March 1, 2017

The Ultimate Girl Push Up: McKenzie Method.

Author: Maggie Henjum

 

As 62% of patients with low back pain experience pain at 12 months, we continue to spin our wheels on a track valiant effort to improve heterogeneity and treatment patterns to hone in our skills and treatment effects.Robin McKenzie was either an entrepreneur or an expert observer as he discovered that a certain patient centralized with repetitive motions.Conceptually, much speculation on why this would work has been discussed. When I took McKenzie course work, their primary hypothesis was that dependent on the location of the disc bulge – repetitive motion would move this viscous fluid to a non-aggravating position.For example, a posteriolateral disc bulge would respond well with extension as this moves the disc anteriorly taking the pressure of of the nerve root. As with most concepts, it not that simple. Chemical and mechanical pain are both effected by movement as nociceptors in both situations are activated and are influenced by motion.  We are only able to diagnose about 15% of patients with low back pain with definite pathology, which leaves 85% of patients defying a diagnosis. In recent years it has increasingly become clear that much of the pain with acute radiculopathy is chemical, not nerve root compressive in nature.12 Meaning – not everyone is a disc. Simplicity seems to never be the case with low back pain and peripheral symptoms are included in that camp.

The cerebral side of me thinks if we can identify who gets radiating pain, or localize the mechanisms of its prevalence we would prevent and impact it at a faster rate. Unfortunately, these modifiable factors are not necessarily in the physical therapy camp. They include: smoking, obesity, occupational factors and health status along with non modifiable factors of gender, age and social class.3 This may be part in reason why therapists chose McKenzie methods less frequently for the older patient.Again with unfortunate report, even the operational definition of what leg pain is are always under debate which even made this weeks literature search challenging. Although I am a fan of semantics, it does seem to limit our research – seemingly more prevalent in this topic. A healthy dose of debate is stimulating, but a universally used term would be beneficial as apposed to: directional preference, centralizing, McKenzie, extension based exercise, etc.  Therefore, as most disagree with pathology of distal symptoms, at least the directional preference category provides a safe place for everyone to come together and dig for better outcomes. Rules of agreement in this classification are patients who centralize their symptoms with repetitive movement. These criteria have previously been found to have acceptable degree of intertester reliability (Kappa value 0.64) and construct validity (likelihood ratio 6.9) using a positive discography as reference standard.5

A general systematic flow of evaluation starts with a good subjective examination that closely evaluates possibility of a directional preference during daily tasks, or even self selected behavior. After a clear picture of a patients SINSS is identified, this drives subsequent evaluation. For example, if a patient is severe, highly irritable, and unstable, but drives a clear picture of what is relieving – possibly extension, I would not take the time to evaluate AROM in loaded/standing positioning. Here, it would be more advantageous for patient outcomes to calm down the system and provide positive feedback with a possible relieving or centralizing motion. Conversely, a patient who has more chronicity to their symptoms, low irritability, and low severity, may need or allow more thoroughness to a standing AROM exam, and repetitive motions in numerous positions. Centralization is a commonly observed physical examination finding with a systematic review identifying the phenomenon as occurring in 65% of patients with LBP.Unfortunately, not everyone fits the mold that we would hope. Directional preference is demonstrated in about 60% of patients, and only 41% of these centralize – indicating these can be mutually exclusive.6 Especially for the chronic, and older patient, finding a directional preference can prove challenging. Hopeful finding of a directional preference lends a better functional status and less pain compared to those who do not centralize or have directional preference.6

 

Although this has demonstrated good anecdotal success for the directional preference patient, what does the literature say?

If it is used early:

Mchado et al:Here they found that when McKenzie is added to the currently recommended first-line care of acute low back pain, it does not produce appreciable additional short-term improvements in pain, disability, function or global perceived effect. Although, McKenzie method does reduce health care utilization and decreases re-occurrence rates.

Compared to manipulation:

Peterson et al:Patients were either administered manipulation or directional preference exercises (McKenzie method). This was one of my favorite studies as it is clinically useful as we know manipulation provides good outcomes for low back pain. Although, not all patients expect or want this treatment as it is a high velocity product – thus it is beneficial for us to see that in this study about half of the patients reported a reduction in the mean disability about 50% by the end of treatment and that these were maintained for 1 year. Other points of interest here was that most actually favored the McKezie method and a NNT was 8.

Compared to stabilization:

Hosseinifar et al:11 In patients with chronic non-specific low back pain were compared to see if extension based exercises increased the thickness of the transverses abdomens (TrA) and the lumbar multifudus (LM) after 18 sessions. Although I did enjoy this article, they administered 6 exercises per patient in the McKenzie group which really isn’t matching McKenzie methodology. Therefore, this article is really assessing if end range stretching adds any benefit of TrA or LM. Findings were that stabilization exercises are more effective than McKenzie exercises in improving the intensity of pain and function score and in increasing the thickness of the transverse abdominis muscle.

Systematic Review:

Surkitt et al:9 This systematic review was an excellent read – they found “low evidence from one trial (imprecision, indirectness due to a co-intervention) that directional preference is more effective than a stabilizing/strengthening exercise program at improving intermediate-term function however there is no significant difference in intermediate-term pain and long-term function outcomes.” One high quality trial found that directional preference involving McKenzie treatment matching a participant’s directional preference was “significantly more effective than multidirectional mid range lumbar exercises, stretches and advice for each short-term pain, function and work participation outcome.”

Does it affect prognosis?

Long et al:10 Leg pain, work status, depression, pain location, chronicity, and treatment assignment were significant predictors of outcome in univariate analysis. Subjects with DP/centralization who received matched treatment had a 7.8 times greater likelihood of a good outcome. Matching patients to their DP is a stronger predictor of outcome than a range of other biopsychosocial factors.

It is of my personal opinion that directional preference should have a strong place in therapist’s tool box. This doesn’t need to replace manual techniques, or stabilization of the spine, but as a positive input to the nervous system, mobility exercise and patient empowerment I think it can be invaluable. For the right patient, explaining centralization and administering a self control technique to track their outcomes and change there pain is high up on my list of options for management of low back pain. Criticism of literature is the want to think unilaterally that this can’t be utilized in conjunction with other treatment options – it can. Also, that it is appropriate for everyone – it is not. Therefore, as we narrow our scope in on who benefits most from this method. In the meantime, it should at least be a thought for every therapist managing low back pain – can I change their pain with one or two exercises that promote movement and control?

 

Original post: February 2, 2014

 

References:

  1. Surkitt L, Ford J, Hahne A, Pizzari T, McMeeken J. Efficacy of Directional Preference Management for Low Back Pain: A Systematic Review. Physical Therapy. 2012; 2-44.
  2. Dr. Bob Boyles.  Directional Preference Basics.  Lecture performed by Evidence in Motion.  February 1, 2014.
  3. Cook CE, Taylor J, Wright A, Milosavljevic S, Goode A, Whitford M. Risk Factors for First Time Incidence Sciatica: A Systematic Review. Physiother Res Int. 2013 Dec 11.
  4. Peterson T, Larsen K, Nordsteen J, Olsen S, Fournier , Jacobsen S. The McKenzie Method Compared With Manipulation When Used Adjunctive to Information and Advice in Low Back Pain Patients Presenting With Centralization or Peripheralization. Spine. 2011; 36: 1999-2010.
  5. Peterson T, Larsen K, Nordsteen J, Olsen S, Fournier , Jacobsen S. The McKenzie Method Compared With Manipulation When Used Adjunctive to Information and Advice in Low Back Pain Patients Presenting With Centralization or Peripheralization. Spine. 2011; 36: 1999-2010.
  6. Werneke M, Hart D, Cutrone G, Oliver D, McGill M, Weinberg J, Grigsby D, Oswald W, Ward J. Association Between Directional Preference and Centralization in Patients with Low Back Pain. JOSPT. 2011; 41: 22-32.
  7. Greenberger HB, Beissner K, Jewell DV. Patient age is related to the types of physical therapy interventions provided for chronic low back pain: an observational study. J Orthop Sports Phys Ther. 2012 Nov;42(11):902-11. doi: 10.2519/jospt.2012.4147.
  8. Machado L, Maher C, Herbert R, Clare H, McAuley J. The Effectiveness of McKenzie Method in Addition to First-Line Care for Acute Low Back Pain: A RCT. BMC Medicine. 2010; 8:10.
  9. Surkitt L, Ford J, Hahne A, Pizzari T, McMeeken J. Efficacy of Directional Preference Management for Low Back Pain: A Systematic Review. Physical Therapy. 2012; 2-44.
  10. Long A, May S, Fung T. The comparative prognostic value of directional preference and centralization: a useful tool for front-line clinicians. J Man Manip Ther. 2008;16(4):248-54.
  11. Hosseinifar M, Aknari M, Sarrafzadeh J. The Effects of Stabilization and Mckenzie Exercises on Transverse Abdominis and Mulfidus Muscle Thickness, Pain, and Disability: A RCT in NS-CLBP. J Phys Ther Sci. 2013 Dec;25(12):1541-5. doi: 10.1589/jpts.25.1541. Epub 2014 Jan 8
  12. 12. Murphy D, Hurwitz E, Clary R. A Non-Surgical Approach to the Management of Lumbar Spinal Stenosis: A Prospective Observational Cohort Study. BMC Musculoskeletal Disorder. 2006; 7: 16
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