Primary care physicians frequently see patients with low back pain (LBP). To minimise excessive lumbar flexion, societal attempts to reduce LBP have resulted in more upright work settings. Mechanical Diagnosis and Therapy has proven to be reliable among well-trained MDT doctors (Deutscher D, et al. 2014; Kilpikoski S, et al. 2002) and can decrease patient visits while increasing clinical and functional results (Deutscher D, et al. 2014; Long A, et al. 2004; May S, and Aina A, 2012). Patients in the direction-specific or directional preference (DP) exercise group show centralization, cessation, or decrease in symptoms or gain in range of motion in response to specified repeated motions during evaluation (Long A, et al. 2004). Anterior derangement is a subset of derangement syndrome that has a DP for flexion (McKenzie and May, 2003).

Flexion loading has been found to cause posterior displacement of the nucleus polposus and may thus play a role in posterolateral annulus distortion or failure (Edmonston et al., 2000; Fennell et al., 1996; Moore et al., 1996). Flexion, on the other hand, may result in centralization. Although it is less prevalent, a tiny number of LBP sufferers centralise with flexion (Donelson et al., 1991). As a result, in the case of a lumbar disc lesion, this surgery should result in changes in clinical and/or mechanical presentation (McKenzie and May, 2003).

Characteristics of the anterior derangement (McKenzie and May, 2003; Takasaki H, AND May S. 2018):

• Patients frequently complain of lower back, anterior thigh, or inguinal pain with no neurological indications or symptoms.

• Slouching frequently lowers pain after sitting; however, standing and walking gradually increase pain.
• History may be hazy.
• Patients may have considerable flexion loss, locking them in lordosis, but impairment is minimal.
• Lumbar flexion is frequently limited by stiffness rather than discomfort.
• There is usually no loss of lumbar extension.
• Accentuated lordosis.
• In lumbar flexion, one-sided deviation may be noticed.
• The response to repeated extension may be ambiguous, rather than causing symptoms to intensify or the lordosis to lock in extension.
• Sustained end-range extension is likely to create pain and a blockage of lumbar flexion.
• Mechanical lumbar flexion loading must eliminate, decrease, or centralise symptoms and may increase flexion range.

Takasaki H. and May S. (2018) observed that a patient with LBP diagnosed with anterior derangement syndrome displayed rapid aggravation with sustained but not repeated mechanical loading in the direction of lumbar extension and rapid recovery with repeated lumbar flexion. This finding is backed by a case study conducted in 2022 by Greer B. et al., who used sustained lumbar extension as a test to assist in identifying flexion directional preference as well as directional preference. Finally, symptomatic reactions give support for the loading approach used. If the symptoms are asymmetrical or unilateral, particularly if there is flexion deviation, flexion operations with a lateral component may be required.

Several studies have found that flexion is the least common directional preference and extension is the most common. In a study of centralization responses to sagittal plane movements (Donelson et al. 1991), 40% preferred extension and 7% chose flexion. Long et al. (2004) found that 83% of patients with a verified abnormality preferred extension, 7% preferred flexion, and 10% preferred lateral. Hefford C. (2008) discovered that 70% of participants preferred extension, 6% preferred flexion, and 24% preferred lateral.

Finally, I’d like to highlight the following results of spinal conditions that necessitate flexion:

1. Anterior Derangement.
2. Flexion Dysfunction.
3. Adherent nerve root (ANR).
4. Nerve Root Entrapment.
5. Symptomatic Stenosis.
6. Some cases of Symptomatic Spondylolisthesis.
7. Recovery of Function – Posterior Derangement.

References:

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2. Donelson R, Grant W, Kamps C, Medcalf R. Pain response to sagittal end range spinal motion. A prospective, randomised, multicentred trial. Spine 1991;16:S206–12.
3. Edmonston SJ, Song S, Bricknell RV, et al. MRI evaluation of lumbar spine flexion and extension in asymptomatic individuals. Manual Therapy 2000;5:158–64.
4. Fennell AJ, Jones AP, Hukins DWL. Migration of the nucleus pulposus within the intervertebral disc during flexion and extension of the spine. Spine 1996;21:2753–7.
5. Greer B, Tranquillo J, Maccio J, Flexion Directional Preference in a Patient with Low Back Pain, Utilizing Mechanical Diagnosis and Therapy: A Case Report , JOSPT Cases, 2(1):44–49, 2022.
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10. McKenzie R, May S 2003 The Lumbar Spine: mechanical Diagnosis and Therapy (2nd). Waikenae: Spinal Publications New Zealand Ltd.
11. Moore RJ, Vernon-Roberts B, Fraser RD, Osti OL, Schembri M. The origin and fate of herniated lumbar intervertebral disc tissue. Spine 1996;21(18):2149–55.
12. Takasaki H, May S, Concerns related to the accurate identification of anterior derangement syndrome in mechanical diagnosis and therapy for low back pain: A case report. Physiother Theory Pract., 36(4):533‐541., 2020.