‘Lumbar syndrome’ or ‘non-specific low back pain’ is not a diagnosis but a description of a complaint or symptoms. It has no more validity than ‘knee syndrome’ or ‘non-specific elbow pain’ but has gained acceptance in the medical community through lack of confidence in traditional patho-anatomic diagnostic labels such as facet syndrome, sacroiliac and intervertebral disc lesions. The Quebec Task Force (QTF) on activity related spinal disorders (Spitzer, W.O. 1987) formally recognised that clinicians could not reliably differentiate between different patho-anatomic causes of back pain. They recommended a classification system that sidestepped the issue and concentrated on a simple method of classifying cases in a way that had prognostic utility. A summary of their classification system is given in Table 1. (Insert table 1 somewhere here, i.e. close to the reference in the text.) QTF classes 1 to 4 constitute 95% of all cases of spinal pain with or without radiation into the upper or lower limbs. It can be seen that no patho-anatomic diagnosis is assumed or proposed in these classes and that little training is required to differentiate between them. A simple history and neurological examination suffice to make the distinctions.

McKenzie R.A. (1981 & 1990) proposed another method (the McKenzie approach) of categorising patients with low back pain (LBP) (the McKenzie approach). His method consists of analysing symptomatic and mechanical responses to mechanical loading by repeated movements and sustained positions. He observed over many years that patients with spinal pain, with or without referred symptoms, react differently under the same mechanical loading conditions. Some improve with extension and worsen with flexion loading strategies, others improve and worsen with the opposite or mixed patterns, others again have pain provoked by certain movements but do not worsen when the movements are repeated, and there are those that are unaffected by movements. On the basis of these observations, McKenzie classified LBP patients into three mechanical syndromes (posture, dysfunction and derangement), nerve root entrapment, sacroiliac joint (SIJ) disorders, a category for other pathologies and a category ‘inconclusive’. Table 2 sets out a summary of his classification system. (Insert table 2 somewhere here.)

One category, the derangement syndrome, has a number of subcategories based on a conceptual model of dynamic disc mechanics and pathology. Preliminary evidence suggests that the McKenzie method of physical examination may be able to identify symptomatic disc pathologies in patients with chronic symptoms using provocation discography as the criterion standard to which it is compared (Donelson, R., Aprill, C., Medcalf, & R., Grant, W. 1997). Two other mechanical syndromes described by McKenzie, posture and dysfunction, do not imply any specific patho-anatomic disorder (with the exception of the adherent nerve root), but describe specific symptomatic and mechanical responses to the testing procedures. The McKenzie classification system has more clinical utility than the QTF system in that it directly leads to treatment aimed at resolving the patient’s symptoms. It also identifies those cases unlikely to respond to mechanically based therapies.

For a more complete discussion of the nature and structure of classification systems the reader is referred to the excellent discussion by Riddle, D.L. (1998) that applies a specific method of classification (Buchbinder, R., Goel, V., Bombadier, C. 1994) to various systems, including the QTF and McKenzie schemes.

What is the value of a classification system for low back and referred pain? This varies according to the author’s goal. In the case of the QTF, the goal was to standardise nomenclature, identifying groups of workers with activity related spinal pain with differing prognoses. This is of particular value to Government and other third party funding agencies whose primary concerns are with the rapidly increasing disability and cost of spinal pain in workers. McKenzie’s goal was to identify patients that respond to specific loading strategies, those that do not respond to mechanical treatment and those that should be referred for further medical assessment.

The purpose of this paper is to propose a new classification system based on a mixture of pathologic entities considered to exist and other categories that have diagnostic value and lead directly to treatment strategies. The proposed classification system assumes that the majority of acute and chronic low back pain cases have a pathologic basis for pain whether or not it is possible for diagnostic tests to identify the pathology in any given patient. The aim of this new system is to identify specific subgroups that may respond to specific treatments. The efficacy of these treatments can then be evaluated for the subgroup to which they are applied.

Since 1987 several studies on low back pain (LBP) patients have shown that it is possible to differentiate between symptomatic disc, zygapophysial joint (ZJ) and sacroiliac joint (SIJ) pathologies using skilled diagnostic injections. Discogenic pain as revealed by disc injection (provocation discography) is present in at least 39% of chronic LBP cases (Schwarzer, A.C., et al. 1995). Using strict criteria these cases are called ‘internal disc disruption’. Not all symptomatic discs satisfy these criteria and in reality the proportion of cases with discogenic pain will be higher than 39%. Diagnostic anaesthetic blocks have identified symptomatic ZJ’s in the lumbar spine (Jackson, R.P. 1992;, Schwarzer, A.C., et al. 1994a & 1994b). It is estimated that perhaps 15% of chronic LBP cases have symptoms directly attributable to the lumbar ZJ’s (Bogduk, N. 1995). The SIJ’s can also be a source of LBP (Dreyfuss, P., Michaelsen, M., Pauza, K., McLarty, & J., Bogduk, N. 1996,; Maigne, J-Y., Aivaliklis, & A., Pfefer, F. 1996,; Schwarzer, A.C., Aprill, & C.N., Bogduk, N. 1995). In one study diagnostic injections have identified symptomatic SIJ’s in 13% of cases of chronic LBP (Schwarzer, A.C., Aprill, & C.N., Bogduk, N. 1995). The studies referred to above are well conducted, follow strict criteria and satisfy rigorous scientific procedural requirements. The patients examined all fall into categories 1, 2 and 3 of the QTF classification system. In other words, they would come under the ‘non-specific LBP’ label. It is clear that 65 to 70% of these cases have specific identifiable pathologies (Bogduk, N. 1995).

However, Sstudies using diagnostic injections need to be interpreted with caution. While symptomatic intra-articular structures are targeted with diagnostic injections into the joints, extra-articular sources of pain associated with the joints are not influenced (Maigne, J-Y. et al. 1996). In addition, these studies have been carried out using patients with chronic symptoms. The prevalence of the various pathologic entities in acute and subacute patient populations may be quite different.

Some of the problems associated with using diagnostic injections as a basis for identifying subgroups within the ‘non-specific LBP’ spectrum are:

1. The great majority of clinicians and their patients do not have access to fluoroscopically controlled, contrast enhanced, diagnostic injection techniques.
2. There are relatively few doctors in the world that are skilled in, and can carry out, these procedures.
3. The procedures involve significant exposure to X-rays as well as injection of local anaesthetic and contrast material into the target structure.
4. The cost and invasive nature of these procedures make them suitable only for disabled patients without a clear diagnosis, possibly having chronic pain unresponsive to conservative care and being considered for surgery.

Recent research has demonstrated a mixture of results for a variety of commonly used treatments. Flexion exercises do not reduce sickness absence in acute low back pain (Faas, A., van Eijck, J.Th.M., Chavannes, A.W., & Gubbels, J.W. 1995). Standardized treatment methods using isolated lumbar strength testing and intense specific strengthening exercises based on progressive protocols using specific equipment can reduce pain, disability and reuse of health care services in chronic low back pain patients (Leggett, S., et al. 1999). ‘Active back school’ consisting of 20 sessions over 13 weeks, mixing education, back care advice, stretching and strengthening exercises, can reduce recurrences of new low back pain episodes and number of days of sick leave (Lønn, J.H., Glomsrød, B., Soukup, M.G., Bø, K., & Larsen, S. 1999). Active rehabilitation consisting of 24 one and a half hour sessions of graduated strengthening exercises over 12 weeks can reduce pain, functional disability and, to a lesser extent, fatigability (Kankaanpää, M., Taimela, S., Airaksinen, O., & Hänninen, O. 1999). Other studies report that exercises have only limited value (Faas, A. 1996,; Koes, B.W., Bouter, L.M., Beckerman, H., van der Heijden, & G.J.M.G., Knipschild, P.G. 1991). While there is some support for exercise therapies, the improvement over natural history is not impressive.

Manipulative therapies achieve short-term pain relief but no long-term reduction in recurrence rate or disability (Shekelle, P.G. 1994). Chiropractic and physiotherapy produce similar outcomes (Skargren, E.I., Carlsson, P.G., & Öberg, B.E. 1998). Chiropractic and a modified McKenzie approach are only slightly superior to a $1 educational booklet with regards to reducing disability (Cherkin, D.C., Deyo, R.A., Battie, M., Street, & J., Barlow, W. 1998). As demonstrated in an earlier study, the use of this booklet in addition to standard back care is not associated with improved outcomes (Cherkin, D.C., Deyo, R.A., Street, J.H., Hunt, M., & Barlow, W. 1998).

The results of these studies form the basis of recent government guidelines that de-emphasise specific disease targeted treatment in favour of non-specific treatment strategies such as analgesics, posture advice and "progressive reactivation" (National Advisory Committee on Health and Disability & Accident Rehabilitation and Compensation Insurance Corporation, 1997). Collectively these studies belie anecdotal evidence, (which is considered unreliable,) that patients with either acute or chronic low back pain experience a dramatic, rapid and lasting relief of pain and reduced disability from certain treatments. Dramatic improvements in symptoms and disability are common in new cases of acute low back pain with or without treatment, and anecdotal evidence is notoriously unreliable in these cases. However, in chronic back pain cases rapid improvement in response to treatment does occur and should be accounted for. How is it that these studies fail to identify those cases that do respond to specific treatments far better than what could be expected by chance or by resolution through natural history of the disease? Are these clinically observed successes just manifestations of chance confluence of beneficial psychosocial and placebo effects, or evidence of real treatment effects on specific pathologies?

Randomised clinical trials are useful in assessing efficacy of treatments in a general way but do not help the clinician with the individual patient. A treatment that has demonstrated benefit on average in a large group of patients may actually make a specific patient worse. What treatment should be offered for that patient? How is this patient different from those that do respond to the treatment that is successful?

One possible explanation for the negligible or modest benefit of non-specific treatments is that these studies include patients with all types of low back pain, regardless of the pathology. In other words, it seems that in these studies treatments are being applied to a wide spectrum of LBP pathologies. Each treatment studied has been administered to a patient population that includes pathologies not expected to benefit from that treatment method. For example, manipulation and repeated movements would not be expected to help inflammatory conditions or posture syndrome. Similarly, non-steroidal anti-inflammatory medication is not likely to help pain that results from mechanical internal disc derangement, adaptively shortened soft tissues or mechanical instability.

To illustrate this more clearly an analogy is useful. Suppose we were to apply the same research methodology to, say, ‘non-specific knee pain’ that we will call ‘knee syndrome’. We want to compare the effect of resisted knee extension exercises with ultrasound therapy on pain and disability. In this hypothetical study we include all patients with knee pain but exclude fractures and obvious pathologic entities such as medial meniscus tears and ruptured cruciate or medial ligaments. Patients fulfilling the inclusion criteria are randomly assigned to two treatment groups, one group receiving ultrasound to the painful part and the other a progressive resisted extension exercise protocol. The patients receive a specified number of treatments over a specified time period. Pain and disability instruments are used prior to treatment, and one month, six months and 12 months after the start of treatment. Assessors blinded to which treatment the patient has received, are used to evaluate pain and disability. Results are analysed by an independent and blinded statistician for differences in outcome. We can speculate that there would be little difference between the two treatment groups and the conclusion would be reached that neither treatment is superior. If a third (control) group were managed with analgesics or an educational booklet, the two active treatments would most likely fail to achieve a superior outcome.

A cCriticism of this study design seems obvious. While the research method is sound, the general thrust of the research is likely to produce equivocal results. Treatments that may be very successful in managing a specific pathology, may be seen as of little value when applied to a variety of different pathologies. Most clinicians actively treating patients with lower limb problems on a daily basis, recognise that ‘knee syndrome’ is not a diagnosis but merely a description of the patient’s complaint. Retropatellar chondomalacia, minor internal derangement, medial ligament, lateral ligament, coronary ligament, anterior and posterior cruciate ligament strains, fat pad irritation, prepatellar or pes anserinus bursitis, patellar tendinitis, among other problems will all fall into the group being studied. It is easy to see how a difference in the proportion of a certain pathology in the study population could affect the outcome. If a high proportion of retropatellar disorders were present in the study group, resisted knee extension exercises may prove superior to the control or ultrasound group. If, on the other hand, simple ligament strains predominate, it is possible that the ultrasound group would prove to be superior. If minor internal derangements (as occur in middle aged people) were common in the study population, resisted extension exercises may worsen the pain whereas ultrasound would have little or no effect.

It is suggested that outcome studies should be carried out comparing the effects of different treatments on homogeneous groups with single pathologies. In such studies, randomisation would occur after identification of a particular condition in order to be able to find out whether there is a superior treatment for that condition. To continue our hypothetical analogy, patients with, for example, only retropatellar pathologies should be randomised into different treatment groups. If a difference in outcome is observed, one treatment is shown to be superior for retropatellar pathologies. The result cannot be extrapolated to other pathologies.

Now let us return to the question of non-specific low back pain and to the study by Cherkin, D.C., et al. (1998) mentioned earlier. The study population was a subgroup of the non-specific back pain population. Included were patients without sciatica (QTF classes 1 & 2), and with symptoms of more than one week’s duration, most of whom had had pain for less than six weeks (QTF subacute stage). The study demonstrated that chiropractic and modified McKenzie therapy resulted in only marginally better outcomes than the minimal intervention of an educational booklet known to be ineffective. One possible explanation is that the QTF classification system is impractical for the purposes of identifying the best treatment for specific pathologies.

In view of the above, it is essential to continue the search for a method of classification that produces groups of patients that can be identified as having the same or similar pathologies and therefore may respond to specific treatments. This will be facilitated by the use of clear definitions and minimal criteria for each identifiable pathology.

What then is a method of classification that may help in identifying those patients that can respond to specific treatments? It is proposed that a mixture of patho-anatomic diagnoses and McKenzie syndromes has potential. Table 3 sets out a classification system that complies with the method of Buchbinder, R. et al. (1994). The conceptual domain is ‘Low back and referred pain’ and there are 12 categories or subgroups that can be identified within this domain. (Insert table 3 somewhere here.)

The existence of symptomatic disc, ZJ and SIJ pathologies (the first three categories) may be considered with respect to the research discussed earlier. They account for about 70% of low back and referred pain cases (Bogduk, N. 1995). The diagnostic method for identifying these subgroups is not set in stone. For example, diagnostic injections as described above are able to differentiate between symptomatic disc, ZJ and SIJ pathologies. However, there is preliminary evidence that one type of physical examination may be able to achieve similar results, at least with regard to discogenic pain (Donelson, R. et al. 1997) and symptomatic SIJ pathologies (Young, S., Laslett, M., Aprill, C., Donelson, R., & Kelly, C. 1998). The researchers in the latter study are currently investigating the ability of a specific physical examination and clinical reasoning process to differentiate between symptomatic ZJ’s, SIJ’s and intervertebral discs. If a good level of reliability can be achieved, diagnostic injections are not needed to categorise these patients and the physical examination can be used both clinically and for further research.

In this paper it is not possible to give details of the physical examination method used to differentiate between disc, SIJ and ZJ pain. The paper by Donelson, R. et al. (1997) gives an excellent summary of the McKenzie method of examination that was used in their study. The study comparing diagnostic judgements from the physical examination and injection into the SIJ (Young, S. et al. 1998) demonstrates that a good level of diagnostic power was achieved. The examination method used was the McKenzie assessment augmented by provocation stress tests of the SIJ (Laslett, M. & Williams, M. 1994). A specific reasoning process using the McKenzie examination to exclude symptomatic disc pathology was applied to minimise false positives enabling an improved ability to differentiate between SIJ and non-SIJ cases. Study of these papers will give the reader sufficient information to understand the method.

The posture syndrome and dysfunction syndrome as defined by the McKenzie approach are convenient categories for patients who satisfy specific clinical behaviours but in whom no anatomical site of pathology is identifiable by current techniques. The frequency of these syndromes in any patient population is unknown. There are, however, problems with clinicians’ reliability in identifying these cases (Riddle, D.L. & Rothstein J.M., 1993). Further work must be undertaken to refine and then reassess the skill of clinicians in this form of diagnosis.

Satisfying relevant definitions and criteria documented by the McKenzie approach may identify the dysfunction and posture syndromes. To place a patient within either of these two categories, the clinical findings should not satisfy the criteria for any other category. The following scenario that leads to the diagnosis of posture syndrome may illustrate the process. The patient has low back pain. The history and physical examination are completed. When analysing the information, the criteria for discogenic pain, symptomatic ZJ, SIJ and hip joint are not satisfied (excluding categories 1, 2, 3 and hip joint). The patient only has local back pain without radiation into the buttocks or lower limbs (excluding categories 4, 5 & 6.) Radiographs reveal no spondylolysis or spondylolisthesis and there are no signs or symptoms typical of mechanical instability (excluding category 7). The patient answers questions clearly and does not give the impression of seeking secondary gain. The Waddell tests for non-organic pain are negative. Illness behaviour (category 10) seems unlikely. The patient reports good health and there are no symptoms suggestive of visceral or other organic disease (excluding category 11). The pain develops only after sitting or bending for prolonged periods, but rapidly diminishes and stops once the patient gets out of the painful posture. There is no loss of motion and all test movements are pain free (excluding category 9). This clinical picture satisfies the criteria for posture syndrome.

The clinical reasoning process that leads to the categories within this proposed classification system is presented in an algorithm (Figure 1). (Insert figure 1 (two pages) at the nearest location where the two consecutive pages can be placed together as in an open book, making sure the book can be held in one position to view both pages.) Note that the decision diamonds require the satisfaction of specific criteria at critical pivot points in the reasoning process. The structure and method are further illustrated in the Appendix, which provides definitions and minimal criteria for the proposed categories and some associated concepts.

The development of this classification system is still in process. Validation of the system is tenuous at best. The justification for selecting the categories as outlined is based upon a mixture of clinical experience, the results of specific research projects identifying pain producing structures, and two studies on the diagnostic power of the physical examination (Donelson, R. et al. 1997,; Young, S. et al. 1998). Clearly this is inadequate. A great deal of further research needs to be done to test for construct validity and other aspects. Ongoing research will assess the diagnostic power of the physical examination compared to accepted criterion standards. Studies into diagnostic power would appear to be a first priority. Sensitivity, specificity and other aspects of diagnostic power are measured in a variety of ways and this will be discussed in a companion paper (Laslett, M. in press). Randomised controlled trials of different treatments on cases identified as belonging to a specific subclassification would need to follow.

It is proposed that painful lumbar spine pathologies be subcategorised into 12 categories for use in clinical management and research (Table 3). Diagnostic injections can differentiate between symptomatic disc, SIJ and lumbar ZJ but they are invasive, expensive and not readily available to the great majority of patients. There is preliminary evidence that one type of physical examination may reliably predict the results of diagnostic injections. It is inexpensive to train physiotherapists to carry out this type of evaluation. These physiotherapists would have an important role in categorising patients prior to the performance of studies comparing different treatment methods.

Outcome research on undifferentiated LBP has been shown to have limited utility in identifying which treatments are best for which cases. The proposed classification system offers the potential to identify the tissue source of pain, and could form the foundation of future research into the efficacy of different treatments.

Bogduk, N. (1995). The anatomical basis for spinal pain syndromes. J. of Manip. & Physiol. Therapeutics, 18, 9, 603-605

Buchbinder, R., Goel, V., Bombadier, C. (1994). Working paper #14: A methodological framework for the critical appraisal of classification systems. Institute for Work and Health, Toronto, Ontario, Canada

Cherkin, D.C., Deyo, R.A., Street, J.H., Hunt, M., Barlow, W. (1998). Pitfalls of patient education: limited success of a program for back pain in primary care. Spine, 21, 345-355

Cherkin, D.C., Deyo, R.A., Battie, M., Street, J., Barlow, W. (1998). A comparison of physical therapy, chiropractic manipulation, and provision of an educational booklet for the treatment of patients with low back pain. The New England Journal of Medicine, 339, 15, 1021-1029

Cyriax J. (1983). Textbook of orthopaedic medicine, Volume 1, Diagnosis of soft tissue lesions (8^th ed.). Chapter 23. London, England: Balliere Tindall

Deyo, R.A., Battie, M., Beurskens, A.J.H.M., Bombardier, C., Croft, P., Koes, B., Malmivaara, A., Roland, M., Von Korff, M., Waddell, G.(1998). Outcome measures for low back pain research. A proposal for standardized use. Spine, 23, 2003-2013

Donelson, R., Aprill, C., Medcalf, R., Grant, W. (1997). A prospective study of centralization of lumbar and referred pain. A predictor of symptomatic discs and anular competence. Spine, 22, 10, 1115-1122

Dong, G.X., Porter R.W. (1989). Walking and cycling tests in neurogenic and intermittent claudication. Spine, 14, 965-969

Dreyfuss, P., Michaelsen, M., Pauza, K., McLarty, J., Bogduk, N. (1996). The value of medical history and physical examination in diagnosing sacroiliac joint pain. Spine, 21, 2222, 2594-2602

Faas, A., van Eijck, J.Th.M., Chavannes, A.W., Gubbels, J.W. (1995). A randomized trial of exercise therapy in patients with acute low back pain. Efficacy on sickness absence. Spine, 20, 8, 941-111111947

Faas, A. (1996). Exercises: Which ones are worth trying, for which patients, and when? Spine, 21, 24, 2874-2879

Fairbank, J.T.C., Couper, J., Davies, J.B., O’Brien, J.P. (1980). The Oswestry Low Back Pain Disability Questionnaire. Physiotherapy, 66, 8, 271-274

Fritz, J.M., Erhard, R.E., Delitto, A., Welch, W.C., Nowakowski, P. (1997). Preliminary results of the use of a two-stage treadmill test as a clinical diagnostic tool in the differential diagnosis of lumbar spinal stenosis. J Spinal Dis, 10, 410-416

Fritz, J.M., Delitto, A., Welch, W.C., Erhard, R.E. (1998). Lumbar spinal stenosis: A review of current concepts in evaluation, management and outcome measurements. Arch Phys Med Rehabil, 79, 700-708

Jackson, R.P. (1992). The facet syndrome. Myth or reality. Clin. Orthop., 279, 110-121

Kankaanpää, M., Taimela, S., Airaksinen, O., Hänninen, O. (1999) The efficacy of active rehabilitation in chronic low back pain. Effect on pain intensity, self-experienced disability, and lumbar fatigability. Spine, 24, 10, 1034-1042

Katz, J.N., Dalgas, M., Stucki, G., Lipson, S.G. (1995). Degenerative lumbar spinal stenosis. Diagnostic value of the history and physical examination. Athritis & Rheumatism, 38, 1236-1241

Koes, B.W., Bouter, L.M., Beckerman, H., van der Heijden G.J.M.G., Knipschild, P.G. (1991). Physiotherapy exercises and back pain: a blinded review. BMJ, 302, 1572-1576

Laslett, M., Williams, M. (1994). The reliability of selected pain provocation tests for sacroiliac joint pathology. Spine, 19, 11, 1243-1249

Lawlis, G.F., Cuencas, R., Selby, D., McCoy, C.E. (1989). The development of the Dallas Pain Questionnaire. An assessment of the impact of spinal pain on behavior. Spine, 14, 5, 511-516

Leclaire, R., Blier, F., Fortin, L., Proulx, R. (1997). A cross-sectional study comparing the Oswestry and Roland-Morris functional disability scales in two populations of patients with low back pain of different levels of severity. Spine, 22, 1, 68-71

Leggett, S., Mooney, V., Matheson, L.N., Nelson, B., Dreisinger, T., Van Zytveld, J., Vie, L. (1999). Restorative exercise for clinical low back pain. A prospective two-center study with 1-year follow-up. Spine, 24, 9, 889-898

Lønn, J.H., Glomsrød, B., Soukup, M.G., Bø, K., Larsen, S. (1999) Active back school: Prophylactic management for low back pain. A randomized, controlled, 1-year follow-up study. Spine, 24, 9, 865-871

McKenzie, R.A. (1981). The Lumbar Spine. Mechanical Diagnosis and Therapy. Waikanae, New Zealand: Spinal Publications Ltd

McKenzie, R.A. (1990). The cervical and thoracic spine. Mechanical Diagnosis and Therapy. Waikanae, New Zealand: Spinal Publications Ltd

Maigne, J-Y., Aivaliklis, A., Pfefer, F. (1996). Results of sacroiliac joint double block and value of sacroiliac pain provocation tests in 54 patients with low back pain. Spine, 21, 16, 1889-1892

Main, C.J., Waddell, G. (1998). Behavioral responses to examination. A reappraisal of the interpretation of "nonorganic signs". Spine, 23, 21, 2367-2371

National Advisory Committee on Health and Disability & Accident Rehabilitation and Compensation Insurance Corporation (1997). New Zealand acute low back pain guide. Ministry of Health & Accident Rehabilitation and Compensation Insurance Corporation: Wellington, New Zealand

Ombregt, L., Bisschop, P., ter Veer, H.J., Van de Velde, T. (1995). A system of orthopaedic medicine. Section 12. London, England: WB Saunders Company Ltd

Panjabi, M.M. (1992a). The stabilising system of the spine. Part I. Function, dysfunction, adaptation, and enhancement. J Spinal Disorders 5, 4, 383-389

Panjabi, M.M. (1992b). The stabilising system of the spine. Part II. Neutral zone and instability hypothesis. J Spinal Disorders 5, 4, 390-397

Revel, M., Poiraudeau, S., Auleley, G.R., Payan, C., Denke, A., Nguyen, M., Chevrot, A., Fermanian, J. (1998). Capacity of the clinical picture to characterize low back pain relieved by facet joint anesthesia. Proposed criteria to identify patients with painful facet joints. Spine, 23, 18, 1972-1977

Richardson, C., Jull, G., Hodges, P., Hides, J. (1999). Therapeutic exercise for spinal segmental stabilization in low back pain. Scientific basis and clinical approach. London, England: Churchill Livingstone

Riddle, D.L., Rothstein J.M. (1993). Intertester reliability of McKenzie's classifications of the syndrome types present in patients with low back pain. Spine, 18, 10, 1333-1344

Riddle, D.L. (1998). Classification and low back pain: A review of the literature and critical analysis of selected systems. Physical Therapy, 78, 7, 708-737

Roland, M., Morris, R. (1983). A study of the natural history of back pain. Part I: Development of a reliable and sensitive measure of disability in low back pain. Spine, 8, 2, 141-144

Schonstrom, N., Boleander, N.F., Spengler, D.M. (1985). The pathomorphology of spinal stenosis as seen on CT scans of the lumbar spine. Spine, 10, 806-811

Schwarzer, A.C., Aprill, C.N., Derby, R., Fortin, J., Kine, G., Bogduk, N. (1994a). Clinical features of patients with pain stemming from the lumbar zygapophysial joints. Is the lumbar facet syndrome a clinical entity? Spine, 19, 10, 1132-1137

Schwarzer, A.C., Derby, R., Aprill, C.N., Fortin, J., Kine, G., Bogduk, N. (1994b). Pain from the lumbar zygapophysial joints: A test of two models. J Spinal Dis, 7, 4, 331-336

Schwarzer, A.C., Aprill, C.N., Bogduk, N. (1995). The sacroiliac joint in chronic low back pain. Spine, 20, 1, 31-37

Schwarzer, A.C., Aprill, C.N., Derby, R., Fortin, J., Kine, G., Bogduk, N. (1995). The prevalence and clinical features of internal disc disruption in patients with chronic low back pain. Spine, 20, 17, 1878-1883

Shekelle, P.G. (1994). Spinal manipulation. Spine, 19, 7, 858-861

Skargren, E.I., Carlsson, P.G., Öberg, B.E. (1998). One-Year follow-up comparison of the cost and effectiveness of chiropractic and physiotherapy as primary management for back pain. Subgroup analysis, recurrence, and additional health care utilization. Spine, 23, 17, 1875

Spitzer, W.O. (1987). Scientific approach to the assessment and management of activity-related spinal disorders. A monograph for clinicians. Report of the Quebec Task Force on Spinal Disorders. Spine, 12, 7S

Taub, N.S., Worsowicz, G.M., Gnatz, S.M., Cifu, D.X. (1998). Pain rehabilitation. 1. Definitions and diagnosis of pain. Arch Phys Med Rehabil, 79, S 49-S 53

Waddell, G., McCulloch, J.A., Kummel, E., Venner, R.M., (1980). Non-organic physical signs in low back pain. Spine, 5, 117-125

Young, S., Laslett, M., Aprill, C., Donelson, R., Kelly, C. (1998). The Sacroiliac Joint: A study comparing physical examination and contrast enhanced pain provocation/anesthetic block arthrography. Proceedings North American McKenzie Institute Conference ‘Comprehensive musculo-skeletal patient management: McKenzie and beyond. (p. 28). New Orleans, Louisiana, U.S.A.

"A painful displacement of the contents of an intervertebral disc that is reversible by specific mechanical loading strategies so that pain and movement obstruction are abolished."

• at least one movement is painfully obstructed
• there are mechanical loading strategies that decrease, centralise and abolish the symptoms and movement obstruction within a time frame of days or weeks.

1. To determine the reducibility of the derangement, the dynamic mechanical evaluation must be carried out with movements taken to end range. Movements must be repeated in sufficient numbers and over sufficient time, in some cases over a number of days.
2. The time frame is intentionally left flexible for several reasons including the following:

• Episodes of longer duration require a proportionately longer time for reduction of the derangement.
• The presence of a relevant ipsilateral shift will considerably lengthen the time required for reduction of the derangement.
• Re-derangement will lengthen the time for reduction of the derangement.
• Psychosocial factors, illness behaviour and secondary gain considerations will affect the prognosis and may prevent recovery entirely.

"Centralisation is a pattern of symptomatic response to specific mechanical loading strategies characterised by a retreat of referred symptoms towards the midline of the spine."

Diagrammatically, components of the spine and limbs are presented in Figure 2. (Insert figure 2 somewhere here.)

• symptoms in the most distal component of the referral pattern are abolished by specific loading strategies
• the abolition of symptoms in the most distal component must be progressive and retained over time
• the abolition of symptoms in the most distal component must be continuous so that ultimately symptoms are felt only in the midline of the spine or an area just adjacent to the spine
• completion of the process of centralisation must occur within a week or two, providing re-injury has not occurred.

"Directional preference is the direction of mechanical loading that leads to a lasting improvement or abolition of the symptoms, in contrast to one or more other directions that lead to a lasting worsening of the symptoms."

• mechanical loading strategies in one direction decrease, centralise or abolish the symptoms
• mechanical loading strategies in one or more other directions produce, increase or peripheralise the symptoms.

Definition:

"Peripheralisation is a pattern of symptomatic response to specific mechanical loading strategies characterised by an increasing reference of symptoms away from the midline of the spine."

• symptoms are produced in a more distal component of the pain pattern in response to a specific loading strategy
• the production of symptoms in a more distal component of the pain pattern is progressive and retained over time.

1. The natural history of prolapsed intervertebral disc lesions follows a course of progressively increasing referral of symptoms into the limb.
2. Peripheralisation is the reverse of centralisation, i.e. it is the observation that symptoms of spinal origin progress into the limb as the pathology worsens.
3. Repeated movements and sustained positions used in examination and therapy that cause peripheralisation are to be avoided as they indicate a worsening causal pathology.

"A painful displacement of the contents of an intervertebral disc that is not reversible by mechanical loading strategies."

• there are no mechanical loading strategies that substantially decrease, centralise and abolish the symptoms or movement obstruction within a time frame of days or weeks
• flexion loading worsens the symptoms.

• predominant pain is midline or bilateral above S1
• predominant pain is unilateral and above S1 but Revel’s zygapophysial joint criteria are not satisfied.
• symptoms change sides under the influence of unilateral procedures.

"A painful condition caused by a tear in the posterior or posterolateral annulus of an intervertebral disc."

• history of recent, sudden strain in flexion
• dominant back pain
• there are no mechanical loading strategies that decrease, centralise and abolish the symptoms.

1. This disorder is often confused with a mechanical derangement of the disc. The inability to centralise or rapidly reduce the symptoms is the key factor indicating a posterior annular tear.
2. An obstruction to extension and/or lateral flexion may be apparent and is the most common reason for confusion with mechanical derangement. Accumulation of fluid (blood or oedema) at the site of the tear causes the space occupying mechanical behaviour but since this cannot be moved with repeated movements or positioning, rapid restoration of movement range and centralisation of symptoms is not possible.

Definition:

"A painful condition in which the principal source of nociceptor receptor activity is a zygapophysial joint."

Pain well-relieved by lying down and the presence of at least four of the following criteria (Revel, M. et al. 1998):

• age greater than 65 years
• pain not increased by coughing
• no pain with flexion in standing
• pain not increased by rising from flexion
• pain not increased by extension / rotation
• pain not increased by extension in standing.

six of the seven statements are true

1. This study contradicts the findings of other studies (Jackson, R. 1992) and has methodological weaknesses. Use of the criteria outlined by Revel, M. et al. (1998) must be accompanied with caution, even scepticism. The criteria are included here, as they appear to be the only available evidence suggesting that a symptomatic zygapophysial joint can be identified without the use of diagnostic injections.

"A painful condition in which the principal source of nociceptor receptor activity is a sacroiliac joint."

• disc criteria are not satisfied
• ZJ criteria are not satisfied
• three or more SIJ pain provocation tests are positive (Laslett, M. & Williams, M. 1994).

"A painful condition in which the principal source of nociceptor receptor activity is an intervertebral disc but no evidence for mechanical derangement exists."

• one or more ‘other disc characteristics’ are present
• SIJ criteria are not satisfied
• ZJ criteria are not satisfied
• criteria for reducible or irreducible mechanical disc lesion are not satisfied.

"A flexion dysfunction resulting from scarring involving a nerve root, causing limitation of nerve root mobility and dominant leg symptoms in a sciatic distribution."

• dominant symptoms below the gluteal fold.
• history of lumbar spine surgery or acute sciatica at least two months ago, which has partially resolved.
• flexion in standing is restricted and produces end range symptoms referred into the limb
• repeated flexion in standing does not leave the symptoms worse as a result
• extension in standing or lying and flexion in lying do not produce the referred symptoms.

"Dominant lower limb symptoms caused by irreducible compression and movement restriction of a lumbar nerve root."

• history of acute disc prolapse causing constant nerve root symptoms
• flexion in standing is limited and produces or increases lower limb symptoms at end range
• repeated flexion in standing does not decrease the lower limb symptoms but can result in a temporary increase in movement range
• no movement, position or combination of movements and positions can centralise or decrease the lower limb symptoms.

"A painful disorder caused by a significant decrease in the capacity of the stabilizing system of the spine to maintain the intervertebral neutral zones within physiological limits." (Panjabi, M.M. 1992b)

• Ddominant back pain
• Rrecurring episodes of pain or persistent pain with recurrent exacerbations
• Nno obstruction of extension and flexion by loading in the opposite direction
• iInability to isolate transversus abdominis contraction
• eEvidence of increased pain or lack of control in the neutral zone (Panjabi, M.M. 1992a & 1992b).

"A painful disorder resulting from mechanical deformation by prolonged static end range loading of innervated normal soft tissues."

• full range of motion in all directions
• no pain with any movement
• repeated dynamic end range loading does not produce symptoms
• sustained end range loading in at least one direction produces the familiar symptoms.

"A painful disorder resulting from mechanical deformation by end range loading of innervated shortened soft tissues."

• at least one movement is restricted in range
• the restricted movement produces familiar symptoms at end range
• dynamic end range loading in the painfully restricted direction of motion does not progressively increase, peripheralise or worsen the symptoms
• dynamic end range loading in the painfully restricted direction does not obstruct the movement range in any direction.

"Intermittent neurogenic claudication of the lower limb secondary to a significant narrowing of the lumbar spinal canal or a lumbar nerve root canal."

• dominant symptoms below the gluteal fold
• history of intermittent neurogenic claudication
• no evidence of directional preference and centralisation is not possible
• symptoms improved when seated (Katz, J.N., Dalgas, M., Stucki, G., & Lipson, S.G. 1995) or improved walking tolerance with the spine in flexion (Dong, G.X. & Porter, R.W. 1989)
• best posture with regard to symptoms is sitting or worst postures with regard to symptoms is standing or walking (Fritz, J.M., Erhard, R.E., Delitto, A., Welch, W.C., & Nowakowski, P. 1997).

If the cross-sectional area is between 76 and 100 mm² at the narrowest point, the degree of stenosis is regarded as moderate.

1. Cross-sectional areas less than 76 mm² are regarded as severe stenosis (Schonstrom, N., Boleander, & N.F., Spengler, D.M. (1985).

1. The classification defined here refers only to cases with appropriate symptoms and does not refer to asymptomatic stenosis as revealed by CT or MRI scans or other imaging studies.

"A painful lesion located within the hip or buttock structures producing dominant buttock or leg symptoms."

A number of different disorders are included in this category and specific minimal criteria for each condition is beyond the scope of this paper. However there are a number of conditions that may confuse the clinician since the symptoms may mimic referred pain from the lumbar spine or pelvis. The following list contains the most common hip and buttock lesions that may cause confusion:

• osteoarthrosis of the hip

gluteal bursitis

• derangement of a loose body in the hip
• psoas bursitis
• trochanteric bursitis.

The reader is referred to appropriate textbooks for the diagnosis of these lesions (Cyriax J. 1983,; Ombregt, L., Bisschop, P., ter Veer, H.J., & Van de Velde, T. 1995).

"Any conscious or subconscious exaggeration or modification of symptoms or disability disproportionate to the degree of injury or pathology."

The minimal criteria for this classification are still in development. The use of pain and disability questionnaires, visual analogue scales, pain drawings, physical tests for non-organic pain and other instruments to measure pain and disability have widespread acceptance (Deyo, R.A. et al. 1998). Also of value are self-assessment tools such as:

• the Oswestry low back pain disability questionnaire (Fairbank, J.T.C., Couper, J., Davies, & J.B., O’Brien, J.P. 1980)
• the Roland-Morris disability questionnaire (Roland, M. & Morris, R. 1983,; Leclaire, R., Blier, F., Fortin, L., & Proulx, R. 1997)
• the Dallas pain questionnaire (Lawlis, G.F., Cuencas, R., Selby, D., & McCoy, C.E. (1989)
• the tests for non-organic pain described by Waddell (Waddell, G., McCulloch, J.A., Kummel, E., & Venner, R.M. 1980,; Main, C.J., & Waddell, G. 1998).

Mark Laslett

Bay-Roskill Physiotherapy Clinic

211 White Swan Road

Mount Roskill

Auckland 4

New Zealand

Note: Cases in QTF classes 1 to 4 are annotated as acute (less than 7 days), subacute (7 days to 7 weeks), chronic (more than 7 weeks), working, not working.

 

Table 2. McKenzie classification systemm

• at least one movement is painfully obstructed
• there are mechanical loading strategies that decrease, centralise and abolish the symptoms and movement obstruction within a time frame of days or weeks.

1. To determine the reducibility of the derangement, the dynamic mechanical evaluation must be carried out with movements taken to end range. Movements must be repeated in sufficient numbers and over sufficient time, in some cases over a number of days.
2. The time frame is intentionally left flexible for several reasons including the following:

• Episodes of longer duration require a proportionately longer time for reduction of the derangement.
• The presence of a relevant ipsilateral shift will considerably lengthen the time required for reduction of the derangement.
• Re-derangement will lengthen the time for reduction of the derangement.
• Psychosocial factors, illness behaviour and secondary gain considerations will affect the prognosis and may prevent recovery entirely.

Diagrammatically, components of the spine and limbs are presented in Figure 2. (Insert figure 2 somewhere here.)

• symptoms in the most distal component of the referral pattern are abolished by specific loading strategies
• the abolition of symptoms in the most distal component must be progressive and retained over time
• the abolition of symptoms in the most distal component must be continuous so that ultimately symptoms are felt only in the midline of the spine or an area just adjacent to the spine
• completion of the process of centralisation must occur within a week or two, providing re-injury has not occurred.

• mechanical loading strategies in one direction decrease, centralise or abolish the symptoms
• mechanical loading strategies in one or more other directions produce, increase or peripheralise the symptoms.

Definition:

"Peripheralisation is a pattern of symptomatic response to specific mechanical loading strategies characterised by an increasing reference of symptoms away from the midline of the spine."

• symptoms are produced in a more distal component of the pain pattern in response to a specific loading strategy
• the production of symptoms in a more distal component of the pain pattern is progressive and retained over time.

1. The natural history of prolapsed intervertebral disc lesions follows a course of progressively increasing referral of symptoms into the limb.
2. Peripheralisation is the reverse of centralisation, i.e. it is the observation that symptoms of spinal origin progress into the limb as the pathology worsens.
3. Repeated movements and sustained positions used in examination and therapy that cause peripheralisation are to be avoided as they indicate a worsening causal pathology.

• there are no mechanical loading strategies that substantially decrease, centralise and abolish the symptoms or movement obstruction within a time frame of days or weeks
• flexion loading worsens the symptoms.

Definition:

"A painful condition in which the principal source of nociceptor receptor activity is a zygapophysial joint."

Pain well-relieved by lying down and the presence of at least four of the following criteria (Revel, M. et al. 1998):

• age greater than 65 years
• pain not increased by coughing
• no pain with flexion in standing
• pain not increased by rising from flexion
• pain not increased by extension / rotation
• pain not increased by extension in standing.

six of the seven statements are true

• disc criteria are not satisfied
• ZJ criteria are not satisfied
• three or more SIJ pain provocation tests are positive (Laslett, M. & Williams, M. 1994).

• one or more ‘other disc characteristics’ are present
• SIJ criteria are not satisfied
• ZJ criteria are not satisfied
• criteria for reducible or irreducible mechanical disc lesion are not satisfied.

"A flexion dysfunction resulting from scarring involving a nerve root, causing limitation of nerve root mobility and dominant leg symptoms in a sciatic distribution."

• dominant symptoms below the gluteal fold.
• history of lumbar spine surgery or acute sciatica at least two months ago, which has partially resolved.
• flexion in standing is restricted and produces end range symptoms referred into the limb
• repeated flexion in standing does not leave the symptoms worse as a result
• extension in standing or lying and flexion in lying do not produce the referred symptoms.

• history of acute disc prolapse causing constant nerve root symptoms
• flexion in standing is limited and produces or increases lower limb symptoms at end range
• repeated flexion in standing does not decrease the lower limb symptoms but can result in a temporary increase in movement range
• no movement, position or combination of movements and positions can centralise or decrease the lower limb symptoms.

• dominant back pain
• recurring episodes of pain or persistent pain with recurrent exacerbations
• no obstruction of extension and flexion by loading in the opposite direction
• inability to isolate transversus abdominis contraction
• evidence of increased pain or lack of control in the neutral zone (Panjabi, M.M. 1992a & 1992b).

• full range of motion in all directions
• no pain with any movement
• repeated dynamic end range loading does not produce symptoms
• sustained end range loading in at least one direction produces the familiar symptoms.

• at least one movement is restricted in range
• the restricted movement produces familiar symptoms at end range
• dynamic end range loading in the painfully restricted direction of motion does not progressively increase, peripheralise or worsen the symptoms
• dynamic end range loading in the painfully restricted direction does not obstruct the movement range in any direction.

• dominant symptoms below the gluteal fold
• history of intermittent neurogenic claudication
• no evidence of directional preference and centralisation is not possible
• symptoms improved when seated (Katz, J.N., Dalgas, M., Stucki, G., Lipson, S.G. 1995) or improved walking tolerance with the spine in flexion (Dong, G.X. & Porter R.W. 1989)
• best posture with regard to symptoms is sitting or worst postures with regard to symptoms is standing or walking (Fritz, J.M., Erhard, R.E., Delitto, A., Welch, W.C., Nowakowski, P. 1997).

If the cross-sectional area is between 76 and 100 mm² at the narrowest point, the degree of stenosis is regarded as moderate.

1. Cross-sectional areas less than 76 mm² are regarded as severe stenosis (Schonstrom, N., Boleander, N.F., Spengler, D.M. (1985).

1. The classification defined here refers only to cases with appropriate symptoms and does not refer to asymptomatic stenosis as revealed by CT or MRI scans or other imaging studies.

A number of different disorders are included in this category and specific minimal criteria for each condition is beyond the scope of this paper. However there are a number of conditions that may confuse the clinician since the symptoms may mimic referred pain from the lumbar spine or pelvis. The following list contains the most common hip and buttock lesions that may cause confusion:

• osteoarthrosis of the hip

gluteal bursitis

• derangement of a loose body in the hip
• psoas bursitis
• trochanteric bursitis.

The reader is referred to appropriate textbooks for the diagnosis of these lesions (Cyriax J. 1983, Ombregt, L., Bisschop, P., ter Veer, H.J., Van de Velde, T. 1995).

The minimal criteria for this classification are still in development. The use of pain and disability questionnaires, visual analogue scales, pain drawings, physical tests for non-organic pain and other instruments to measure pain and disability have widespread acceptance (Deyo, R.A. et al. 1998). Also of value are self-assessment tools such as:

• the Oswestry low back pain disability questionnaire (Fairbank, J.T.C., Couper, J., Davies, J.B., O’Brien, J.P. 1980)
• the Roland-Morris disability questionnaire (Roland, M. & Morris, R. 1983, Leclaire, R., Blier, F., Fortin, L., Proulx, R. 1997)
• the Dallas pain questionnaire (Lawlis, G.F., Cuencas, R., Selby, D., McCoy, C.E. (1989)