Introduction[edit | edit source]
Centralization is a clinical marker commonly used in the assessment of patients with spinal pain.  Centralization was originally noticed by Robin McKenzie in 1956, in the treatment of a patient with acute low back pain whose symptoms originating from the spine abolished and/or regressed as a result of an accidental therapeutic position.  Since then, it has been one of the key features of the McKenzie method  as well as other classification systems in the management of neck and low back pain.    The reverse of centralization, peripheralization, has also been described, as the phenomenon of pain (originating from the spine) spreading distally into the limb. 
Watch this video  on Centralization and Peripheralization:
Role of physiotherapy[edit | edit source]
Centralization is a clinically induced symptom response. This implies that centralization is a phenomenon which reflects immediate changes in symptom status after a physical examination or therapeutic method. Physiotherapists use a variety of tools i.e. positions, movement testing, manual tests to evoke this response; this is suggested to contribute to the assessment of the underlying acuity and nature of spinal symptoms,  the establishment of a diagnosis or prognosis,   or the determination of a management strategy.   
Here's an example of centralization being induced as a result of a physiotherapist's intervention :
Definition[edit | edit source]
Since the original report of centralization, there have been variations in the definition and the methods used to elicit centralization across studies.  Because these differences make the comparison of study findings, and inferences about the best definition to use difficult, the use of standardised criteria for centralization are commonly recommended. 
An international Delphi study was carried out to establish a uniform definition for centralization and operational criteria for eliciting this symptom response .  A broader definition of centralization was supported including "the progressive and stable reduction of the most distal pain towards the spinal midline in response to standardised repeated end-range movement or sustained loading testing procedures" with testing involving multiple strategies and/or alternative forces when appropriate,  indicating a mutual appreciation of the different but equally acceptable approaches when using this sign. This strategy reflects the clinical environment, where therapists may often combine approaches instead of exclusively following one system. 
Diagnostic value[edit | edit source]
Centralization has been reported to be present in approximately 40% of spinal pain cases.  Duration of symptoms determines its prevalence in patients, with acute populations reporting higher percentages (74%) than sub-acute and chronic patients (42%). 
Although centralization is suggested to indicate alterations in pain originating from the intervertebral disc, it has not been associated with the disc lesion type in patients with sciatica.  Another important feature of any clinical test is its reliability i.e. its ability to produce consistent and reproducible results among clinicians.  Centralization has produced variable reliability results and has yet to demonstrate adequate reliability across studies, but the influence of patient and clinician characteristics on these reliability outcomes needs further clarification. 
Prognostic value[edit | edit source]
Centralization has been cited and acknowledged as an important favourable prognostic indicator that should be routinely considered in this patient group.  Its presence has been common and associated with activity limitation and leg pain improvements in outcome measures of patients with sciatica, constituting an argument against a surgical option.  Nevertheless, these associations refer to short and medium term favourable outcomes  and there is limited evidence for areas other than the lumbar spine. 
Therapeutic value[edit | edit source]
Consistent evidence to imply that centralization is an important treatment indicator is still lacking.  However, the nature of most study designs incorporating it have not determined its presence at baseline, nor randomised patients accordingly. 
[edit | edit source]
Centralization is a clinical marker commonly used by physiotherapists in the assessment of patients with spinal pain. Its is more present in patients acute symptoms than sub-acute and chronic populations. Variations in the definition and the methods used to elicit centralization across studies have been noticed, and these differences make the comparison of and definite conclusions about study findings, as well as inferences about the best definition to use difficult. Nevertheless, centralization has been cited and acknowledged as an important favourable prognostic indicator; especially for short and medium term outcomes. To date, consistent evidence to imply that centralization is an important treatment indicator is still lacking.
References[edit | edit source]
- May S, Runge N, Aina A. Centralization and directional preference: an updated systematic review with synthesis of previous evidence. Musculoskelet Sci Pract 2018; 38:53-62.
- Donelson R. Rapidly reversible low back pain: an evidence-based pathway to widespread recoveries and savings. Hanover, NH: Self Care First, LLC, 2006.
- McKenzie R, May S. The lumbar Spine. Mechanical Diagnosis & Therapy. Volume One. Waikanae New Zealand: Spinal Publications, 2003
- Delitto A, Erhard R, Bowling R. A treatment-based classification approach to low back pain syndrome: identidying and staging patients for conservative treatment. Phys Ther 1995; 75:47-=485.
- Fritz J, Brennan G. Preliminary examination of a proposed treatment-based classification system for patients receiving physical therapy interventions for neck pain. Phys Ther 2007; 87:513-524.
- Murphy D, Hurwitz E. A theoretical model for the development of a diagnosis-based clinical decision rule for the management of patients with spinal pain. BMC Musculoskelet Disord 2007;8:75.
- Tauzell R. Centralization and Peripheralization. Available from: https://youtu.be/mTX2ZU7XghA (accessed 22/4/2022)
- Kuhnow A, Kuhnow J, Ham D, Rosedale R. The McKenzie method and its association with psychosocial outcomes in low back pain: a systematic review. Physiother Theory Pract 2021; 37:1283-1297.
- Albert H, Hauge E, Manniche C. Centralization in patients with sciatica: are pain responses to repeated movement and positioning associated with outcome or types of disc lesions? Eur J Spine 2012; 21: 630-636.
- Pinto D, Cleland J, Palmer J, Eberhart S. Management of low back pain: a case series illustrating the pragmatic combination of treatment - and mechanism - based classification systems. J Man Manip Ther 2007; 15: 111-122.
- Al-Obaidi S, Nakhi H-B, Skaria N. Effectiveness of McKenzie intervention in chronic low back pain: a comparison based on the centralization phenomenon utilizing selected bio-behavioural and physical measures. Int J Phys Med Rehabil 2013; 1:1-8.
- Physical Therapy Nation. Explaining centralization. Available from: https://www.youtube.com/watch?v=mNoYEZltG8o(accessed 25/4/2022)
- Berthelot J-M, Delecrin J, Maugars Y, Passuti N. Contribution of centralization phenomenon to the diagnosis, prognosis, and treatment of diskogenic low back pain. Joint Bone Spine 2007; 74:319-323.
- Werneke M, Hart D, Resnik L, Stratford P, Reyes A. Centralization:prevalence and effect on treatment outcomes using a standardized operational definition and measurement method. J Orthop Sports Phys Ther 2008; 38:116-125.
- Chorti A. Towards a uniform definition for the centralisation phenomenon. PhD thesis. Coventry: University of Warwick, 2009.
- May S, Aina A. Centralization and directional preference: a systematic review. Man Ther 2012; 17:497-506.
- Sim J, Wright C. Research in healthcare:concepts, designs and methods. Cheltenham, Nelson Thornes, 2000.
- Werneke M, Hart D, Cutrone G, Oliver D, McGill M-T, Weiberg J, et al. Association between directional preference and centralization in patients with low back pain. JOSPT 2011; 41:22-31.
- Edmond S, Cutrone G, Werneke M, Ward J, Grisby D, Weinberg J, et al. Association between centralization and directional preference and functional and pain outcomes in patients with neck pain. JOSPT 2014; 44:68-75.
- Gregg C, McIntosh G, Hall H, Hoffman C. Prognostic factors associated with low back pain outcomes. J Prim Health Care 2014; 6:23-30.
- Rose T, Butler J, Salinas N, Stolfus R, Wheatley T, Schenk R. Measurement of outcomes for patients with centralising versus non-centralising neck pain. J Man Manip Ther 2016; 24:264-268.
- Surkitt L, Ford J, Chan A, Slater S, Pizzari T, Hahne A. Effects of individualised directional preference management versus advice for reducible discogenic pain: a pre-planned secondary analysis of a randomised controlled trial. Musculoskel Sci Pract 2016; 25:69-80.
- Werneke M, Edmond S, Young M, Grigsby D, McClehanan B, McGill T. Directional preference and functional outcomes among subjects classified at high psychosocial risk using STarT. Phys Res Int 2018; 23:e1711.
- Yarznbowicz R, Tao M, Owens A, Wlodarsky M, Dolutan J. Pain pattern classification and directional preference are associated with clinical outcomes for patients with low back pain. J Man Manip Ther 2018; 26:18-24.
- Runge N, Aina A, May S. Are within/and/or between session improvements in pain and function prognostic of medium and long-term improvements in musculoskeletal problems? A systematic review. Musculoskelet Sci Pract 2020; 45:
- Chorti A, Chortis A, Strimpakos N, McCarthy C, Lamb S. The prognostic value of symptom responses in the conservative management of spinal pain: a systematic review. Spine 2009; 34:2686-2689.