Mechanical force is routinely applied to proteins in force probing experiments and simulations to observe a protein's response to external stress. A yet unanswered question is how force propagates through proteins. How do perturbations like an external force flow through protein scaffolds and how is this related to protein stability and function?We here present a new method based on molecular dynamics simulations that allows visualizing stress propagation in proteins, resembling finite element analysis for macroscopic structures. Using this method we elucidate force distribution in I27, an immunoglobulin domain from human muscle titin and one of the most stable proteins known. Hereto we monitor alterations in forces between pairs of atoms in the folded state upon pulling the protein with a constant force. We find forces to be a more direct measure for internal strain than the only minor changes in atomic coordinates. We observe that the externally applied force is anisotropically distributed throughout the protein scaffold highlighting three prominent regions that contribute most of the protein's mechanical resistance.The functional relevance of the force distribution network is highlighted by unfolding simulations of in-silico mutants and, interestingly, by comparison with a network of coevolved residues found in the titin immunoglobulin family. Both networks show a remarkable overlap thereby suggesting that the force distribution pattern reflects evolutionary constraints used to render I27 a mechanically robust protein. We also show that the method can easily be extended to other types of perturbation including point mutations and allosteric signals, such as ligand binding or phosphorylation.