A key issue in research about speech motor control is the one of the level of complexity that is required for the internal models: have these models to account accurately for all physical properties of the speech motor system, including the complex tongue-jaw biomechanics? Or would more simple internal representations be sufficient, which model only the static characteristics of the peripheral speech apparatus or which give a rough account of articulatory dynamics? On the basis of experimental and modeling studies of speech movements and human limb movements published in the literature, the adequacy of simplified internal representations for speech motor control is analyzed.