When a patient's pain symptoms can be made better or worse by adopting various, differentiated active positions, it is said that a patient has a directional preference of movement for treatment. The identification of a directional preference through mechanical means is the hallmark of the McKenzie Method (which is often referred to Mechanical Diagnosis and Therapy or MDT).
The patient's beneficial 'directional preference' also is the direction of movement that causes pain symptoms to move more centrally (toward the mid-back or neck), where they are generally better tolerated than if the pain were to remain in the legs, hips, or low back.
Correct assessment or mechanical diagnosis is the key to prescribing effective back pain exercises. Without the aid of a good assessment, there are no McKenzie exercises; there are just exercises, the efficacy of which is questionable.
The McKenzie assessment consists of taking a patient history and performing a physical exam. Both are used to gauge the degree of impairment as well as identify any red flags that might be contrary to exercise-based treatment (e.g. fracture, tumor, infections, or systemic inflammatory disease).
During the McKenzie physical examination, patients are taken through provocative loading strategies (movements) that help classify the patient and determine the best treatment approach. The movements are intended to either increase or decrease symptoms. For example, patients may be asked to perform single and/or repeated flexion or extension movements forward and backward.
These movements are done to 'end range' - the point at which the patient's range is limited for any reason - and are done in both standing and lying positions. Lateral flexion movements may also be performed. These loading strategies may abolish symptoms, identify symptoms that occur only in certain positions, or cause symptoms to become either more central or peripheral. Once a directional preference is identified, the patient is classified and various McKenzie exercises prescribed for therapy.