Functional pain. It does not necessarily have to be nociception

Pain caused by dysfunction cannot be explained only by the activation of the nociceptor system and reflective interactions in the spinal cord. Clinical findings indicate that dysfunction produces pathologic afferent patterns without any stimulation of nociceptors which can be interpreted as pain in the central nervous system without participation of the nociceptor system. Functional pain seems to have an aspect of software, which cannot be analysed by hardware-oriented methods and it could, therefore, make sense to modify the design of clinical trials.