We present a new method for analyzing the motion of the heart’s left ventricle (LV) from tagged magnetic resonance imaging (MRI) data. Our technique is based on the development of a new class of physics-based deformable models whose parameters are functions. They allow the definition of new parameterized primitives and parameterized deformations which can capture the local shape variation of a complex object. Furthermore, these parameters are intuitive and require no complex post-processing in order to be used by a physician. Using a physics-based approach, we convert the geometric models into dynamic models that deform due to forces exerted from the datapoints and conform to the given dataset. We present experiments involving the extraction of the shape and motion of the LV’s mid-wall during systole from tagged MRI data based on a few parameter functions. Furthermore, by plotting the variations over time of the extracted LV model parameters from normal and abnormal heart data along the long axis, we are able to quantitatively characterize their differences.