Literature Relevant to the McKenzie Approach
By Stephen May

LITERATURE RELEVANT TO THE McKENZIE APPROACH

The following articles are grouped together according to the type of study as follows:

Systematic Reviews - These reviews use clearly defined strategies for searching the literature, explicit criteria for appraising the quality of papers reviewed, and a validated method of analysing those papers. They only ever review randomised controlled trials (RCT), and are considered the strongest form of evidence in the hierarchy of evidence to judge health care interventions. In this section only systematic reviews of interventions, other systematic reviews are included in relevant sections.

Reviews - These papers review aspects of treatment. As they may use incomplete databases, subjective abstraction of data, and undefined methods of analysis they are considered to be unscientific.

Trials - These are primary research papers following a group of patients through a particular intervention(s). The patients may be randomised to different treatment groups, there may be a control group, or they may simply be a set of patients followed through a particular practice. The strongest form of primary research evidence is a RCT. Not all these papers have been published in peer reviewed journals. They concern studies that have claimed to use the McKenzie approach or else flexion or extension exercises.

Centralisation - These are primary research papers that illustrate the prognostic value of centralisation - most, though not all, studies relate to the lumbar spine.

Surveys of McKenzie regimes - These are primary research papers that retrospectively survey series of patients who have been treated with the McKenzie approach and report on different aspects of prognosis and outcome. Also included here are general surveys of physiotherapy practice, which include therapists' use of the McKenzie approach.
Studies into assessment procedures, tests & techniques - These are primary research studies into the reliability and validity of McKenzie assessment, or aspects of it. Also included here are articles about classification of back pain, and descriptions of some techniques.

Anatomical & physiological studies - In vitro and in vivo studies looking at the effects of different mechanical loading. For instance reviews of different postures, the effects of flexion/extension on intradiscal material, pain provocation studies etc.

Overviews of McKenzie approach - Original material written by McKenzie and other authors that describe the method of assessment and treatment for both lumbar and cervical spines.

Discussion articles - Papers in which the authors present a didactic analysis of some aspect of spinal care relevant to the McKenzie approach.

Cervical Spine - Papers on the cervical spine are far fewer in number than on the lumbar spine. Overviews of the McKenzie approach are included in the above section. Separate sections are as follows:

• Systematic reviews.
• Trials.
• Anatomical, physiological, and pain studies.
• Whiplash.
• Correspondence - Letters concerning some of the previous articles (lumbar and cervical).

* Denotes an article of particular importance for mechanical diagnosis and therapy.

LUMBAR SPINE
SYSTEMATIC REVIEWS
Belanger A Y, Depres M C, Goulet H, Trottier F; The McKenzie Approach: How Many Clinical Trials support Its Effectiveness? Proceedings of the World Confederation for Physical Therapy 11th International Congress, 28 July - 2nd August 1991, London, UK.
A review and analyses of the scientific literature that supports the effectiveness of the McKenzie approach. It concludes that despite worldwide popularity, scientific validation of the method is still not available

Danish Institute for Health Technology Assessment: Low-back pain. Frequency, management and prevention from an HTA perspective. Danish Health Technology Assessment 1-106, 1999.
This wide ranging review and guideline includes a summary of the McKenzie approach, both as a treatment and as a diagnostic method. They concluded there was limited evidence to support its use as a treatment for both acute and chronic back pain, and moderate evidence indicating its value as a diagnostic tool and prognostic indicator.

Faas A, Exercises. Which ones are worth trying, for which patients, and when? Spine, 21, 24, 2874-2879, 1996
A review of 11 randomised exercise trials concerning exercise therapy. Two trials of McKenzie type exercises reported positive results but had low method scores.

Koes B W, Bouter L M, Beckerman H, van der Heijden G J M G, Knipschild P G: Physiotherapy exercises and back pain: a blinded review. BMJ 302;1572-1576, June 1991.
Koes concludes that the quality of research on the effect of exercises in the treatment of LBP is disappointingly low and, therefore, no conclusion can be drawn on whether exercise is better than other treatments or whether a specific type of exercise is more effective.

Philadelphia panel evidence-based clinical practice guidelines on selected rehabilitation interventions for low back pain. Physical Therapy 81; 1641-1674, 2001.
These guidelines have been developed using a structured and rigorous methodology. For sub-acute and chronic back pain they recommend that there is good evidence to include certain specific exercises, including the McKenzie method.

Reddeck T: The Efficacy of the McKenzie Regimen - A Meta-analysis of Clinical Trials. Proceedings of 10th Biennial Conference of the Manipulative Physiotherapists Association of Australia. Melbourne, Australia, 156-161, November, 1997.
Finds some support for the efficacy of McKenzie regimen, but the limited number of trials and their poor methodology make it impossible to draw firm conclusions.

Van Tulder Mw, Koes BW, Bouter LM: Conservative treatment of acute and chronic nonspecific low back pain. A systematic review of RCT of the most common interventions. Spine 22;2128-2156, 1997.
Probably the most thorough recent systematic review of a wide range of treatments. Amongst their findings - exercise therapy for acute back pain is ineffective; exercise therapy for chronic back pain is effective, but with no clear evidence in favour of any particular form of exercise.

Van Tulder M, Malmivaara A, Esmail R, Koes B: Exercise therapy for low back pain. A systematic review within the framework of the Cochrane collaboration back review group. Spine 25;2784-2796, 2000.
Review of 39 trials to judge effectiveness of exercise for acute and chronic back pain; with particular judgements about flexion, extension and strengthening exercises. Their conclusions are as above: exercise therapy is ineffective in acute stage, there is conflicting evidence on the value of exercise in the chronic stage, there is no evidence for the effectiveness of any specific exercise. (see correspondence)

REVIEWS
DiMaggio A, Mooney V: Conservative care for low back pain; what works? Journ Musculoskel Med 4:9;27-34, 1987.
A review of conservative therapy and an introduction to the McKenzie individualised prescription of exercises aimed at influencing the mechanical source of pain.

Fast A: Low Back Disorders: Conservative management. Arch Phys med Rehabil, Vol 69;880-891, 1988.
Following relevant anatomical considerations, the many causes of LBP are outlined. The McKenzie approach is included as one of the many conservative treatment measures.

Frost H, Moffett J K: Physiotherapy Management of Chronic Low Back Pain. Physiotheraphy 78:10;751-754, 1992.
A review of the psychological and physical benefits of an active, patient controlled treatment regime compared to passive modalities.

Huijbregts PA: Fact and fiction of Disc Reduction: A Literature Review. J Manual & Manip Therapy 6:137-143, 1998.
This review examines the effect of manipulation, traction, and McKenzie exercises on the position of herniated nuclear material in lumbar intervertebral discs. From the evidence reviewed the author concludes that there is no proof that rotatory manipulation is effective and may lead to further displacement; that traction may temporarily influence displacement; and that extension exercises may influence displacement in non-degenerated discs, but does not allow conclusions about the effect in degenerated or herniated discs.

McKenzie R A: REPEX in Acute and Subacute Low back Pain. In: Proceedings of Advances in Idiopathic Low Back Pain Symposium, Vienna, Austria, Nov 27-28, 1992. Ed Prof DDr E Ernst.
This article introduces the REPEX and includes a review of the use of end of range passive exercises and the literature pertaining to the method.

Mooney V: Herniated discs. In: Automated Percutaneous Lumbar Discectomy. Eds G Onik, C A Helms. San Fransisco: Radiology research and Education Foundation, 1988:53-70.
Mooney discusses herniated disc pathology and diagnosis, followed by conservative and surgical treatment options. The McKenzie method and studies that support it are included under conservative care.

TRIALS USING "MCKENZIE" OR FLEXION/EXTENSION REGIMES
Adams N.: Psychophysiological and Neurochemical Substrates of Chronic Low Back Pain and Modulation by treatment. Physiotherapy 79:2;86 (abstract), 1993
Chronic low back pain patients had decreased pain scale readings, increased lumbar range of motion, reduced EMG activity, and elevated levels of substance P following a 6 week treatment programme of McKenzie extension procedures.

Alexander A H, Jones A M, Rosenbaum Jr D H: Nonoperative Management of Herniated Nucleus Pulposus: Patient Selection by the Extension Sign - Long-term Follow-up. Orthopaedic Review 21;181-188, 1992.
Follow-up study of 33/73 patients with acute disc herniation treated conservatively. Those unable to gain extension by 5 days were treated surgically. Ability to regain extension was a better predictor of outcome than a variety of other clinical and neurological signs and symptoms.

Borrows J, Herbison P: ACC chronic backs study. Report of the evaluation of four treatment programmes. Accident Rehabilitation and Compensation Insurance Corporation (ACC), New Zealand.
Four rehabilitation programmes were compared. The McKenzie residential 9-day programme and one other non-residential one (104 days) produced significantly better outcomes in terms of those fit to work, and functional improvements at one month.

Buswell J: Low back pain: a comparison of two treatment programmes. NZ J of Physiotherapy 13-17
August, 1982.
Patients were treated by extension or flexion protocols, both produced significant improvements in patient outcomes, with no difference between the 2 groups.

Cherkin DC, Deyo RA, Battie MC, Street JH, Hunt M, Barlow W, A Comparison of Physical Therapy, Chiropractic Manipulation or an educational booklet for the treatment for low back pain. NEJM 339; 1021-1029, 1998.
McKenzie therapy and chiropractic manipulation are equally effective and both are slightly superior to the booklet in terms of patient satisfaction and short-term symptom reduction. The long-term outcome measures were the same in all 3 groups, including recurrences and care-seeking. The cost of the booklet group was considerably less than the 2 other groups.

Delitto A, Cibulka M T, Erhard R E, Bowling R W, Tenhula J A: Evidence for use of an extension-mobilization category in low back syndrome: a prescriptive validation pilot study. Physical Therapy 73:4;216, 1993.
Delitto suggests that treatment strategy based on signs and symptoms and response to movement may result in a more effective outcome compared with an unmatched non-specific treatment. Patients classified as extension-responders did better with an extension, than a flexion oriented programme.

Dettori JR, Bullock SH, Sutlive TG, Franklin RJ, Patience T: The Effects of Spinal Flexion and Extension Exercises and their Associated Postures in Patients with Acute Low Back Pain. Spine 20:21;2303-2312, 1995.
In the first week both exercise groups improved more than the control group. Subsequent to that there was no significant difference between the groups. Recovery of all groups was generally rapid, but recurrence was frequent.

Elnaggar I M, Nordin M, Sheikhzadeh A, Parnianpour M, Kahanovitz N: Effects of Spinal Flexion and Extension Exercises on Low-Back Pain and Spinal Mobility in Chronic Mechanical Low-Back Pain Patients. Spine 16:8;967-972, 1991.
Flexion and Extension exercises in a chronic low back pain population decreased pain levels and increased sagittal movement with no obvious preference to direction.

Erhard RE, Delitto A, Cibulka MT: Relative Effectiveness of an Extension Program and a Combined Program of Manipulation and Flexion and Extension Exercises in Patients with Acute Low Baxk Syndrome. Physical Therapy, 74:12;1093-1100, 1994.
Manipulation and general exercise group had greater improvements than pure extension group.

Faas A, Chavannes AW, van Ejik JTM, Gubbels JW: A Randomized, Pacebo-Controlled Trial of Exercise Therapy in Patients with Acute Low Back Pain. Spine 18:11;1388-1395,1993.
No differences in outcomes were found between groups receiving flexion exercises and advice, placebo ultrasound, or usual GP care.

Fowler B, Oyekoya O: The therapeutic efficacy of McKenzie concept in the management of low back pain. (abstract) Proceedings 12th International Congress World Confederation Physical Therapists, June 25-30, 1995, Washington DC, USA.
Retrospective case note review of 27 patients treated with McKenzie; 74% made rapid recovery.

Fredrickson B E, Murphy K, Donelson R, Yuan H: McKenzie Treatment of Low back Pain: a correlation of Significant Factors in Determining Prognosis. Annual meeting of International Society for the Study of the Lumbar Spine, Dallas Texas, USA, 1986.
In a large patient population, categorisation and treatment according to the McKenzie system is found to have definite prognostic value.

Gard G, Gille KA, Degerfeldt L: McKenzie method and functional training in back pain rehabilitation. A brief review including results from a four-week rehabilitation programme. Physical Therapy Reviews 5; 107-115, 2000.
Uncontrolled study of 40 patients treated with McKenzie and functional rehabilitation; 14 pain free afterwards. 36 /40 derangements; 18 / 36 demonstrated centralisation.

Gilbert JR, Taylor DW, Hildebrand A, Evans C: Clinical Trial of Common Treatments for Low Back Pain in Family Practice. BMJ 291;791-794, 1985.
Bed rest, flexion exercise group with advice, and control group all had similar outcomes.

Gillan MG, Ross JC, McLean IP, Porter RW. The natural history of trunk list, its associated disability and the influence of McKenzie management. Euro Spine J 7.6.480-483, 1998.
Patients with a trunk list were randomised to McKenzie protocol or non-specific back care. At 90 days there was a significantly greater reduction of list in the McKenzie group, but no clinical difference. List and functional disability were poorly correlated.

Goldby L (1995). A randomised controlled trial comparing the McKenzie method of mechanical diagnosis and therapy with a non-prescriptive exercise regime in the conservative treatment of chronic low back pain. Proceedings 4th McKenzie Institute International Conference, Cambridge, England, 16-17 September 1995.
36 patients randomised to McKenzie treatment or non-specific exercise - improvements both groups, significant differences in McKenzie group in pain, function, and health locus of control.

Kay MA, Helewa A: The effects of Maitland and McKenzie techniques in the musculoskeletal management of low back pain: A pilot study. Physical Therapy 74.5.S59 (abstract), 1994.
12 acute back pain patients randomly assigned to one of 2 treatment groups. At 3 weeks there were significant differences between the groups in pain, but not in mobility or disability. The McKenzie group improved by 18 units on a pain visual analogue scale, the Maitland group deteriorated by 16 units.

* Kopp J R, Alexander A H, Turocy R H, Levrini M G, Litchman D M: The use of Lumbar Extension in the Evaluation and Treatment of Patients with Acute Herniated Nucleus Pulposus. A preliminary Report. Clinical Orthopaedics 202:211-218, January 1986.
67 patients with disc herniations and nerve root signs were given extension exercises. Of those who improved, 34/35 (97%) achieved full extension. 32 came to surgery, of which only 2 (6%) were able to extend. The ability to achieve full passive extension correlated with good response to conservative treatment, and this was mostly achieved in a few days. Sequestrations were found in 56% of those who came to surgery.

NEW - Larsen K, Weidick F, Leboeuf-Yde C: Can passive prone extensions of the back prevent back problems? A randomized, controlled intervention trial of 314 military conscripts. Spine 27 (24) 2002: 2747-2752.
314 male conscripts randomised into 2 groups: one group received theory session based on TYOB, disc model, tape to back, and instructed to do 15 EIL X 2 a day for period of military duty. 214 (68%) completed follow-up at 12 months. 1-year prevalence LBP in experimental group 33%, compared to 51% in control. Numbers seeking medical help for LBP also significantly less (9% to 25%). In those who had reported LBP at baseline 1-year prevalence 45% to 80%.

Malmivaara A, Hakkinen U, Aro T et al: The Treatment of Acute Low Back Pain - Bed Rest, Exercises, or Ordinary Activity? New England J Med. 332:6;351-355, 1995.
Ordinary activity group had significantly better outcomes than those prescribed bed rest, or extension and lateral bending exercises.

Nwuga G, Nwuga V: Relative therapeutic efficacy of the Williams and McKenzie protocols in back pain management. Physiotherapy Practice 1:99-105, 1985.
A treatment trial of McKenzie versus Williams protocol favours the McKenzie approach in patients with a diagnosis of disc prolapse.

Owen JE, Orpen N, Ayris K, Birch NC: Very early McKenzie protocol intervention for back pain in hospital workers. JBJS 82B.Supp III. 212 (abstract), 2000.
Following introduction of a McKenzie trained therapist to manage hospital employees days lost due to back pain fell be 52%, number of staff off due to back pain fell by 27%, and number of episodes of absenteeism due to back pain fell by 30%.

Petersen, Kryger, Ekdahl, Olsen, Jacobsen (2002). The effect of McKenzie therapy as compared with that of intensive strengthening training for the treatment of patients with subacute or chronic low back pain. A RCT. Spine 27.1702-1709.
260 patients with chronic back pain followed up at 2 and 8 months after 8 week treatment period. With intention to treat analysis both groups improved modestly, McKenzie group favoured at 2 months. Outcomes were better and differences favouring McKenzie group were more significant in those who actually completed treatment.

Ponte D J, Jensen G J, Kent B E: A Preliminary Report on the use of the McKenzie protocol versus Williams Protocol in the treatment of Low Back Pain. Journ Orthop & Sports Phys Ther, Vol 6:2;130-139., 1984
In LBP patients, the McKenzie protocol was superior to the Williams protocol in decreasing pain and hastening the return of pain free range of motion.

Roberts A P: The conservative treatment of low back pain. (Thesis) Nottingham 1990.
At 7 weeks post onset of LBP, Roberts showed that the group receiving McKenzie treatment produced significant disability reduction compared with those treated with a NSAID (Ketoprofen).

Saal JA, Saal JS: Nonoperative treatment of herniated lumbar intervertebral disc with radiculopathy. Spine 14:4;431-437.
64 patients with herniated nucleus pulposus, including those with extrusions, were treated conservatively with a regime that included extension exercises, injections, lumbar stabilisation exercises, and a general exercise programme. The majority of patients had good or excellent outcomes, with failure to respond associated with stenosis.

Schenk R: A randomised clinical trial comparing therapeutic interventions for low back pain. Proceedings McKenzie North American Conference, Orlando, Florida, June 2-4, 2000.
25 of 34 patients classified as derangement randomly assigned to McKenzie exercises or mobilisation; significant differences in pain and function for McKenzie group after 3 sessions.

* Snook SH, Webster BS, McGorry RW, Fogleman MT, McCann KB: The reduction of Chronic Nonspecific Low Back pain through the control of early Morning Lumbar Flexion. RCT. Spine 23:2601-2607, 1998.
Education in the control of early morning flexion produced significant reductions in pain intensity, days in pain, disability and medication use. High drop-out rates show the difficulty of getting people to make such behavioural changes.

* Spratt KF, Weinstein JN, Lehmann TR, Woody J, Sayre H: Efficacy of Flexion and Extension Treatments Incorporating Braces for Low-Back Pain Patients with Retrodisplacement, Sponylolithesis, or Normal Sagittal Translation. Spine 18:13;1839-1849, 1993.
Improvement in the extension group was significantly greater, regardless of type of radiographic abnormality, than flexion or control group.

* Stankovic R, Johnell O: Conservative treatment of Acute Low-Back Pain. A Prospective Randomized Trial: McKenzie Method of Treatment versus patient Education in "Mini Back School". Spine 15:2, 1990.
100 acute back patients randomised to McKenzie or back school; significantly better outcomes in McKenzie group in pain, function, sick leave, recurrences, and further health care.

* Stankovic R, Johnell O: Conservative Treatment of Acute Low Back Pain. A 5-Year Follow-up Study of Two Methods of Treatment. Spine 20:4;469-472,1995.
Difference between 2 treatments at 5 years was much less, however McKenzie group had significantly less recurrences of pain and episodes of sick leave.

Timm KE: A randomised-control study of active and passive treatments for chronic low back pain following L5 laminectomy. JOSPT 20:276-286, 1994.
250 post-surgical patients with chronic back and thigh pain were randomised to 1) physical modalities, 2) manipulation and mobilisation, 3) EIS, EIL and spinal stabilisation exercises, 4) exercise machines and isokinetic training, 5) control group for 8-week period of treatment. In groups 3 & 4 there was a 20% improvement in Oswestry score, but no change in the other groups. Re-entry into treatment was at an average of 91 weeks (3) and 53 weeks (4), but 2-6 weeks in the other groups. Group 3 was most cost effective.

* Udermann B, Tillotson J, Donelson R, Mayer J, Graves J. Can an educational booklet change behaviour and pain in chronic low back pain patients? ISSLS, Adelaide, April 2000.
Nine months after reading Treat Your Own Back 81% of 62 recruits with chronic back pain of average 10 years duration were available. About 90% were still using posture and exercise advice from the book, 60% were free of pain, and another 22% had had less pain. Pain severity and number of episodes had significantly improved. Most attributed improvements to what they had learnt in the book.

Uderman B, Spratt K, Donelson R, Tillotson J, Mayer J, Graves J. Can an educational booklet change behavior and pain in low back pain patients? ISSLS, Edinburgh, April 2001.
Eighteen month follow-up to Udermann et al 2000, involving 54 patients. Over 90% still exercising and using posture. Showing long-term maintenance of symptom improvement.

Underwood MR, Morgan J. The use of a back class teaching extension exercises in the treatment of acute low back pain in primary care. Family Pract 15.1.9-15, 1998.
In an acute group of patients randomised to usual GP care or a one off back class according to McKenzie principles there were no significant differences in outcome, except one difference at one year, when more of the back class group reported 'back pain no problem in previous 6 months'.

Vanharanta H, Videman T, Mooney V: Comparison of McKenzie Exercises, Back Trac and Back School in Lumbar Syndrome; Preliminary Results. Annual Meeting of International Society for the Study of the Lumbar Spine, Dallas, Texas, USA, 1986.
138 patients allocated to McKenzie, traction, or back school; 97% of McKenzie group improved at one week, compared to less than 50%, with a significant difference at one month.

Weller M, Brotz D, Kuker W, Dichgans J, Gotz A: Mechanical physiotherapeutic diagnosis and therapy in patients with lumbar disc disease. Aktuelle Neurologie 28;74-81, 2001.
Uncontrolled study of 21 patients with confirmed disc prolapse treated with repeated active and passive movements selected according to symptom response; all patients were discharged improved, and most continued to improve.

Williams M, Grant R: Effects of a McKenzie spinal therapy and rehabilitation programme: preliminary findings. The Society for Back Pain Research (UK). Annual Scientific Meeting. (Abstract), 1992.
Significant change in pain, function and psychological status in chronic low back pain patients was found following a 2 week residential programme based on the McKenzie method of treatment.

Williams M M, Grant R N: A comparison of low-back and referred pain responses to end-range lumbar movement and position. Conference Proceedings of the International Society for the Study of the Lumbar Spine, Chicago, USA, May 20-24, 1992.
The importance of monitoring changes in the distal symptoms is highlighted in a prospective trial comparing two forms of repeated end range exercises.

Worsfold C, Langridge J, Spalding A, Mullee MA: Comparison between primary care physiotherapy education/advice clinics and traditional hospital based physiotherapy treatment: a randomised trial. Br J Gen Pract 46:165-168, 1996.
Spinal and non-spinal musculoskeletal problems managed in primary care with advice and exercise, which included exercises from Treat Your Own Back / Neck, were seen more efficiently than hospital physiotherapy (3 sessions compared to 5), and had better outcomes, though only a few were significant.

CENTRALISATION - LUMBAR & CERVICAL
* Donelson R, Murphy K, Silva G: Centralisation Phenomenon: Its usefulness in evaluating and treating referred pain. Spine 15:3, 211-213, 1990.
The centralisation phenomenon is found to be a reliable predictor of good or excellent treatment outcome. In 87 patients centralisation occurred in 87% - with centralisation occurring in 100% of 59 patients with excellent outcomes.

* Donelson R, Grant W, Kamps C, Medcalf R: Pain Response to Sagittal End-Range spinal Motion: A Prospective, Randomized Multicentered Trial. Spine 16:6S;S206-S212, 1991.
Donelson found that 47% of low back pain patients with or without referred pain displayed a directional preference to end range sagital spinal movement - 40% preferred extension, 7% preferred flexion.

* Donelson R G; Grant W D et al: Low Back and Referred Pain Response to Mechanical Lumbar Movements in the Frontal Plane. Presented at International Society for the Study of the Lumbar Spine Meeting, Heidelberg, May 12-16, 1991.
Centralisation can be achieved with end range frontal plane spinal movements in a majority of patients who failed to centralise with sagital plane movements.

Donelson R, Grant W, Kamps C, Richman P. Cervical and referred pain response to repeated end-range testing: a prospective, randomised trial. Nth Am Spine Soc. New York, 1997.
In patients with neck and referred symptoms 45% had pain reduced or centralised with sagital plane movements. Of this group 67% had a preference for extension and retraction and 33% had a preference for flexion and protrusion. In the remaining patients 14% showed a preference for extension, but not retraction, and 12% were worse with flexion, but not better with extension.

* Long A, The Centralisation Phenomenon. Its usefulness as a predictor of outcome in conservative treatment of chronic low back pain. Spine, 20, 23, 2513-2521, 1995.
A pilot study indicating that centralisation is useful as an outcome predictor in chronic patients. There was a superior outcome comparing centralisers to non-centralisers in an interdisciplinary work-hardening programme.

Karas R, McIntosh G, Hall H, Wilson L, Meles T: The Relationship Between Nonorganic Signs and Centraliazation of Symptoms in the Prediction of Return to Work for Patients with Low Back pain. Physical Therapy 77:4;354-360, 1997.
Inability to centralize indicated a decreased probability of returning to work, regardless of the Waddell score. A high Waddell score predicted a poor chance of returning to work regardless of the patients' ability to centralize symptoms. Waddell scores appear to be a better predictor of poor outcomes.

Lisi AJ: The centralization phenomenon in chiropractic spinal manipulation of discogenic low back pain and sciatica. J Manip & Physiol Thera 24;9, 596-602, 2001.
3 case studies demonstrating value of centralisation. 2 patients displayed centralisation and responded to mobilisation / manipulation treatment. One patient only able to peripheralise came to surgery.

* Sufka A, Hauger B, Trenary M, Bishop B, Hagen A, Lozon R, Martens B: Centralisation of Low Back Pain and Perceived Functional Outcome. JOSPT 27:205-212, 1998.
Of 36 patients 70% centralised within 14-day test period - centralisation was less amongst those with chronic symptoms and those with more referred pain. Centralisation was associated with significantly more improvement on one of the functional outcome measures used.

* Werneke M, Hart DL, Cook D: A descriptive study of the Centralisation Phenomenon. A Prospective Analysis. Spine 24.676-683, 1999.
Of 289 patients with acute neck and back pain 31% centralised during repeated movement testing in the clinic and achieved abolition of symptoms on an average of 4 sessions; 46% showed some centralisation or reduction of symptoms on an average of 8 sessions (partial response); 23% showed no change in symptom site or intensity over an average of 8 sessions. The authors question whether in the partial response group changes were a product of the natural history or exercise programme. Both centralisers and partial responders showed significant improvement in pain intensity and function, whilst the non-response group did not. Assessment of initial pain location was reliably assessed.

* Werneke M, Hart DL: Centralization phenomenon as a prognostic factor for chronic pain or disability. Spine 26.758-765, 2001.
In 225 patients with acute back pain 24 psychosocial, somatic and demographic variables were recorded at initial assessment. Patient outcomes at one year were predicted by a range of independent variables. When all these variables were entered in a multivariate analysis only pain pattern classification (centralisation or partial centralisation v non-centralisation), and leg pain at intake were significant predictors of chronic pain and disability.

* Williams M M, Hawley J A, McKenzie R A. Van Wijmen P M: A Comparison of the Effects of Two Sitting Postures on Back and Referred Pain. Spine 16:10; 1185-1191, 1991.
Over a 24-48 hour period 2 groups of patients with back and referred pain were encouraged to sit in lordosis or in a kyphotic posture. Lordotic sitting group had back and leg pain significantly reduced and pain centralised compared to kyphotic group.

SURVEYS OF MCKENZIE REGIMES & USE OF MCKENZIE METHOD
Battie MC, Cherkin DC, Dunn R, Ciol MA, Wheeler KJ: Managing Low Back Pain: Attitudes and Treatment Preferences of Physical Therapists. Physical Therapy 74. 219-226, 1994.
A survey of therapists in USA when presented with hypothetical back pain patients. The McKenzie method was deemed the most useful method of managing patients, and was said to be a very common means of evaluating patients.

Foster NE, Thompson KA, Baxter GD, Allen JM: Management of Nonspecific Low Back Pain by Physiotherapists in Britain and Ireland. A Descriptive Questionnaire of Current Clinical Practice. Spine 24.1332-1342, 1999.
The McKenzie method was said to be the second most common treatment approach used by therapists. The Maitland approach was used by 59%, McKenzie method by 47%,, multiple other approaches were used as well with less frequency - combined approaches were common.

Gracey JH, McDonough SM, Baxter GD: Physiotherapy management of low back pain. A survey of current practice in Northern Ireland. Spine 27;4,406-411, 2002.
Details of management of over 1,000 patients by 157 therapists over 12-month period. McKenzie was used in over 70% of patients, usually in combination, and was one of the most commonly used approaches. McKenzie course attendees ranged from 76% for A to 16% for D.

Jackson DA: How is low back pain managed? Retrospective study of the first 200 patients with low back pain referred to a newly established community-based physiotherapy department. Physiotherapy 87;11, 573-581, 2001.
In 58% of patients McKenzie approach was used, usually in combination with other therapies. Electrotherapy was commonly used also.

Laslett M, Michaelsen DJ, Williams MM: A survey of patients suffering mechanical low back pain syndrome OR sciatica treated with the "McKenzie method". NZ J Physiotherapy 24-32, August 1991.
A retrospective postal survey of patients' opinions about the success of treatment in dealing with their present pain, and enabling them to deal with recurrences showed high levels of satisfaction. Derangements 1 & 3 required fewer treatment sessions than Derangements 4,5,6.

McKenzie R A: Prophylaxis in Recurrent Low Back Pain. NZMedJ no 627, 89:22-23, 1979.
Frequent restoration of the lumbar lordosis and avoidance of flexion were seen as critical factors in prophylactic education for prevention of recurrent LBP. McKenzie reports on 318 patients - onset, aggravating and relieving factors, deformity, and the success of treatment in reducing further attacks as reported by the patients.

Rath W W, Rath J N D, Duffy C G: A comparison of Pain Location and Duration with Treatment Outcome and frequency. Presented at first international McKenzie Conference, Newport Beach, CA, July 1989.
Rath's retrospective study shows that 87% of lumbar and cervical pain patients had good outcome using the McKenzie method of treatment.

Rath W, Rath JD: Outcome assessment in clinical practice. McKenzie Institute (USA) Journal 4:3;9-16, 1996.
This retrospective study shows how neurological signs, chronicity of the problem, no centralisation, mechanically inconclusive findings on assessment, and positive behavioural signs tend to be associated with a less good outcome. This survey also reports on number of visits related to QTF categories, and the results of a telephone follow-up of patients at least a year after discharge asking about recurrences and ability to self-treat.

Sullivan MS, Kues JM, Mayhew TP: Treatment categories for low back pain: a methodological approach. JOSPT 24.359-364.
From this survey of PTs in USA 7 different treatment categories were proposed, which explained 62% of treatment variance. McKenzie treatment category was the most commonly used, explaining 21% of variance.

STUDIES INTO ASSESSMENT PROCEDURES, TESTS & TECHNIQUES
Axen, Rosenbaum, Robech, Wren, Leboeuf-Yde (2002). Can patient reactions to the first chiropractic treatment predict early favourable treatment outcome in persistent low back pain? J Manip Physiol Ther 25.450-454.
Prospective study of 615 patients receiving chiropractic manipulation relating initial response to final outcome - identifies symptom response as a prognostic factor. 84% of those who reported reduced pain after first session had 'definitely improved by 4th visit, compared to 30% in those showing no initial reduction.

Delaney PM, Fernandez CE:Toward an evidence-based model for chiropractic education and practice. J Manip & Physio Thera 22;114-118, 1999.
This commentary outlines the steps of evidence-based health care - formulating a question; searching the literature; critically appraising the literature; managing the patient accordingly; evaluating one's own practice. As an example of critical appraisal they examine Donelson (1997, see below) and conclude that the McKenzie protocol is a useful, highly sensitive, and moderately specific diagnostic tool for discogenic pain and annular incompetency.

Delaney PM, Hubka MJ: The diagnostic utility of McKenzie clinical assessment for lower back pain. J Manip & Physio Therapeutics 22; 628-630, 1999.
Re-analysis of Donelson (1997, see below) calculating accuracy of McKenzie assessment in diagnosis. Sensitivity and specificity for discogenic pain 94% and 82%; for incompetent annulus 100% and 86%. Compares favourably with most other established tests.

Donahue MS, Riddle DL, Sullivan MS: Intertester Reliability of a Modified Version of McKenzie' Lateral Shift Assessments Obtained on Patients with Low Back Pain. Physical Therapy 76:7;706-726, 1996.
Determination of a lateral shift by observation was found to be very unreliable. Determination of positive side-gliding test, based on alteration of patient's pain, was found to be of high reliability.

* Donelson R, Aprill C, Medcalf R, Grant W, A prospective study of centralisation of lumbar and referred pain. A predictor of symptomatic discs and anular competence. Spine, 22, 10, 1115-1122, 1997.
63 chronic patients received a mechanical evaluation and discography, with clinicians blind to the findings of the other assessment. Centralisation (74%) and peripheralisation (69%) were strongly associated with discogenic pain, compared to no change in symptoms (12%). Centralisation (91%) was strongly associated with a competent annulus compared to peripheralisation (54%).

Fiebert I, Keller CD: Are "passive" Extension Exercises Really Passive? JOSPT 19:2;111-115, 1994.
During EIL there is more EMG activity in the Erector Spinae muscles than during standing, EIS, or prone lying.

Fritz JM, Delitto A, Vignovic M, Busse RG. Interrater reliability of judgements of the centralisation phenomenon and status change during movement testing in patients with low back pain. Arch Phys Med Rehabil 81,57-61, 2000.
40 students and 40 physical therapists reviewed a composite videotape made during assessment of back pain patients and had to make judgements on changes in pain status with movement testing. Intertester reliability was excellent, kappa = 0.79.

George (2002). Characteristics of patients with lower extremity symptoms treated with slump stretching: a case series. JOSPT 32.391-398.
Out of 88 consecutive back pain patients 6 were identified who were considered appropriate for treatment by slump stretching - 4/6 would appear to fit category of ANR.

* Kilby J, Stigant M, Roberts A: The Reliability of Back Pain Assessment by Physiotherapists, Using a 'McKenzie Algorithm'. Physiotherapy 76:9;579-583, September 1990.
Kilby presents a McKenzie algorithm which was found to be intertester reliable, except with regard to identifying the presence of a lateral shift or a kyphotic lumbar spine.

Kilpikoski S, Airaksinen O, Kankaanpaa M, Leminen P, Videman T, Alen M: Interexaminer reliability of low back pain assessment using the McKenzie method. Spine 27;8,E207-E214, 2002.
39 patients with back pain were assessed by 2 therapists in turn, clinical and classification decisions were compared using Kappa statistics. Agreement was poorer for presence of lateral shift than relevance of shift or lateral component. Agreement on centralisation, directional preference, and mechanical classification was good to excellent.

Kilpikoski S: Intertester reliability in low back pain assessment using the McKenzie approach. Proceedings McKenzie North America Conference, Orlando, Florida, June 2-4, 2000.
39 patients assessed by 2 experienced therapists; good reliability for symptom response and classification, fair to moderate reliability for presence and direction of shift.

Laslett M, Williams M, The reliability of selected pain provocation tests for sacroiliac joint pathology, Spine, 19, 11, 1243-1249, 1994
Five of the seven tests were shown to be reliable, and may be used to detect a sacroiliac cause of low back pain. They were the distraction (or gapping) test, compression test, posterior shear (or thigh thrust) test, left and right pelvic torsion (or Gaenslen's) test.

McKenzie R A: Manual Correction of Sciatic Scoliosis. NZMedJ 484, 76:194-199, 1972.
McKenzie outlines the treatment procedure for manual correction of sciatic scoliosis.

McLean IP, Gillan MGC, Ross JC, Aspden RM, Porter RW: A comparison of methods for measuring trunk list. A simple plumbline is best. Spine 21:1667-1670, 1996.
Of 3 methods evaluated plumbline was the best, being reliable, simple to use, and accurate to within 4mm.

Mulvein K, Jull G: Kinematic analysis of the lumbar lateral flexion and lumbar lateral shift movement techniques. J Manual Manip Ther 3:3;104-109,1995.
Lateral shift technique (side gliding in standing) is found to produce movement with greater specificity to lower lumbar levels compared to lateral flexion. Above L4 either test movements can be used to examine movement abnormalities.

Pinnington MA, Miller JS, Rose MJ, Stanley IM, Rose GM: New episodes of back pain: how many patients can be classified into McKenzie syndromes? JBJS 82B.Supp III. 211-212 (abstract), 2000.
Of 522 new patients referred 307 (58%) were classified into McKenzie syndromes, while 215 (42%) were not. Significant differences were found between the groups in duration of episode, pain and disability scores, movement loss, and other variables.

Petersen T, Thorsen H, Manniche C, Ekdahl C: Classification of non-specific low back pain: a review of the literature on classification systems relevant to physiotherapy. Phys Ther Reviews 4:265-281, 1999.
A critical appraisal, using a systematic approach, of 8 classification systems for non-specific back pain. Various types of validity are examined, and despite having weaknesses in reliability and content validity, the McKenzie system is rated as one of the most promising.

* Razmjou H, Kramer JF, Yamada R: Intertester reliability of the McKenzie evaluation in assessing patients with mechanical low-back pain. JOSPT 30,368-389, 2000.
Two physical therapists, one assessor, one observer, both experienced in McKenzie assessed 45 subjects and were analysed on agreements using Kappa statistics. Agreement on syndromes was good (93%), derangement sub-syndrome classification was excellent (97%), presence of lateral shift was moderate (78%), relevance of lateral shift and lateral component was very good/excellent (98%), deformity in sagittal plane was excellent (100%).

Riddle D L, Rothstein JM: Intertester Reliability of McKenzie's classification of the type of the syndrome types present in patients with low back pain. Spine 18:10;1333-1344, 1993.
369 patients assessed by 49 therapists with no or minimal training in McKenzie. Intertester reliability using author's version of the system was poor, agreement on classification was 39%.

Riddle DL: Classification and Low Back Pain: A review of the literature and Critical Analysis of Selected Syndromes. Physical Therapy 78:7;708-737, 1998.
Critical analysis of various classification systems used for LBP, including McKenzie's. Highlights strengths and weaknesses of them according to an established set of criteria for appraising classification systems.

Roach KE, Brown M, Dumigan KM, Kusek CL, Walas M: Test-retest reliability of a low back pain questionnaire. Physical Therapy 74:5,S56, 1994.
Patient reports concerning leg pain were generally more reliable than back pain. Reports of back and leg pain, with one exception, had good reliability as examined using the Kappa coefficient.

Sallade J: Variation on Robin McKenzie's technique for correction of lateral shift. J Orth Sports Phys Ther 8:8;417-420,1987.
Author presents his own version of correcting the lateral shift with patient hanging by arms from overhead bar.

Spratt K F, Lehmann T R, Weinstein J N, Sayre H A: A New Approach to the Low-Back Physical Examination. Behavioural Assessment of Mechanical Signs. Spine 15:2, 1990.
The presence of various behavioural responses to pain during physical examination may help to determine outcome of treatment, endorse physical signs and confirm diagnosis. Used repeated movements for some tests. Intertester agreement for patient reported pain status was nearly perfect.

Stankovic R, Johnell O, Maly P, Willner S: Use of lumbar extension, slump test, physical and neurological examination in the evaluation of patients with suspected herniated nucleus pulposus. A prospective clinical study. Manual Therapy 4:25-32, 1999.
105 patients were diagnosed by CT and/or MRI as having disc hernia (N=52), bulging discs (41), or without positive findings (12). A range of clinical and physical examination findings was generally unable to distinguish between these diagnoses. The only 3 variables that were of diagnostic value were ROM on flexion, side bending, and pain distribution on EIS. Neurological tests, EIL (not reported if single or repeated), and SLR were amongst the numerous variables that failed to be associated with any particular diagnosis.

Tenhula JA, Rose SJ, DelittoA: Association Between Direction of lateral Shift, Movement Tests, and Side of symptoms in Patients with low Back Pain Syndrome. Physical Therapy 70:480-486, 1990.
There was no significant relationship between the side of symptoms and the direction of the shift. Contralateral side bending was significantly more likely to provoke symptoms than ipsilateral. There was perfect agreement on judging presence and direction of shift.

Weitz EM: The Lateral Bending Sign. Spine 6:388-397, 1981.
Study using dynamic lateral bending radiographs to localise disc lesions associated with a shift or reduced lateral bending.

Williams M M, McKenzie R A, Reed R, Laslett M: Responsiveness to Change of Three Disability Assessment Instruments for Back Pain Research. Presented at International Society for the Study of the Lumbar Spine Meeting, Heidelberg, May 12-16, 1991.
Williams concludes that with chronic back pain patients the Dallas pain questionnaire is most sensitive to small changes compared with the Rolland and Oswestry questionnaires.

Williams M M, Wright D G R, Mugglestone A A, Lynch G B, Spekreijse S A: Psychological distress in chronically disabled workers attending a McKenzie spinal therapy and rehabilitation programme. The New Zealand Pain Society. Annual Scientific Meeting. Conference proceedings (Abstract), 1993.
The Distress and Risk Assessment Method (DRAM) appears to have predictive value for treatment outcome in a chronically disabled low back pain population.

Young S, Aprill C: Characteristics of a mechanical assessment for chronic lumbar facet joint pain. J Manual & Manipulative Therapy 8.78-84, 2000.
Results of diagnostic injections (SIJ, facet, and disc) compared to mechanical evaluation involving McKenzie assessment, SIJ and hip tests in 93 chronic patients. Characteristics from mechanical assessment were compared in the different diagnostic groups.

ANATOMICAL PHYSIOLOGICAL & PAIN STUDIES
Adams MA, Hutton WC. Prolapsed intervertebral disc. A hyperflexion injury. Spine 10.184-191, 1982.
Cadaveric experiment simulating hyperflexion led to disc failure by posterior prolapse in 26 out of 61 motion segments tested.

Adams MA, Hutton WC. The effect of fatigue on the lumbar intervertebral disc. JBJS 65B.199-203, 1983.
Cadaveric experiment simulating a vigorous day's activity in flexion led to fatigue failure of annulus, with distortion of the lamellae and fissures in 23 out of 41 motion segments tested.

Adams MA, Hutton WC. Gradual disc prolapse. Spine 10.524-531, 1985.
Cadaveric experiment loading motion segments in compression and bending caused 6 out of 52 to gradual prolapse, starting with distortion of the lamellae and progressing to nuclear herniation. The most common mechanism of failure was end-plate fracture.

Adams MA, Dolan P. Recent advances in lumbar spinal mechanics and their clinical significance. Clin Biomech 10.3-19, 1995.
Comprehensive review of how spinal structures fail (over 200 refs) with emphasis on importance of mechanical loading in back pain. Discs particularly prone to fatigue failure.

Adams MA, May S, Freeman BJC, Morrison HP, Dolan P. Effects of backward bending on lumbar intervertebral discs. Relevance to therapy treatments for low back pain. Spine 25.4.431-437, 2000.
Cadeveric experiment in which the distribution of compressive stresses within 'degenerated' discs were measured by dragging a stress transducer through it. Extension caused an average increase in localised stress peaks in the posterior annulus, however in 7/19 discs extension caused a decrease in stress peaks by up to 40%. It was hypothesised that this reduction was due to stress shielding by the neural arch in more degenerated discs.

Al-Obaidi S, Anthony J, Dean E, Al-Shuwai N: Cardiovascular responses to repetitive McKenzie lumbar spine exercises. Physical Therapy 81: 1524-1533, 2001.
Blood pressure and heart rate goes up in normal individuals when they perform repeated exercises as described by McKenzie.

Beattie PF, Brooks WM, Rothstein JM et al: Effect of Lordosis on the Position of the Nucleus Pulposus in Supine Subjects. A Study Using MRI. Spine 19:18;2096-2102, 1994.
In vivo some anterior displacement of the nucleus pulposus with extension movements was observed. Degenerated discs appear to behave differently from non-degenerated discs.

Boissonnault W, Di Fabio RP. Pain profiles of patients with low back pain referred to physical therapy. JOSPT 24,4,180-191, 1996.
98 patients with chronic back pain surveyed about aggravating and relieving factors etc. Pain was worse in morning and evening, and commonest aggravating factors were sitting, driving, bending, and lifting. Commonest alleviating postures were recumbency, changing positions, and walking. Non-serious night pain was common.

Edmondston SJ, Song S, Bricknell RV et al: MRI evaluation of lumbar spine flexion and extension in asymptomatic individuals. Manual Therapy 5:3; 158-164, 2000.
Between flexion and extension there was anterior displacement of the nucleus pulposus of 6.7%, this was significant at L1/2, L2/3 and L5/S1. Displacement did not occur in 30% of discs.

Fennell AJ, Jones AP, Hukins DWL: Migration of the Nucleus Pulposus Within the Intervertebral Disc during Flexion and Extension of the Spine. Spine 21:23;2753-2757, 1996.
In vivo flexion tends to cause posterior displacement of the nucleus pulposus and extension anterior displacement using MRI.

Harrison DD, Harrison SO, Croft AC, Harrison DE, Troyanovich SJ: Sitting biomechanics, part 1: Review of the literature / Sitting biomechanics, part 2: Optimal car driver's seat and optimal driver's spinal model. J Manip & Physio Therapeutics 22: 594-609, 1999 / 23:37-47, 2000.
Extensive literature review on the biomechanical effects and comfort of different sitting postures to identify optimal seating and driving posture. Concludes that maintenance of lumbar lordosis, seat-back inclination, freedom to move, and minimal anterior head translation have been shown to reduce sitting stress and be associated with higher comfort ratings.

Kuslich, S D, Ulstrom C L, Michael C J: The Tissue Origin of Low Back Pain and Sciatica: A Report of Pain Response to Tissue Stimulation During Operations on the Lumbar Spine Using Local Anasthesia. Orthop Clinics of North America 22:2;181-187, 1991.
When mechanically stimulated during an operation the outer annulus, posterior longitudinal ligament, vertebral end plate, anterior dura and previously traumatised nerve roots, were all pain sensitive.

Magnusson M, Aleksiev AR, Spratt KF, Lakes RS, Pope MH: Hyperextension and spine height changes, Spine, 21, 22, 2670-2675, 1996
Hyperextension was demonstrated to be a beneficial movement to unload the spine after loading, aiding rehydration and concomitant improvement of disc nutrition.

NEW - O'Neill CW, Kurgansky ME, Derby R, Ryan DP: Disc stimulation and patterns of referred pain. Spine 27 (24) 2002:2776-2781.
25 patients who met inclusion criteria and who received intradiscal electrothermal annuloplasty (IDET) treatment for chronic discogenic back pain were studied for pain response to procedure. All pain provoked by procedure was familiar to patients - 16 had back pain only, 6 back and thigh, 3 radiated into calf. The distance pain was referred correlated to intensity of stimulus as measured by heat and duration, and always preceded in order back, thigh, then calf.

O'Sullivan PB, Grahamslaw KM, Kendell M, Lapenskie SC, Moller NE, Richards KV: The effect of different standing and sitting postures on trunk muscle activity in a pain-free population. Spine 27;1238-1244,2002.
Compared to erect sitting and standing most trunk muscle activity is significantly less in slumped sitting or standing.

* Pynt J, Higgs J, Mackey M: Seeking the optimal posture of the seated lumbar spine. Physio Theory & Practice 17;5-21, 2001.
A review of the literature on the optimal sitting posture for spinal health, based mostly on cadaveric studies, but some clinical studies. They conclude that the arguments in favour of a kyphotic sitting position are not substantiated by research; and that a lordotic position, interspersed with regular movement, is the optimal sitting posture and assists in preventing back pain.

Pynt, Higgs, Mackey (2002). Historical perspective. Milestones in the evolution of lumbar spinal postural health in searing. Spine 27.2180-2189.
Historical review of seating postures in the past, with analysis of what is deemed good posture from a recent evidence-based approach - favouring lordosis and interruption of sustained static sitting.

Reddeck T: An evaluation of the McKenzie regimen - validity of the disc model. Proceedings 10th Biennial Conference of Manipulative Physiotherapists Association of Australia. November 26-29, Melbourne, Australia, 1997.
This paper reviews the disc as a source of pain, the role of annular fissuring and displacement as a mechanism of pain production, and the relationship between the degree of disc pathology and the extent of symptoms.

Schnebel BE, Simmons JW, Chowing J, Davidson R: A digitizing technique for the study of movement of intradiscal dye in response to flexion and extension of the lumbar spine. Spine 13:3;309-312.
Nuclear material in normal discs moves anteriorly with extension and posteriorly with flexion, however movements in degenerated discs were less predictable.

Schnebel B E, Watkins R G, Dillin W: The Role of Spinal Flexion and Extension in Changing Nerve Root Compression in Disc Herniations. Spine 14:8;835-837, 1989.
Using cadaver models of herniated discs, Schnebel demonstrated that flexion increases tension and that extension decreases tension on the L5 nerve root.

Shepherd J: In vitro study of segmental motion in the lumbar spine. JBJS 77B: S2,161, 1995.
Intradiscal material generally moved anteriorly on extension and posteriorly in flexion, but amount varied amongst the specimens.

NEW - Van Deursen LLJM, Snijders CJ, Patijn J: Influence of daily life activities on pain in patients with low back pain. J Orthopaedic Med 24 (3) 2002:74-76.
4 GPs questioned 100 patients about back pain during 9 different postures / activities, to which patients could answer 'yes' or 'no'. Pain was reported as follows: sitting 85%, partly bent 78%, standing 73%, sit-to-stand 70%, sauntering 66%, fully bent 60%, lying 47%, walking 23%, cycling 15%.

Vanharanta H, Ohnmeiss D, Rashbaum R et al: Effect of Repeated Trunk Extension and Flexion Movements as seen by CT/Discography. Orthopaedic Transactions 12:3; 650-651, 1988.
No change observed in position of nucleus pulposus after flexion or extension.

OVERVIEWS OF MCKENZIE APPROACH
DiMaggio A, Mooney V: The McKenzie Program: Exercise effective against back pain. Journ Musculoskel Med 4:12;63-74, 1987.
The authors provide a review of the McKenzie assessment and treatment protocol and its rationale.

Donelson R: The McKenzie approach to Evaluating and Treating low back pain. Orthopaedic Review, Vol XIX, No 8, August 1990.
Donelson presents an overview of the McKenzie approach to low back pain treatment.

Donelson R G, McKenzie R: Mechanical Assessment and Treatment of Spinal pain. In: The Adult Spine: Principles and Practice. Editor-in-Chief J W Frymoyer. New York:Raven Press Ltd 1991. Vol Two, Chapter 76:1627-1639.
A review of the McKenzie assessment and treatment philosophy is provided along with a review of the relevant research pertaining to the method.

Donelson R G: Identifying appropriate exercises for your low back pain patient. Journ Musculoskel Med, pp 14-29, December 1991.
Donelson provides an overview of the McKenzie approach and reports on its success rates.

Grant R N, McKenzie R A: Mechanical Diagnosis and Therapy for the Cervical and Thoracic Spines. In: Clinics in Physical Therapy series: Physical Therapy of the Cervical and Thoracic spine, 2nd ed. Ed Prof Ruth Grant, University of South Australia.
An overview of the McKenzie approach with specific reference to the cervical and thoracic spine.

Hazard RG, McKenzie RA, Mooney V: Helping your back pain patients make the most of spinal motion. J Musculoskel Med pp24-35, January 1994.
Overview of benefits of activation, not rest. Includes active extension exercises, and continuous passive motion, achieved in lying on a repex machine and in sitting by a BackCycler.

Holdom A. The use of McKenzie approach to treat back pain. Br J Ther & Rehab. 3.1.7-10, 1996.
Overview of mechanical diagnosis, centralisation, force progressions, and value of approach in offering self-management.

Hyman MH, Jacob G, Lin K, Mooney V. Primary care update: brief summaries for clinic. Mechanical diagnosis and therapy: the McKenzie approach to spinal complaints. Consultant 39.7.2115-6, 1999.
Overview.

May S, McKenzie RA (2002). Mechanical diagnosis and therapy for the cervical and thoracic spine. In: Grant R (Ed), Physical Therapy of the Cervical and Thoracic Spine(3rd ed), Churchill Livingstone, New York.

McKenzie R A: Treat Your Own Back. Spinal Publications, Lower Hutt, N.Z., 1981.
A basic overview of the self-treatment and management of LBP for lay people.

McKenzie R A: Treat Your Own Neck. Spinal Publications, Lower Hutt, N.Z., 1983.
A basic overview of the self-treatment and management of neck pain for lay people.

McKenzie R A: The Lumbar Spine. Mechanical Diagnosis and Therapy. First Edition, Spinal Publications, Lower Hutt, N.Z., 1981.
A description of the McKenzie philosophy outlining assessment, treatment and prophylaxis for low back pain and leg pain.

McKenzie R A: Mechanical Diagnosis and Therapy for Low Back Pain: Towards a better understanding. In: Clinics in Physical Therapy. Physical Therapy of the Low Back, p157. Ed LT Twomey and JR Taylor. Churchill Livingstone, 1987.
McKenzie challenges the physiotherapy profession to critically look at the history of manipulative therapy, to learn from it, and to adopt a more organised rational approach to mechanical therapy.

McKenzie R A: The Cervical and Thoracic Spine. Mechanical Diagnosis and Therapy. First Edition, Spinal Publications (N.Z.) Ltd, Waikanae, New Zealand, 1990.
A revision and update of the McKenzie method of mechanical diagnosis and therapy with specific reference to the cervical and thoracic spine.

McKenzie R A: Mechanical Diagnosis and Therapy for Low Back Pain: Towards a better Understanding. In: The Lumbar Spine. Eds James Weinstein and Sam Weisel. Philadelphia: W B Saunders Company, 1990, Chapter 16, pp 792-805.
McKenzie reviews his classification system and emphasises the need for self-treatment.

McKenzie R A: A Physical Therapy Perspective on Acute Spinal Disorders. In; Contemporary Conservative Care for Painful Spinal Disorders: Concepts, Diagnosis and Treatment. Ed T G Mayer, V Mooney, R J Gatchel. Malvern, PA: Lea & Febiger, 1991, pp 211-220.
McKenzie compares his system of classification to the Quebec task Force findings.

McKenzie R A: Spinal Assessment and Therapy Based on the Behaviour of Pain and Mechanical Response to Dynamic and Static Loading. In: Proceedings of Advances in Idiopathic Low Back Pain Symposium, Vienna, Austria, Nov 27-28, 1992. Ed Prof DDr E Ernst.
A review of the Quebec Task Force findings and the McKenzie classification system, incorporating an introduction to the use of REPEX to facilitate the treatment process.

McKenzie R A: Mechanical Diagnosis and Therapy for Disorders of the Lower Back. In:Clinics in Physical Therapy. Physical Therapy of the Low back. 2nd ed. Eds L T Twomey and J R Taylor. Churchill Livingstone. 1994

Mooney V. Treating low back pain with exercise: the McKenzie approach. J Musculo Med 12.12.24-6,28,33-36, 1995.
Overview.

Moss JR (1994). Cervical and lumbar pain syndromes. In: Boyling JD, Palastanga N (Eds), Grieve's Modern Manual Therapy, Churchill Livingstone, Edinburgh.

Poulter D C, McKenzie R A: The Management of Work Related Back Pain. In: Patient Management. Auckland NZ: Adis International Medical Publishers.
The authors suggest common causes of LBP in the work place. They provide a review of tissue healing and suggest that self-treatment exercises can be used in the work place to prevent recurrence.

Robinson MG (1994). The McKenzie method of spinal pain management. In: Boyling JD, Palastanga N (Eds), Grieve's Modern Manual Therapy, Churchill Livingstone, Edinburgh.

Ross J: Management of the lateral shift of the lumbar spine. Manual Therapy 3;62-66, 1998.
Description of proposed mechanisms and correction of lateral shift.

Stevens B J, McKenzie R A: Mechanical Diagnosis and Self Treatment of the Cervical Spine. Clinics in Physical Therapy, Vol 17: Physical Therapy of the Cervical and Thoracic spine, ed Ruth Grant. Churchill Livingstone Inc, 1988.
A review of the McKenzie mechanical syndromes, patient evaluation, treatment progression, and prophylaxis as it pertains to the cervical spine.

Taylor MD. The McKenzie method: a general practice interpretation. The lumbar spine. Aust Fam Phys 25.2.189-201, 1996.
Overview of mechanical diagnosis and therapy in which the author proposes alternative nomenclature for mechanical syndromes - namely incipient trauma (posture), unhealed trauma (derangement), and healed trauma (dysfunction).

DISCUSSION ARTICLES
Jacob G:The McKenzie Protocol and the Demands of Rehabilitation. California Chiropractic Association Journal 16:10, October 1991.
Jacob likens the McKenzie approach and chiropractic approach and states that movement is the key to pain relief, either using patient generated forces or therapist generate forces when required.

Jacob G: Specific application of movement and positioning technique to the lumbar spine, considering theoretical formulation and therapeutic application. Today's Chiropractic, Part I, Vol 18, No 6; Part II, Vol 19, No 1, 1989-90.
The rationale for flexion procedures is outlined which has resulted in a failure to adequately explore the relationship of pain behaviour to movement and positions of the lumbar spine.

Jacob G: Spinal therapeutics based on responses to loading. 4th Mckenzie Institute International Conference, Cambridge, 16-17 September, 1995.
Discussion of mechanical and symptomatic responses to different loading strategies.

McKenzie R: A Perspective on Manipulative Therapy. Physiotherapy 75:8, 1989, pp 440-444.
McKenzie presents a review of spinal manipulative therapy and suggests that therapist generated forces should only be indicated when patient generated forces have been exhausted.

Mooney V: Reducing Subacute and Chronic Low back disability. Guest editorial in Orthopaedic Review, Vol XIX, No 8, August 1990.
Mooney concludes that active patient participation, early care and evaluation of function but not pain results in good outcomes when treating low back pain.

Watson G: Neuromusculoskeletal physiotherapy: Encouraging self-management. Physiotherapy 82:6;352-357.
Watson urges that physiotherapists should promote a therapeutic alliance with patients to encourage self-management, an approach that is efficient, increases patient compliance, and helps prevent recurrences.

CERVICAL SPINE
SYSTEMATIC REVIEWS
Aker PD, Gross AR, Goldsmith CH, Peloso P. Conservative management of mechanical neck pain: systematic overview and meta-analysis. BMJ 313.1291-1296, 1996.
Review of 24 RCTs: positive treatment effect for manual therapy from pooled results; for passive therapies, drug treatment and education results are contradictory and inadequate to reach conclusions.

NEW - Bronfort G, Assendelft WJJ, Evans R, Has M, Bouter L: Efficacy of spinal manipulation for chronic headache: a systematic review. J Manipulative & Physiological Therapeutics 24.457-466, 2001.
Review of 9 trials suggests manipulation may have short-term efficacy, but better research is needed.

Coulter I. Manipulation and mobilization of the cervical spine: the results of a literature survey and consensus panel. J Musculo Pain 4.113-123, 1996.
Review of 14 RCTs: for acute and chronic neck pain manual therapy may have some positive treatment effect, where tested exercises are as effective.

Di Fabio RP. Manipulation of the cervical spine: risks and benefits. Phys Ther 79.50-65, 1999.
Review of 12 RCTs: manual therapy has a positive treatment effect, with no proven difference between mobilisation and manipulation.

NEW - Hoving JL, Gross AR, Gasner D et al: A critical appraisal of review auricles on eth effectiveness of conservative treatment for neck pain. Spine 26.196-205, 2001.
25 review articles were included, 12 systematic reviews. Opinions varied in different reviews, regarding manipulation and traction there was inconclusive evidence.

Hurwitz EL, Aker PD, Adams AH, Meeker WC, Shekelle PG. Manipulation and mobilisation of the cervical spine. A systematic review of the literature. Spine 21.1746-1760, 1996.
Review of 14 RCTs, plus other studies, favouring short-term treatment effect of manual therapy.

Kjellman GV, Skargren EI, Oberg BE. A critical analysis of RCT on neck pain and treatment efficacy. A review of the literature. Scand J Rehab Med 31.139-152, 1999.
Review of 27 RCTs: positive outcomes and good quality studies supporting 'active' physiotherapy, manipulation, electromagnetic therapy.

TRIALS
* Abdulwahab SS, Sabbahi M. Neck retractions, cervical root decompression, and radicular pain. JOSPT 30.1.4-12, 2000.
In a group of patients with neck and radicular pain a posture of sustained flexion caused a significant increase in peripheral pain and root compression as measured by H reflex amplitude. Repeated retractions caused a significant decrease in peripheral pain and decrease of nerve root compression.

Hanten WP, Barrett M, Gillespie-Plesko M, Jump KA, Olson SL. Effects of active head retraction with retraction/extension and occipital release on the pressure pain threshold of cervical and scapular trigger points. Physio Theory & Pract 13.285-291, 1997.
One session of either intervention caused no significant changes in trigger point sensitivity.

Jull, Trott, Potter et al (2002). A randomized controlled trial of exercise and manipulative therapy for cervicogenic headache. Spine 27.1835-1843.
200 patients with cervical headaches randomised to manipulation, exercise, combined, or control group. 'Exercise' consisted of craniocervical flexion endurance exercises (ie retraction), postural correction exercises, and isometric rotation exercises. At 12 months all 3 active treatments significantly better than control, combined treatment better, but not significantly.

Schmidt I, Rechter L, Hansen VK, Therkelsen K, Rasmussen C: The association of the involvement of financial compensation with the outcome of cervicobrachial pain that is treated conservatively. Rheumatology 40: 552-554, 2001.
Of 60 patients with neck and arm pain treated with the McKenzie approach those involved in financial compensation showed no improvement, whilst those that were not showed a significant improvement.

See also Centralisation studies in lumbar section

ANATOMICAL, PHYSIOLOGICAL & PAIN STUDIES
Cloward RB: Cervical discography. A contribution to the aetiology and mechanism of neck, shoulder and arm pain. Ann of Surg 150:1052-1064,1959.
At surgery stimulation of cervical discs produced intra-scapular pain, with stimulation mid-line producing central pain and off-centre producing lateral pain.

Donelson R: Cervical protrusion and retraction. McKenzie Institute (UK) Newsletter 3:2;20-21,1994.
A radiographic and range of movement study of the effects of protrusion/retraction, and an analysis of symptom response to sagittal end-range test movements. Of the 45% who experienced improvement "directional preference" was for extension in 67%, and for flexion in 33%.

Harms-Ringdahl K. On assessment of shoulder exercise and load elicited pain in the cervical spine. Scand J Rehab Med S14.1-40, 1986.
Various motor and sustained loading tests carried out on asymptomatic volunteers. When sustaining extreme flexion pain was produced after 2-15 minutes and stopped test within hour, when the pain abated. Pain was mostly neck and shoulders.

Lentell, Kruse, Chock, Wilson, Iwamoto, Martin (2002). Dimensions of the cervical neural formina in resting and retracted positions using magnetic resonance imaging. JOSPT 32.380-390.
MRI study of neural foramina in 20 asymptomatic volunteers - retraction at most levels caused a slight but not significant enlargement of forminal area.

Mercer SR, Jull GA: Morphology of the cervical intervertebral disc: implications for McKenzie's model of the disc derangement syndrome. Manual Therapy 1:2;76-81, 1996.
As the morphology and degenerative process of the cervical spine is different from the lumbar spine the authors conclude that the model does not conform to known anatomy. (see also discussion McKenzie Institute (UK) Newsletter 5:1;10-14,1996)

Mercer S, Bogduk N: the ligaments and anulus fibrosus of human adult cervical intervertebral discs. Spine 24:619-628, 1999.
Anatomical study of 12 adult specimens. Anulus is thick anteriorly, but posteriorly is minimal, reinforced by the posterior longitudinal ligament centrally and virtually absent poster-laterally.

Ordway NR, Seymour RJ, Donelson RG, Hojnowski LS, Edwards WT: Cervical Flexion, Extension, Protrusion, and Retraction. A Radiographic Segmental analysis. Spine 24:240-247, 1999.
Study into the paradoxical movement pattern of the cervical spine - retraction produces lower C extension and upper C flexion, protrusion produces lower C flexion and upper C extension. Full range extension is produced in lower C by extension, but in O-C2 by protrusion; full range flexion is produced in lower C by flexion, but in O-C2 by retraction.

Pearson ND, Walmsley RP: Trial into the effects of repeated retractions in normal subjects. Spine 20:11;1245-1251,1995.
Retraction range did not increase on repetition, and range was greater in the younger population.

Schellhas KP, Smith MD, Gundry CR, Pollei SR: Cervical discogenic pain. Prospective correlation of MRI and discography in asymptomatic subjects and pain sufferers. Spine 21:3;300-312,1996.
Most cervical discs are morphologically abnormal, with outer annular tears found in both volunteers and patients. Gives areas of referral for discogenic pain.

WHIPLASH
REVIEWS
Barnsley L, Lord S, Bogduk N: Clinical review: Whiplash injury. Pain 58;283-307, 1994.
Thorough review of epidemiology, pathology, symptoms and litigation issue. Studies show that about a quarter will continue to have persistent pain.

Freeman MD, Croft AC, Rossignol AM; "Whiplash associated disorders: redefining whiplash and its management" by the QTF. A critical evaluation. Spine 23:1043-1049,1998.
Critical appraisal of Spitzer (1995) showing that their conclusion about the self-limiting/ favourable prognosis is not born out by the literature. In fact about 33% of whiplash patients have persistent pain several years later.

NEW - Magee DJ, Oborn-Barrett E, Turner S, Fenning N: A systematic overview of the effectiveness of physical therapy intervention on soft tissue neck injury following trauma. Physiotherapy Canada Spring 2000. 111-130.
Only 8 papers met validity criteria, these showed a weak to moderate positive effect for exercise, advice, manual therapy, and pulsed electromagnetic therapy. Quality of all papers very poor.

NEW - Peeters GGM, Verhagen AP, de Bie RA, Oostendorp RAB: The efficacy of coservative treatment in patients with whiplash injury. A systematic review of clinical trials. Spine 26:E64-E73, 2001.
11 studies met inclusion criteria all of poor methodology, only 3 were considered to have acceptable validity. Active treatment shows benefit long-term, whereas 'rest makes rusty'.

NEW - Scholten-Peeters GGM, Bekkering GE, Verhagen AP et al: Clinical practice guideline for the physiotherapy of patients with whiplash-associated disorders. Spine 27:412-422, 2002.
Active interventions, such as exercise, educational advice and normal activity are recommended.

Spitzer WO, Skovron ML, Salmi LR et al: Scientific Monograph of the Quebec task Force on Whiplash-Associated Disorders: Redefining Whiplash and its Management. Spine 20;1S-73S,1995.
An extensive review of the problem condoning an active, exercise, early return to normal function approach; stressing the self-limiting, favourable prognosis of the condition.

TRIALS
Borchgrevink GE, Kaasa A, McDonagh D et al: Acute treatment of whiplash neck sprain injuries. A randomised trial of treatment during the first 14 days after a car accident. Spine 23:25-31, 1998.
Continuing to engage in normal activities led to fewer symptoms than did sick leave and use of a collar.

* McKinney L A: Early mobilisation and outcome in acute sprains of the neck. Brit Med J 299:1006, 1989.
A single advice session produced fewer patients with persistent symptoms at 2 years than a course of manipulative physiotherapy. Prolonged collar wearing is associated with persistence of symptoms.

* McKinney L A, Dornan J O, Ryan M: The Role of Physiotheraphy in the management of acute neck sprains following road-traffic accidents. Archives of Emergency Medicine 6:27-33, 1989
Outpatient treatment and advice to mobilise earlier were both more effective than analgesics and a collar in treating acute neck sprains.

Mealy K, Brennan H, Fenelon GCC: Early mobilisation of acute whiplash injuries. BMJ 292: 656-657, March 1986.
Early active mobilisation and exercises produced significantly less pain and improved movement compared to rest and use of a collar.

* Rosenfeld M, Gunnarsson R, Borenstein P: Early intervention in whiplash-associated disorders. A comparison of two treatment protocols. Spine 25.1782-1787, 2000.
Nearly 100 acute patients randomised to one of 4 arms: active (1) or standard (2) treatment, within 96 hours (1a, 2a) or after 2 weeks (1b, 2b), with follow-up at 6 months. If symptoms persisted in active treatment group beyond 20 days a McKenzie assessment was conducted and specific, rather than non-specific exercises used. Active treatment was significantly better than standard (initial rest, collar, gentle movements), early treatment better than delayed. Minimal or no symptoms at follow-up: 1a: 10%, 1b: 53%, 2a: 41%, 2b: 86%.

CORRESPONDENCE
Cherkin study (1998). NEJM 340.5.388-391, 1999.

Delitto A, Cibulka M T, Erhard R E, Bowling R W, Tenhula J A: Author response. Physical Therapy 73:4;226, 1993.
The authors claim that they are testing the effect of treatment to a diagnostic classification, not the McKenzie method.

Donelson R, McKenzie R: Letter to the Editor, Spine 17:10;1267, 1992. In reference to the study by Elnaggar I M, et al: Effects of Spinal Flexion and Extension Exercises on Low-Back Pain and Spinal Mobility in Chronic Mechanical Low-Back Pain patients. Spine 16:8;967-972, 1991.
The authors explain that extension exercises have been used, not the McKenzie approach in comparison with spinal flexion exercises.

Fernando CK. Donelson R. Spine 16.1008-1009, 1991.
2 letters concerning Stankovic trial (Spine 15:120-123, 1990).

Long A: More on centralisation. JOSPT.29.8.489-490, 1999.
McKenzie R: Understanding centralisation. JOSPT 29;487-488, 1999.

Silva GJ. Riddle DL & Rothstein JM. Donelson R. Spine 19:12;1413-1415, 1994.
Correspondence concerning Riddle & Rothstein paper (Spine 18:1333-1344, 1993).

Van Tulder M, Malmivaara A, Esmail R, Koes B: Exercise therapy for low back pain. A systematic review within the framework of the Cochrane collaboration back review group. Spine 25;2784-2796, 2000. Commentaries on this review by Donelson, McKenzie, and May: Spine 26;1827-1831,2001.

Williams M M, McKenzie R A, Farrell J P: Commentaries. Physical Therapy 73:4;223, 1993.
McKenzie and Williams point out some inconsistencies and inadequacies with Delitta's study, but commend the authors on the study and agree that further research needs to be done.