Extension Bias and Directional Preferences

Have you ever noticed how some positions make your back feel better, while others make it feel worse? For certain common back problems such as herniated disc, facet arthritis, sacroiliac joint pain, and others, pain can be associated with specific positions. Your physical therapist or personal trainer can use this information to help you manage symptoms at home, at work, and while exercising.

A therapist assisting a man with stretching exercises

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Directional Preferences

These directional preferences are part of a movement-based approach to categorizing low back pain that allows your therapist to watch how you stand, sit, walk and move, and to listen to what you have to say about your pain. 

The approach is called the non-pathoanatomical system of classification. The McKenzie system, widely in use by physiotherapists around the world, is perhaps the best example of a non-pathoanatomical classification system. 

The Pathoanatomical vs Non-Pathoanatomical Approach

There's also a pathoanatomical approach that is more focused on your physical examination and diagnostic tests. The use of both approaches together is important in the diagnostic process and in formulating a therapeutic plan.

In their clinical practice guidelines for low back pain, for example, the American Physical Therapy Association reports that in 20% to 76% of people with no sciatica who underwent imaging tests, herniated discs could be found. And, in 32% of patients who had no symptoms at all, either disc degeneration, bulging or herniation, facet joint hypertrophy, or spinal nerve root compression was detected. The authors add that it's possible for people to get low back pain while their x-rays or CT scans remain unchanged. 

If Your Back Favors Extension

If your symptoms decrease or go away altogether when you arch your back, your back condition likely has an extension bias. Your doctor or therapist may note this during your evaluation, but you might notice the trend on your own when you are doing things—like picking things up or putting your shoes on.

Flexion bias is another type of bias that can occur with back pain, With flexion bias, you would feel more discomfort when arching your back, and improvement of your pain when flexing your spine forward.

In general, disc problems and posterior longitudinal ligament injuries have extension biases. 

Things you can do to be more comfortable if you have extension bias include:

  • Lying in the prone position, which arches (extends) the back
  • Minimize or eliminate activities in which the spine has to flex, such as rounding your back when you pick things (or people) up from the floor or a chair
  • Ask your healthcare provider or physical therapist about extension bias and how you might exercise or position your spine to manage your back pain and other symptoms
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  • Delitto, A., PT, PhD., et. al. "Low Back Pain. Clinical Practice Guidelines Linked to the International Classification of Functioning, Disability, and Health from the Orthopaedic Section of the American Physical Therapy Association." J Orthop Sports Phys Ther. 2012.

  • Dunsford A, Kumar S, Clarke S. "Integrating Evidence Into Practice: Use of Mckenzie-Based Treatment for Mechanical Low Back Pain." J Multidiscip Healthc. 2011;4:393-402. DOI: 10.2147/JMDH.S24733

  • Nachemson, A. "Scientific Diagnosis or Unproved Label for Back Pain Patients. Lumbar Segmental Instability." Szpalski M, Gunzburg R, Pope MH eds. Philadelphia: Lippincott William & Wilkins, 297-301.

  • Kinser, C., Colby, L.A., Therapeutic Exercise: Foundations and Techniques. 4th Edition. F.A. Davis Company. Philadelphia, PA. 2002.

By Anne Asher, CPT
Anne Asher, ACE-certified personal trainer, health coach, and orthopedic exercise specialist, is a back and neck pain expert.