Techniques for determining the trajectory of a one or more dorsal roots and utilizing the trajectories to improve a spinal cord stimulation model are disclosed. A first improvement constructs a target stimulation field along a path that is parallel with the determined trajectory that is nearest to a specified desired location of stimulation. An allocation of stimulation among the electrodes to mimic the target field is computed. A second improvement models a response of neural elements at evaluation positions that are parallel with the trajectories based on the electric field that is generated for the computed allocation of stimulation among the electrodes. The stimulation amplitude is adjusted based on the neural element modeling to maintain stimulation intensity, and the stimulation amplitude and allocation of stimulation among the electrodes are compiled into an electrode configuration that is communicated to a neurostimulator.
