1: Spine 2001 Apr
phenomenon as a prognostic factor for chronic low back pain and disability.
Werneke M, Hart DL.
NovaCare, Southern Ocean
Center for Health, Forked River, NJ 08731, USA. firstname.lastname@example.org
STUDY DESIGN: Two hundred twenty-three consecutive adults with acute low back
pain with or without referred spinal symptoms were treated conservatively and
followed prospectively for 1 year. OBJECTIVES: To investigate the predictive
value of centralization phenomenon (CP) with psychosocial variables
previously identified as important risk factors for patients with acute onset
of nonserious or nonspecific low back pain who subsequently develop chronic
pain or disability. SUMMARY OF BACKGROUND DATA: Psychosocial factors have
been shown to be predictors of chronic disability, but measures from physical
examination rarely predict chronic behavior. The authors of the present study
investigated whether dynamic assessment of changes in clinical measures
during treatment could be used to classify patients and predict occurrence of
chronic pain or disability. METHODS: Patients with acute symptoms and no history
of surgery were treated by five physical therapists trained in McKenzie
evaluation/treatment methods. Seventy-three percent were receiving workers'
compensation benefits. At initial evaluation and discharge, 23 independent
variables were assessed representing psychosocial, clinical, and demographic
factors. Pain location changes to repeated trunk movements were assessed at
every visit. Patients were placed in two groups: 1) those with pain that did
not centralize and 2) those who completely centralized or demonstrated
partial reduction of pain location with time. Treatment was individualized
and based on McKenzie methods. Patients were contacted at 12 months after
discharge, and dependent variables of pain intensity, return to work status,
sick leave at work, activity interference at home, and continued use of
health care were assessed. RESULTS: Nine independent variables influenced
pain symptoms or disability. Pain pattern classification (noncentralization)
and leg pain at intake were the strongest predictive variables of chronicity.
CONCLUSION: Dynamic assessment of change in anatomic pain location during
treatment and leg pain at intake were predictors of developing chronic pain
2: Spine 1999 Apr 1;24(7):676-83
descriptive study of the centralization phenomenon. A prospective analysis.
Werneke M, Hart DL, Cook D.
NovaCare at Southern Ocean Center for Health, Forked River, New Jersey, USA.
STUDY DESIGN: Occurrence and treatment responses associated with the
centralization phenomenon were analyzed prospectively in 289 patients with
acute neck and back pain with or without referred spinal symptoms. OBJECTIVES:
To document symptom changes to mechanical assessment during initial
evaluation and during consecutive visits. Using standard operational
definitions, patients were categorized reliably into three inclusive and
mutually exclusive pain pattern groups: centralization, noncentralization,
and partial reduction. It was hypothesized that the occurrence of
centralization would be less than previously reported and that the
centralization group would have better treatment results. SUMMARY OF
BACKGROUND DATA: Centralization has been reported to occur with high
frequency during mechanical assessments of patients with acute spinal syndromes.
When centralization is observed, a favorable treatment result is expected. Because
centralization has not been defined consistently in the literature, the true
prevalence and treatment responses associated with centralization have not
been confirmed. METHODS: Consecutive patients with neck or back pain
syndromes and referred to outpatient physical therapy services were
categorized into three pain pattern groups by experienced therapists trained
in the McKenzie system. Changes in distal pain location were scored and
documented before and after each visit. Maximal pain intensity over 24 hours,
perceived functional status, and number of treatment visits were compared
between groups. RESULTS: Patients could be categorized reliably according to
movement signs and symptoms. The centralization pain pattern group had
significantly fewer visits than the other two groups (P < 0.001). Pain
intensity rating and perceived function were different between the
centralization and noncentralization groups (P < 0.001). There was no
difference in treatment response between the centralization and
partial-reduction groups (P = 0.306). Prevalence of patients assigned to the
three groups was 30.8% in the centralization group, 23.2% in
noncentralization, and 46% in the partial-reduction group. CONCLUSION:
Categorization by changes in pain location to mechanical assessment and
treatment allowed identification of patients with improved treatment outcomes
and facilitated planning of conservative treatment of patients with acute spinal
pain syndromes. If a proximal change in pain location is not observed by the
seventh treatment visit, the results of this study support additional medical
evaluation for physical or nonphysical factors that could be delaying quick
resolution of the acute episode.
3: Spine 1995 Dec 1;20(23):2513-20;
centralization phenomenon. Its usefulness as a predictor or outcome in
conservative treatment of chronic law back pain (a pilot study).
Columbia Rehabilitation Centre, Calgary, Alberta, Canada.
STUDY DESIGN. Two-hundred-forty-three patients with chronic low back pain
were studied in a prospective comparative survey to determine whether the
"centralization phenomenon" was associated with outcome after an
interdisciplinary work-hardening program. OBJECTIVE. The hypothesis was that
patients who demonstrated centralization during initial mechanical assessment
would have better outcomes than noncentralizers. SUMMARY OF BACKGROUND DATA. Overall,
subjects had decreased pain intensity ratings (mean 20%), increased lifting
ability (6-8 kg), and a 59.2% return-to-work rate at a mean of 9.7 months
follow-up. METHODS. Patients were classified as either centralizers or
noncentralizers, based on results of their initial assessment. Changes in
pain ratings, one-time maximal weights lifted, Oswestry scores, and
return-to-work status were compared between groups. RESULTS. The centralizers
reported significant decreases in their maximum pain ratings (centralizers,
16%; noncentralizers, 6%) and had a higher return-to-work rate (centralizers,
68%; noncentralizers, 52%) than the noncentralizers. CONCLUSION.
Centralization can help identify sub-groups within the population with
chronic low back pain and could be a useful goal setting and case management
tool in the rehabilitation of low back pain.
4: Spine 1990 Mar;15(3):211-3
phenomenon. Its usefulness in evaluating and treating referred pain.
Donelson R, Silva G, Murphy K.
Department of Orthopaedics, State University of New York, Syracuse.
In patients with low-back and radiating leg pain, a clinical phenomenon has
been described known as "centralization," which occurs during a
mechanical evaluation protocol described by McKenzie. Relocation of the most
distal pain in a proximal or central direction characterizes the pain
behavior when patients are assessed in this fashion. Centralization typically
occurs rapidly and can be maintained. In a review of 87 such patients,
centralization occurred in 76 (87%). Its occurrence during initial mechanical
evaluation is a very accurate predictor of successful treatment outcome and
reliably determines the appropriate direction of treatment exercise. Nonoccurrence
of centralization accurately predicts poor treatment outcome and was a
helpful early predictor of the need for surgical treatment.