Clinicians
The McKenzie Method® of Mechanical Diagnosis and Therapy®
Systematic review of 14 studies into centralisation. Prevalence 70% in 731 sub-acute back pain patients and 52% in 325 chronic back pain patients. Centralisation was reliably assessed (kappa values 0.51 to 1.0). Centralisation was consistently associated with good outcomes, and failure to centralise with poor outcomes. Association was confirmed by high quality studies.
Comparison of outcomes in 2 groups of patients with chronic low back pain who demonstrate complete (N =62) or partial centralization (N=43), and followed-up over 10 weeks with treatment with MDT. The groups were significantly different at baseline in terms of fear-avoidance and Roland-Morris Back Disability questionnaire. Over time both groups had highly significant changes in all outcomes relating to pain perception, fear beliefs, disability beliefs and physical performance tests, but were better in the full centralization group.
Secondary analysis of previous RCT; 176 patients with sciatica and pain below the knee given a mechanical assessment and classified: 85% reported centralization, 7% peripheralization, and 8% no effect in response to repeated movements. Leg pain was significantly better in the centralization and peripheralization groups at 3 and 12 months. Centralization occurred in all types of disc lesions reported on MRIs, from normal through to sequestrations.
View article source54 patients were randomly allocated to McKenzie method or guideline-based treatment, and final assessments were taken at the end of one week. There were significant differences in centralisation in the McKenzie group (62% versus 17%), but no difference in other outcomes (Oswestry and pain intensity) ( In French).
Follow-up of previous study in which patients with lumbar herniations and demonstrating centralisation predicted good long-term outcome in the majority of patients.
42 patients with back pain were classified as centralised (30), centralising (3), non-centralised (9); there were significant differences between initial and final extension range in first 2 groups, but not in the latter. Patients who showed centralisation on initial visit also showed an increase of ROM during initial visit.
Occurrence of centralisation was correlated with occurrence of pain during movement in 33 patients with back pain. 22 (67%) reported centralisation, 8 (24%) centralising symptoms, and 3 (9%) reported no site change in symptoms; and 29 reported pain during movement. 97% of those who reported pain during movement reported centralisation/centralising; and 93% of those who reported centralisation/centralising reported pain during movement (p=0.001 for both).
Cross sectional study looking at centralisation status and psychological factors in 331 patients with back pain. Centralisation occurred in 30% of their sample. There were significant associations between non-centralisation and mental distress and depression.
A cohort study running alongside a RCT of over 300 patients who were sick-listed for back pain and assessed for the presence of centralisation; with primary outcome being return to work. Following mechanical evaluation 30% were classified as centralisers, 8% as peripheralisers, and 62% as no response. All groups improved over the year, with no significant differences between pain response groups.
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%).
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.
304 patients with neck pain were included, and prevalence rates of 40% for centralization and 70% for directional prevalence were recorded. Neither were associated with pain outcomes, but directional preference and to a lesser extent, centralization, were associated with improvements in function. Younger subjects were more likely to centralize, and those with acute symptoms more likely to demonstrate directional preference.
Secondary analysis of cohort study of 231 patients with back pain in which data was gathered about depression, somatization, and centralization at baseline, and measures of disability and pain at baseline and follow-up. Associations between depression and somatizisation and chronic disability were reduced in the presence of centralization.
Secondary analysis of 28 patients who were classified as specific exercise category and observed for the effects of prognostic variables at baseline on outcomes at 6 months. Centralisation and fear-avoidance at work both independently and significantly predicted disability at 6 months. Only centralisation significantly predicted pain at 6 months.
Retrospective analysis of 1076 patients treated over 3 years with multivariate analysis to determine prognostic factors that were associated with outcome. Shorter duration of pain, lower baseline pain, intermittent pain, and a directional preference for extension were all associated with better outcomes.
Comparison of muscle activity in centralizers and healthy controls, with the latter showing significantly lower erector spinae activity. Following centralization pain, disability, and erector spinae were all reduced.
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.
Secondary analysis looking at outcomes in a group of patient with centralisation randomised to McKenzie, orthopaedic manual therapy (OMT) or advice to stay active. The McKenzie group had some significantly better outcomes after treatment and at 3 and 6 months than the advice group, but at one year there were no significant differences between the groups. There were few significant differences between the 2 active treatments (McKenzie group less leg pain at 3 months) or between OMT and the advice only group (OMT group less back and leg pain at 6 months).
Secondary analysis of previous RCT (Paatelma et al. 2008) in which baseline centralizers (N=119) were compared to baseline non-centralizers (N=15) during follow-up. Centralizers had a significantly greater reduction in pain and disability immediately after the treatment period; and at 6 months for pain only. (In German)
83 patients with chronic low back pain underwent a full or partial mechanical examination and discography and the results were compared. The prevalence of positive discography was 75%, and of centralisation 32%. Sensitivity of centralisation to predict discogenic pain was weak (about 40%), but specificity was high and 100% in patients without severe distress or disability.
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.
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.
Secondary analysis from a previous trial (Long et al 2004) of 312 patients who received a mechanical evaluation at baseline, 84 were deemed to have a good outcome (defined as at least 30% reduction in baseline Roland-Morris score). Factors that were predictive of a good outcome were analysed using multivariate analysis. Only leg bothersomeness rating and treatment assignment survived multivariate analysis. Subjects with directional preference who received matched directional treatment were 7.8 times more likely to have a good outcome, which was a stronger predictor than a range of other biopsychosocial factors.
View article sourceThe review included 54 studies relating to centralization and 8 relating to directional preference exercises. The prevalence on centralization was 44% in back and neck pain, with higher prevalence in acute (74%) than sub-acute or chronic symptoms (42%). Twenty-one of 23 studies supported the prognostic validity of centralization, whereas 2 did not. Centralization and directional preference appear to be useful treatment effect modifiers in 7 of 8 studies. Levels of reliability were very varied (kappa 0.15-0.9).
Assessment of 264 consecutive patients using previously described algorithm found that 2.7% had serious pathology and 41% showed centralization. According to definitions used 23% / 27% / 24% showed lumbar, sacroiliac segmental signs (pain provocation tests) and radicular signs respectively. In 63% and 40% dynamic instability and fear beliefs were respectively diagnosed.
Data on 95 patients with neck pain on their classification according to the diagnosis-based clinical decision guideline previously published. Potential serious illness was found in 1%, centralization in 27%, segmental pain provocation signs in 69%, and radicular signs in 19%.
Use of a classification system that included centralisation as initial part of algorithm, after exclusion of serious pathology, in a cohort with pregnancy related back pain, of which 58% was pelvic pain, 20% back pain and the rest a mixture. Proportion with each classification is not given.
Report on consecutive cohort study of patients with lumbar radiculopathy of who 62% demonstrated centralisation with repeated movements, and 8% peripheralisation. Centralisation was associated with functional improvement, especially at long-term follow-up.
Application of a diagnosis-based classification system (not MDT) in 95 patients with neck pain; centralization was found in 27%. Larger proportions had segmental pain provocation signs, myofascial sign sand dynamic instability according to the study criteria. Classifications were not mutually exclusive.
66 French certified McKenzie therapists each collected data on 10 consecutive patients, providing data on 349 patients with back pain. At baseline 92% were classified with Derangement, 2.3% with Dysfunction, 0.9% with Postural, and 4.9% with Other. Centralization was recorded in 70.5% at baseline, which increased to 73.5%, and Directional Preference remained at 73.5%. Between baseline and the fifth session the classification remained the same in 90.1%. Directional preference was as follows: extension 79.5%, lateral 12.6%, and flexion 4.3%.
View article sourceCase study of patient with cervical radicular pain, demonstrating centralisation in response to retraction and extension, categorised as derangement and treated with retraction and extension exercises.
Cohort study of 34 acute to chronic patients treated with McKenzie approach, with significant improvements in pain and range of movement: 61.5% demonstrated centralisation.
60 patients with referred symptoms and sciatica following a mechanical evaluation were classified as centralisers (25) or non-centralisers (35). Patients then followed a standardised management pathway that involved surgery if there was a failure to improve. Both short and long-term the centralisation group had significantly better outcomes for pain and disability. Non-centralisers were 6 times more likely to have surgery.
Review and commentary about using patient responses as a guide to clinical reasoning. Changes in range of movement and centralisation of symptoms are better indicators of treatment effectiveness than changes in pain intensity or changes in joint position. Limited evidence to support the use of changes in segmental stiffness to guide management.
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.
Report of over 350 spine patients; 76% lumbar, 53% chronic symptoms (> 3 months), mean age 58 years. Overall rate of centralization at intake as measured on a body chart template was 17%, with higher rates in more acute and younger patients. For instance rates were 29% and 24% for acute (< 3 weeks) lumbar and cervical patients, and 32% and 30% for lumbar and cervical patients aged between 18 and 44. Centralization was much less common in those with chronic symptoms and those over 64 for lumbar problems and over 44 for those with cervical problems. Outcomes were better amongst centralizers and outcomes were worse amongst non-centralizers.
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.
Re-analysis of data from earlier study comparing prognostic usefulness of classifying patients as centralisers on the first visit compared to during subsequent visits. At first visit 130 (45%) were classified as centralisers, only 4 became non-centralisers, but 43 became partial centralisers. At first visit 157 (55%) were classified as non-centralisers _x0013_ of these 95 (60%) became partial or full centralisers at later sessions.
Data collected on 628 patients from 8 different clinics by therapists with training in MDT found prevalence of derangement (67%), dysfunction (5%), and posture syndrome (0%); centralisation (43%), non-centralisation (39%), and not classified (18%); and positive to manipulation (13%) and stabilisation (7%) clinical prediction rules. Derangement classification and centralisation prevalence was high in patients who fulfilled both clinical prediction rules.
Re-analysis of data from 586 patients with back pain; patients who demonstrated non-centralization (37%) had significantly worse pain, functional disability and psychosocial distress outcomes compared to those who centralized (45%). No pain pattern classification was recorded in 18%.
Secondary analysis looking at predictors of outcome in 238 patients with back pain: 18% centralisers, 52% non-centralisers, and 30% could not be classified; 56% had low fear avoidance, 44% had high fear avoidance. Treatments depended on classification according to these variables. Patients who demonstrated centralisation improved most whatever their levels of fear avoidance; those with high levels of fear avoidance improved least. Both centralisation and fear-avoidance levels impacted on outcomes.
Re-analysis of data from previous study to determine association between centralisation category and psychosocial variables. Non-centralisation patients were significantly more likely to have positive non-organic signs, overt pain behaviour, fear of work activities and somatisation, but no difference was found between centralisation category regarding depression, fear of physical activity, disability or pain intensity.
Re-analysis of previously collected data comparing different methods of classifying back pain patients for their ability to predict outcome. QTF 3 or 4 predicted high levels of pain and disability at intake, but only centralisation / non-centralisation categories predicted pain and disability at discharge. Non-centralisation was stronger predictor of work status at 1 year than fear-avoidance. Predictive value of centralisation / non-centralisation stronger when followed through rehabilitation period, than just at intake.