Human character animation has problems of unrealistic motion and unrealistic skin deformation. In this study, we present an application of motion capture data for generating realistic human character animation using anatomically correct skeleton and muscle models. For this purpose, we attach a skeleton model to the motion data and then construct and attach a set of muscle models to the underlying skeleton. Deformation under isotonic contractions are modeled using a number of geometric primitives. As a result, we have implemented a toolkit where animations can be viewed and recorded as a video file. In order to demonstrate the use of the toolkit, we have produced a number of short movies for entertainment purposes. The generated muscle deformations are realistic. As future work, we plan to apply skin to our model and generate realistic looking skin deformations.