Structural flexibility of biomolecules is closely coupled to function, as evidenced by many conformational changes observed on key cellular process. We actively work to effectively address the study and simulation of the dynamics of macromolecular systems with Normal-Mode Analysis (NMA), geometric algebra and other multiscale approximations. Following the basic principle if you know how it moves, you can infer how it works; the knowledge of structural flexibility offers a straight-line connection between structure and function. Thus, inferring the intrinsic molecular flexibility from a single conformation could offer a direct link to understand likely large scale rearrangements. We address this problem by exploring novel multiresolution approaches to simulate the dynamics of protein, nucleic acids and their complexes. If your are interested you can play with iMOD, our versatile toolkit to perform Normal Mode Analysis (NMA) in internal coordinates or directly in our iMODS online server.