Mechanical Diagnosis And Therapy: A Systems Approach To Musculoskeletal Injuries

Systems thinking in health care forces the clinician to venture far from the shore in terms of their training and their beliefs. But in order to have a truly comprehensive system of health care, it will require clinicians to push the envelope of their thinking and let go of their belief systems. They will need to embrace assessment processes that allow the clinician to understand the behavior of the system as a whole, and a patient-centered treatment approach that emphasizes self care strategies.

Mechanical Diagnosis And Therapy (MDT) is a true systems approach to disorders of the musculoskeletal system. It is the next great revolution in musculoskeletal care, yet it also currently creates discomfort amongst many clinicians. Why? It forces clinicians to let go of the patho-anatomical model of care they have held near and dear for decades.

Every so often in science, a chance occurrence leads a clinician or researcher to an epiphany, which then pushes their thinking down a new road. Resistance is met from many groups, primarily because it challenges the commonly-held beliefs of the day. But the clinician pushes on, and the concept is advanced and eventually supported by the research. Robin McKenzie, a physiotherapist from New Zealand, was one such clinician.

With some astute clinical observations, McKenzie established certain consistent symptomatic and mechanical responses to repeated end range movements and sustained postures. He then used these responses to group patients into three primary diagnostic categories – posture, dysfunction, and derangement. He was able to describe mutually exclusive subgroups of patients based on principles of mechanical loading and pain production that have been well-established in cellular physiology. Diagnostic classification would then lead to an appropriate treatment plan which would include self treatment strategies. With an understanding of the behavior of the mechanical system, a clinician could effectively propose patient-centered self treatment strategies based on sound tissue loading principles.

The McKenzie Method has now received positive support in the research literature. Over the years, the McKenzie Method has also been mimicked, if not copied outright, by many other clinicians and groups. As they say, imitation is the greatest form of flattery.

McKenzie himself tried to define his own method based on the perceived hypothetical patho-anatomy involved. Having developed a broad approach to understanding the symptomatic and mechanical behaviors of the system (in true "systems thinking" style), even McKenzie had a desire to put it into the context of a patho-anatomical model! But what sets MDT apart - and what gives it its greatest power - is the fact that a patho-anatomical context is not necessary to describe a condition or its treatment.

As long as we have McKenzie's operational definitions, and we understand the dynamics of tissue loading, does it really matter what is causing the problem in a patho-anatomical context? A mechanical assessment identifies any specific red flags and precautions that would prevent the application of mechanical loading strategies. If the patient knows what "better" is in terms of function, mechanics and symptoms, then they can self-treat safely and effectively. Isn’t that the primary goal of musculoskeletal care?

McKenzie was, in effect, one of the first systems thinkers in medicine. As a result, MDT focuses on the behavior of the system - the "big picture" - instead of the micromanagement of patho-anatomical minutiae, impairments and mal-alignments that does not provide any greater insight nor value-added benefit for the patient’s ability to actually improve their outcome.

Photo credits: Wikipedia