Multi-polar stimulation protocols have been used in the past to increase the selectivity of electrical stimulation of the nervous system. Nonetheless, the number of possible multipolar stimulation protocols is prohibitively large and cannot be explored during in vivo experiments. Computational models allow to test a large number of stimulation protocols and to determine the most selective ones in silico. The evaluation of the selectivity of one stimulation protocol relies on the understanding of the functional organization of the nerve, which is normally determined ex-post, from cadaveric analyses. Here, we propose a simple method to use recruitment curves to determine a putative location of the groups of motor fibers targeting different muscles in a nerve, and show that this information can allow the determination of optimal stimulation protocols on the original fiber populations.