“Therapists using the McKenzie method classify patients based on repeated end-range trunk movement tests into 1 of 3 main syndromes: derangement, dysfunction and posture.”
There is a lot here even though they summarized it very succinctly. By the by, one of the authors, Jason Ward, has an awesome podcast called the Mechanical Care Forum that you guys should all check out. He delves into the topics of Mechanical Diagnosis and Therapy mostly, but also has other guests on the show such as Stu McGill, Mulligan (no need for a first name) and others.
MDT is a systematic assessment process in order to classify patients into one of three categories. The derangement category has the hallmark sign of centralization and peripheralization. This is being taught in schools with much evidence to support it for good outcomes. RANT: When I was in school this was barely touched upon and MDT was only one of the methods that a person may be exposed to upon graduation. I recently visited Governors State University and was pleased to see that they have added centralization/peripheralization, directional preference and repeated movement exams into the curriculum. The derangement syndrome is classified by rapid change, for better or worse, either symptomatically or mechanically (range of motion, reflex, strength change, sensation changes). The derangement syndrome is the most prevalent syndrome classification in MDT.
The second most common syndrome is the dysfunction syndrome. This is further subclassified into two parts: articular dysfunction and contractile dysfunction. Starting with a contractile dysfunction, it is as simple as the name denotes. It is a dysfunction of some of the contractile tissues of the body and is named for the direction of dysfunction. For instance, if there is a “muscle strain” of the shoulder flexors, the patient would demonstrate with pain during contraction of the muscle with pain increasing with increasing load and also pain during the stretch of this muscle. This is a contractile dysfunction into shoulder flexion.
One could also have an articular dysfunction, which is a dysfunction of non-contractile tissues. This could be any structure that doesn’t contract, but the joint capsule is one of the structures typically referred to. A deficit in the non-contractile structures should cause a joint to be limited in its range, but not with regards to its strength. The hallmarks of the dysfunction syndrome are both a lack of dramatic change and consistency with regards to the limitation.
“The patient may also be categorized ino an “other” category (eg, chronic pain syndrome, surgery, mechanically inconclusive, spinal stenosis, spondylolisthesis, hip, sacroiliac joint dysfunction, and other)if the patient cannot be successfully classified into 1 of the 3 main McKenzie syndromes”
I wrote a case series a couple years back that I am working to get published regarding cancer causing back pain. This would be an “other” category. It doesn’t fit one of the 3 presentations and would have to be classified as other and wouldn’t fit into the treatment paradigm for MDT.
“Within the McKenzie classification system, evidence supports the prognostic relevance and discriminative utility of 2 pain-pattern classification criteria: centralization and directional preference…Briefly, centralization is characterized by spinal pain and referred spinal symptoms that are progressively abolished in a distal-to-proximal direction in response to therapeutic movement strategies. Directional preference has been defined as a specific movement or posture that decreases the patient’s pain, with or without the pain having changed location, and/or increases the patient’s lumbar range of motion”
Where to start? Centralization…there has been much work by Werneke and Hart regarding centralization’s prognostic value for both positive and negative. Also, Skytte 2005ish has an article that reveals that a lack of centralization leads to a 600% increase in the need for invasive procedures. https://www.ncbi.nlm.nih.gov/pubmed/15928538
If you don’t know the story behind Mr. Smith, I will tell it to the best of my recollection. Robin McKenzie, the founder of MDT, had a patient come into the clinic in New Zealand in the 1950’s with back pain that radiated into the leg. Mind you, patients at this time were only performing flexion based exercises (knees-to-chest or chest-to-knees) and extension based exercises (back bends or press-ups) were thought to sever the nerves of the spine if one performed the exercises too aggressively. Hence, they were avoided. Walks in Mr. Smith. Robin was a great therapist and thus he was also a very busy therapist. Robin told Mr. Smith to go into the room and lie down on his belly, forgetting that he had the table positioned in such a manner that the head of the bed was elevated. What this means is that when Mr. Smith was on the table, he was in extension. Robin was so busy in the clinic that he was unable to get to Mr. Smith immediately. In essence, Mr. Smith spent a prolonged period of time in extension. His symptoms rapidly abolished in his leg and he only had back pain remaining. Robin saw this and made an attempt to understand the phenomenon. This lead to 50 years of studying pain patterns until the dynamic disc theory was finally being confirmed in the research. Mr. Smith and Robin effectively changed the way that spines are treated and because of this, Robin was ranked the most influential therapists in the 1900’s by the orthopedic section of the APTA.
Directional preference was termed by Dr. Ron Donelson, also author of Rapidly Reversible Back Pain (a good read, but at times boring). A person can have a directional preference in the absence of centralization. There may be a change in mechanical responses prior to a report of centralization, also there are studies documenting directional preferences in joints outside of the spine.
“…retrospective analysis of a longitudinal, observational cohort was conducted”
This is fancy speak, but the words are important. This means that the researchers observed what happened over the course of time (observational longitudinal), but the information is from a time period prior to actually initiating the study (retrospective). The reason why it’s important is because patient consent is not needed for this type of study, since the treatment was unchanged from what a therapist would do compared to an interventional study in which a person is trying to prove or disprove something is effective.
“Patients were classified at intake into the subgroups of centralization, noncentralization, or not classified…using a body diagram”
Not all patients will centralize at the time of the initial evaluation. If they do centralize and remain centralized, this is a great sign, but some patients may require up to 7 days in order to centralize, as noted by one of the Werneke studies.
“Treatment processes were guided by the patient’s symptomatic and mechanical responses to continual assessments of repeated movements, positioning, and/or manual techniques. If centralization or directional preference was observed, treatment was standardized following MDT assessment and treatment methods.”
The problem with this system is that it is elusively easy to use. If during the session, we find movements, positions, or postures that make your symptoms worse, we educate you to discontinue or avoid those positions TEMPORARILY. When we see a directional preference or centralization, we tell you to go forth and do those movements that cause good things to happen. That’s it. For someone well trained, we can find a directional preference in most patients. For those that aren’t trained…well…the system may not work, which is a bummer for the patient because it’s not the systems fault.
“The primary findings suggest that (1) classifying patients with lumbar impairments at intake by either McKenzie or pain-pattern classification methods my slightly (around 3%) improve explanatory power in robust risk-adjusted rehabilitations models predicting discharge FS outcomes”
Classifying a patient demonstrates improved results compared to not classifying patients. Although this may be a small improvement over other factors that could predict outcome, it is still better than not classifying. When you go to see a therapist as a patient, you want to know how they are classifying you. As a student, you want to know how sophisticated the clinical instructors classification system is. A therapist that is performing interventions because of tradition is not using a good classification system.
“…therapists with the highest level of McKenzie training (diploma in MDT) achieved significantly better FS (functional) outcomes compared to therapists who did not have a diploma in MDT”
This won’t offend me. I don’t have a Diploma in MDT and personally know many therapists that have earned this distinction. It takes time to complete, a lot of money and time off of work/away from family in order to complete the diploma. If one has access to a therapist with this distinction…please go forth and get assessed.
Look…there are a lot of therapists that say that they “use McKenzie” in their treatment. Be wary of these therapists. McKenzie is not a treatment intervention, but an assessment process. If the therapist doesn’t have the initials denoting passing a certification exam or diploma exam, he/she is not using MDT at even a competent level.
Excerpts taken from:
Werneke MW, Edmond S, Deutscher D, et al. Effect of Adding McKenzie Syndrome, Centralization, Directional Preference, and Psychosocial Classification Variables to a Risk-Adjusted Model Predicting Functional Status Outcomes for Patients with Lumbar Impairments. J Orthop Sports Phys Ther. 2016;46(9):726-741.