Centralization versus peripheralization of symptoms, is a concept or idea that has been used in physical therapy and rehab settings for years. If you have been to a rehab specialist you may have heard these terms discussed before. But what do these terms mean?
Centralization and peripheralization is a theory on pain manifestation or a pain pattern originating from the spine. In general, when loading strategies become compromised for varies reasons, structures of the spine may become aggravated or irritated. As the stress continues the pain may be experienced in the low back. If the structures stay irritated and stress on the tissue increases the pain may become diffuse or larger in diameter. Symptoms may even move into the buttocks or lower leg. This is called peripheralization of symptoms.
Peripheralization of symptoms does not indicate that significant structural or tissue damage has occurred, rather the tissue is undergoing too much repetitive stress. Peripheralization is the first line of defense to let our body know that a change in activity or pattern of movement is needed. Many times, identifying contributing movement patterns that lead to deficiencies in spinal loading strategies can be affective in pain reduction. Creating variability in the loading strategies can lead to centralization of symptoms.
Centralization of symptoms occurs only after symptoms have begun to peripheralized. Centralization of symptoms is the phenomenon that occurs when the spinal tissue begins to experience less stress or strain. When tissue stress reduces, symptoms begin to “centralize” toward the low back. Leg pain will move to the buttocks, buttocks pain to the back and diffused pain in the back will move to the center of the spine. Centralization indicates a good prognosis!
Unfortunately, as symptoms centralize toward the low back, many times the pain intensity can slightly increase. This can be very misleading for patients and even medical professionals. Human nature tells us to avoid increasing pain on one’s body, so naturally patients may gravitate away from positions or activities that cause centralization as they may increase pain levels. Remember Centralization of symptoms must occur for proper tissue stress reduction to occur, if we avoid centralization we may never began to improve spinal loading deficiencies, and thus eliminate the problem.
The takeaway message: LOCATION, LOCATION, LOCATION!!! Where the pain is and more specifically where the pain is moving is much more important than intensity of pain! If a specific exercise or position moves the symptoms towards the back, that position is a positive position for spinal health even if the intensity of the pain increases slightly. Conversely, if a position or exercises increase symptoms away from your spine for more than 10 minutes, then it is a negative spinal loading strategy. In other words, how do your activities, spinal positions or exercises affect the location of pain.
*** Please note that intensity of symptoms should not be increasing dramatically, even if the symptoms centralize to the low back.
Many times, patients come in and note the pain is extremely variable, meaning pain moves up and down the leg frequently. Many view this symptom variability as a negative. Symptom variability when related to spinal loading dysfunction is a very good sign. Using centralization versus peripheralization, spinal loading strategies can be identified.
When treating patients, I always over simplify treatment, identify the good and bad loading strategies, avoid the bad, and do the good! If this is performed consistently over time, symptom reduction should occur. Ultimately, centralization gives the patient education, knowledge and direction regarding what a bad symptom is versus a good symptom!