Table 1 Definitions of Common Conditions or Processes Contributing to Low Back Pain 21 , 22 , 33
Nociceptive pain Pain from nociceptor activation in response to actual or threatened damage to non-neural tissue
 Discogenic pain Pain from nociceptive signaling within the intervertebral disc
 Myofascial pain Pain from nociceptive signaling from within muscle or fascial tissues that may or may not include referred pain or the presence of trigger points
 Sacroiliac joint pain Pain from nociceptive signaling within and surrounding a sacroiliac joint(s)
 Zygapophyseal (facet) joint pain Pain from nociceptive signaling within and surrounding a zygapophyseal (facet) joint(s)
Neuropathic pain Pain caused by a lesion or disease of the somatosensory nervous system
 Radicular pain Pain from ectopic activation of nociceptive afferent fibers in a spinal nerve or its roots, or from other neuropathic mechanisms (eg, inflammation, tensile strain)
 Radiculopathy Objective sensory and/or motor function loss caused by conduction block in axons of a spinal nerve or its roots
 Neurogenic claudication Pain from intermittent compression and/or ischemia of a single or multiple nerve roots within an intervertebral foramen or the central spinal canal
Peripheral neuropathic pain Pain from inflammation, compression, or entrapment of peripheral nerves in the lumbar region
 Piriformis syndrome Pain from inflammation, compression, and/or entrapment of the sciatic nerve in the vicinity of the piriformis muscle
 Thoracolumbar syndrome Pain from cluneal nerve entrapment causing low back and/or lower extremity symptoms
Sensitization Increased responsiveness of nociceptive neurons to their normal input, and/or recruitment of a response to normally subthreshold inputs
 Central sensitization Increased responsiveness of nociceptive neurons in the central nervous system to their normal or subthreshold afferent input
 Peripheral sensitization Increased responsiveness and reduced threshold of nociceptive neurons in the periphery to the stimulation of their receptive fields