1. A method comprising: monitoring a plurality of signals, each of the signals generated by a sensor as a function of at least one of activity or posture of a patient; periodically identifying a posture of the patient based on at least one of the signals; associating each of the identified postures with a therapy parameter set currently used by a medical device to deliver at least one of a movement disorder therapy, psychological disorder therapy, or deep brain stimulation to the patient when the posture is identified; periodically determining an activity level of the patient based on at least one of the signals; associating each of the determined activity levels with a therapy parameter set currently used by a medical device to deliver the at least one of the movement disorder therapy, psychological disorder therapy, or deep brain stimulation to the patient when the activity level is determined and a current one of the periodically identified postures; and for each of a plurality of therapy parameter sets used by the medical device to deliver the at least one of the movement disorder therapy, psychological disorder therapy, or deep brain stimulation to the patient to the patient, determining a value of an activity metric for each of the periodically identified postures associated with the therapy parameter set based on the activity levels associated with the posture and the therapy parameter set.