Abstract: Physical realism plays an important role in the way character animations are being perceived. We present a method for evaluating the physical realism of character animations, by using musculoskeletal model simulation resulting from biomechanics research. We describe how such models can be used without the presence of external force measurements. We define two quality measures that describe principally different aspects of physical realism. The first quality measure reflects to what extent the animation obeys the Newton-Euler laws of motion. The second quality measure reflects the realism of the amount of muscle force a human would require to perform the animation. Both quality measures allow for highly detailed evaluation of the physical realism of character animations.