A method of providing stimulation therapy to a patient includes performing first and second calibration processes in first and second patient posture states, respectively. The first and second calibration processes respectively associates a sensation experienced by a patient, in the respective patient posture states, with first and second amounts of an evoked potential, respectively, and also with first and second values of a stimulation parameter to achieve the first and second amounts of evoked potential, respectively. Thereafter, a current patient posture state is detected. If the current patient posture state is detected as the first patient posture state, stimulation therapy is applied to the patient using the first value of the stimulation parameter as an initial value. If the current patient posture state is detected as the second patient posture state, stimulation therapy is applied to the patient using the second value of the stimulation parameter as the initial value.
