Repeated End-Range Spinal Testing

Ron Donelson

Updated 4/2015

Determining a precise diagnosis is the crucial first step in successfully managing any patient’s complaint. But how “precise” does a diagnosis need to be?

According to one health care innovation expert, a diagnosis remains imprecise until it identifies a standardized, predictably effective treatment that addresses the cause and not just the symptom.1 Obviously, identifying that level of precision represents tremendous value. Unfortunately, in spine care, the most reliable and accurate anatomic diagnosis - a herniated disc causing sciatica, neural deficit, and concordant imaging findings - only applies to a small percentage of patients. More importantly however, even that excellent anatomic diagnosis falls short of identifying a standardized treatment. Typically, it is the background of the provider the patient chooses that typically determines the treatment, with great variability across providers.

Fortunately, there is a method of clinical evaluation that enables making a mechanical rather than an anatomic diagnosis. A mechanical diagnosis is identified by having each patient perform standardized sets of spinal test movements consisting of repeated spinal bending tests in different directions.2 By monitoring for common patterns of pain response during the testing, one can determine common mechanical characteristics of the underlying pain-generator which then identifies the mechanical diagnosis.

The most common pattern of pain response is called “pain centralization” where pain that has spread away from the mid-line of the neck or low back, sometimes all the way to the hand or foot, is moved back toward the spine during one single direction of spinal bending testing before it disappears entirely. That single direction of beneficial testing is known as the pain-generator’s “directional preference”. Treatment with matching directional exercises has been shown in many studies to be very effective in bringing about full recovery, often in a very short period of time - see "Non-Surgical Treatment: Directional Exercises”.

When individuals with back or neck pain for less than one month, including pain radiating into the lower arm or leg, are examined in this way, studies have reported that 70-89% of patients will have a single direction of end-range spinal bending tests that centralizes and very often abolish all the pain.6-9 Again, that beneficial direction of testing is called the pain-generator’s “directional preference” while the opposite direction of testing typically intensifies or even sends the pain further away from the spine, called “peripheralization of the pain. That direction of worsening pain represents the disorder’s “directional vulnerability”.10 These directional patterns are often first detected in the patient’s history as they report what movements, positions, and activities make their pain better or worse. Of further value, a directional preference is also found in 50% or more of chronic patients, including those considered to be candidates for some form of disc surgery.12-15

A directional preference directly reflects important characteristics of the actual pain-generator. It is first mechanical but, more importantly, it’s also reversible.11 That means that bending the spine in one direction improves the pain while the opposite direction makes it worse. The name of the “mechanical” diagnosis for this directional pattern is a “reducible derangement”,2 meaning one direction of bending likely moves something out-of-position, causing, increasing, or peripheralizing the pain, while the opposite direction moves it back to, or toward, its normal position, thus centralizing or eliminating the pain. These changes in pain location have been tied in several studies to positional changes associated with painful disc disorders.

This mechanical diagnosis is usually confirmed within days as patients report their success in controlling and then eliminating their pain at home and at work using the directional exercises they learn that match their mechanical evaluation findings. Multiple studies document that most patients with a directional preference report a good-to-excellent recovery, often within 1-2 weeks, using directional exercises and postural modifications6-9 (See and "Non-Surgical Treatment: Directional Exercises”). Patients’ experiential education when eliminating their own pain by correcting the underlying reducible derangement typically also empowers them to prevent its return, both short- and long-term, enabling their progressive return to all their activities.

Two important points: 1-these rapid and simple recoveries whenever a directional preference is found are achievable without the need to make an anatomic diagnosis; 2-this is the only form of assessment capable of determining whether or not the underlying pain source, known or unknown, can be rapidly reversed or not, and how to reverse it.

These mechanical methods of spinal pain management are known as “Mechanical Diagnosis & Therapy”. The McKenzie Institute certifies practitioners in this technique.


  1. Christensen C. The innovator's prescription: a disruptive solution for health care. New York, New York: McGraw-Hill; 2009.

  2. McKenzie R, May S. Mechanical Diagnosis and Therapy. Second ed. Waikanae, New Zealand: Spinal Publications New Zealand Ltd.; 2003.

  3. Clare H, Adams R, Maher C. Reliability of McKenzie classification of patients with cervical and lumbar pain. J Manip Phys'l Ther. 2005;28(2):122-7.

  4. Kilpikoski S, Airaksinen O, Kankaanpää M, Leminen P, Videman T, Alen F. Interexaminer reliability in low back pain assessment using the McKenzie method. Spine. 2002;27:E207-14.

  5. Razmjou H, Kramer J, Yamada R. Inter-tester reliability of the McKenzie evaluation of mechanical low back pain. J OrthoSportsPTher. 2000;30(7):368-83.

  6. Donelson R, Silva G, Murphy K. The centralization phenomenon: its usefulness in evaluating and treating referred pain. Spine. 1990;15(3):211-13.

  7. Karas R, McIntosh G, Hall H, Wilson L, Melles T. The relationship between non-organic signs and centralization of symptoms in the prediction of return to work for patients with low back pain. Physical Therapy. 1997;77(4):354-60.

  8. Sufka A, Hauger B, Trenary M, Hagan A, Lozon R, Martens B. Centralization of low back pain and perceived functional outcome. Journal of Orthopedics and Sports Physical Therapy. 1998;27(3):205-12.

  9. Werneke M, Hart DL, Cook D. A descriptive study of the centralization phenomenon. A prospective analysis. Spine. 1999;24(7):676-83.

  10. Donelson R, Grant W, Kamps C, Medcalf R. Pain response to repeated end-range sagittal spinal motion: a prospective, randomized, multi-centered trial. Spine. 1991;16(6S):206-12.

  11. Donelson R. Rapidly reversible low back pain: an evidence-based pathway to widespread recoveries and savings. Hanover, NH: SelfCare First, LLC; 2007.

  12. Donelson R, Aprill C, Medcalf R, Grant W. A prospective study of centralization of lumbar and referred pain: A predictor of symptomatic discs and anular competence. Spine. 1997;22(10):1115-22.

  13. Kopp J, Alexander A, Turocy R, Levrini M, Lichtman D. The use of lumbar extension in the evaluation and treatment of patients with acute herniated nucleus pulposus, a preliminary report. Clinical Orthopedics. 1986;202:211-8.

  14. Laslett M, Öberg B, Aprill C, McDonald B. Centralization as a predictor of provocation discography results in chronic low back pain, and the influence of disability and distress on diagnostic power. The Spine Journal. 2005;5:370-80.

  15. Rasmussen C, Nielsen G, Hansen V, Jensen O, Schioettz-Christensen B. Rates of lumbar disc surgery before and after implementation of multidisciplinary nonsurgical spine clinics. Spine. 2005;30:2469-73.