approaches for defining inverse dynamic models of compliant mechanisms have been approximations or limited to simple mechanism geometries and open-chain mechanisms. Hence, the motivation for a more general approach. Inverse dynamic equations for compliant mechanisms modeled with and without constraint equations are shown to be solvable sets of differential/algebraic equations (DAE’s); relevant characteristics and solutions of DAE systems are discussed. An important application for inverse dynamic models of compliant mechanisms is model-based force control of closed-chain mechanisms. The formulation and solution procedures discussed in this paper have been successfully applied to model legged locomotion on natural terrain.