This paper discusses a general parameterization of the ″moving″ surface where the pressure is applied, which is constructed by exploiting the isoparametric finite element concept. It also examines the specific application of the methodology to the axisymmetric case which appears not to have been considered previously in the literature. A summary is given of the basic notation employed in this paper, along with some necessary background. The construction of the proposed parameterization is undertaken, and the application to the axisymmetric case along with a numerical example that illustrates the methodology is considered.