McKenzie Method (MDT) for Acute & Chronic Knee Pain

Knee pain is the most common lower limb problem in the general population. The prevalence increases as we get older from 20% in individuals 20-30 years old to 40% in individuals over the age of 60.

The McKenzie method is an alternative system of classifying and treating spinal disorders. Robin McKenzie expanded this approach to include classification and treatment of the extremities. The system is based on the symptomatic and mechanical responses of patients to various repeated movements or static load forces. This mechanical evaluation allows therapists to classify an injury into a broad category as opposed to the conventional method’s tissue-specific category. All classifications within this system have been found to have different response characteristic patterns. The four classifications in the McKenzie method are know as: derangement syndrome, dysfunction syndrome, postural syndrome and other.

Healthy joints will articulate through a pain-free normal and functional range of motion. With most articulating joints there is a potential for development of loose bodies (particles, bone spurs, articular tissue, etc.) that can displace and block the normal movement of the joint. This is classified as an internal derangement of the joint and will typically presents with painful and limited movement into one or more directions. Certain repeated movements that progressively reduce the pain will also dislodge and reduce the obstruction allowing return to normal pain-free movement. Typical presentation of a derangement is: a) variable pain pattern (not consistent), b) limited range of motion (obstruction), c) locking and/or clicking in joint. Treatment of a knee derangement requires evaluation to determine directional preference, the direction your joint needs to move in order to reduce the blockage. If flexion based activities (squatting, stairs, sitting) increase pain and you’re limited in knee extension or straightening then you’re derangement will most likely reduce with repeated knee extension. This is the most common derangement found in the knee however, in some cases the knee requires repeated flexion (knee bending) in order to reduce. A McKenzie certified therapist can evaluate and determine directional preference and the amount of force (active, passive, or active with overpressure) required.

Dysfunction syndrome can be divided into two sub-categories, articular dysfunction and contractile dysfunction. A dysfunction is caused by a mechanical deformation of structurally impaired soft tissue (tendon, ligament, muscle, etc.). Previous trauma or degenerative changes can cause contraction, scarring, adherence, and/or adaptive shortening of the tissue. The pain from this condition is felt when this structurally impaired tissue is loaded (i.e. weight-bearing). Typical presentation of a dysfunction is: a) not constant but is consistent; b) pain at end-range of movement; c) limited range of motion (may or may not be present). The pain will be produced only as the affected structure is loaded and abolished when the load is removed. Treatment of a dysfunction requires remodeling of the impaired tissue. This may involve scar tissue massage, stretching, progressive loading, and strengthening. Unlike the treatment of a derangement where you may see rapid relief in symptoms; the dysfunction can take anywhere from weeks to months to completely remodel.

Postural syndrome arises from sustained loading of soft tissues. This is uncommon but presents with pain that is only produced by prolonged static loading of normal tissue. The individual will present with intermittent pain and normal range of motion. Treatment consists of patient education and modification of activity. This is most commonly seen in adolescents.

Failure to classify into a mechanical syndrome (derangement, dysfunction, postural) will result in classification as “other” or non-mechanical in origin. Individuals who typically fall under this category are post-surgical.

If you or someone you know is suffering from acute, chronic, or post-operative knee pain please get in touch with your general practitioner or a local physical therapist. For more information on the McKenzie Method: www.mckenzieinstituteusa.org.

Article written by Dr. Kaitlyn Hamel, Physical Therapist at Seacoast Spine & Sports Injuries Clinic in Portsmouth, Hampton and Alton, New Hampshire.