Common Misconceptions of the McKenzie Method® of Mechanical Diagnosis and Therapy® – MDT

There are many misconceptions associated with MDT, several of which are listed below:

  • Just a series of exercises
  • Only about Derangement
  • Only extension exercises are used
  • Only about the intervertebral disc
  • Only about repeated end range movements
  • Ignores biopsychosocial issues
  • Does not utilise manual therapy
  • Only about spinal conditions

Let us address each of these issues point by point to more accurately portray what MDT is:

MDT is not just a series of exercises: Although exercises are important, MDT is an assessment process and a problem solving paradigm. The clinician takes clues from the history about the effects of specific loading strategies on symptoms. During the history, the clinician begins to formulate a differential diagnosis. First, is it a problem with a mechanical influence, a medical influence, a biopsychosocial influence or any combination of the above?

Secondly, if mechanical, which of the syndromes is likely the diagnosis: Derangement, Dysfunction, Posture or Other. The physical examination, which includes a series of loading strategies confirms or refutes the postulated diagnosis.

imageMDT is not only about Derangement: Although very common, Derangement syndrome is not the only syndrome in MDT. The other two syndromes - Dysfunction and Postural Syndrome are important clinical entities. The fourth classification is ‘Other’ which consists of a number of sub groups of pathologies that can be recognised by MDT clinicians and managed appropriately. Sub groups of ‘Other’ include stenosis, chronic pain, sacro-iliac joint, mechanically unresponsive radiculopathy, trauma / recovering trauma and post-surgery.

MDT is not just extension: Although extension is a common treatment recommendation, all planes of movement are considered in both assessment and treatment. The direction of exercise utilised in treatment is dependent on the symptomatic and mechanical response to repeated movements or sustained positions during the assessment process.

MDT is not just about the intervertebral disc: Whilst the disc model is a useful way of explaining the Derangement syndrome in the spine, the actual source of most low back pain is not known. It needs to be stressed that MDT is not reliant on a patho-anatomical diagnosis but is based around on a sound classification system based on symptomatic and mechanical response to repeated movements, and this in itself guides the clinician to the required management strategy.

MDT is not just about repeated end range movements: Static positioning and mid-range movements are all part of the spectrum of force progressions and force alternatives.

MDT does not ignore bio-psychosocial influences: In fact, with its emphasis on education and patient empowerment, MDT is a very strong bio-psychosocial system of clinical management. MDT clinicians are trained to recognise psychosocial factors including fear avoidance behaviour and passive coping strategies.

MDT does not exclude manual therapy: Although we take a “hands off” approach first, mobilisation and manipulation are all part of the continuum of force progressions. The MDT focus is primarily on education and self-directed treatments in order to reduce dependency on the clinician and to empower the patient to control their symptoms. Where this is not successful the use of hands-on techniques such as mobilisation forms part of the force progression. However, the use of hands-on techniques is only used to enable the patient to return to self-treatment.                                         

MDT is not just about the spine: The concepts of assessment and classification can also be applied successfully to the extremities where it is becoming increasingly supported in the literature.

As a brief summary, MDT is a classification system. It seeks to differentiate between mechanical and non-mechanical sources of pain and functional limitation. Symptomatic and mechanical changes are assessed using repeated end range movements and sustained positions.