In this research, in order to achieve Pinpointed Muscle Force Control (PMFC) in lower limb, we developed lower limb musculoskeletal model and use the model for calculation and control one or some selected target muscles force. PMFC is the method which can be expected the effect to rehabilitation or training by giving a stimulus to the particular muscle. In the developed model, one leg has 4 links, 7 degrees of freedom (DOFs) and 44 major muscles. This model can estimate the muscle forces by using the optimization method. Some external force which the selected muscle generates target muscle force are obtained by using this model. The validation is taken by comparing change rate of the estimated muscle force with change rate of electromyogram (EMG) of the muscle obtained from experiments. We validate effectiveness of this model and the PMFC in lower limb by result of experiments.