Ankylosing Spondylitis vs. Mechanical Low Back Pain: Recognizing Axial Inflammation and Lumbar Stiffness through the Schober Test

Low back pain is one of the most common complaints in clinical practice, and its etiology can be varied. Among the most frequent causes are mechanical low back pain and ankylosing spondylitis, a form of axial inflammation. Recognizing the difference between these two conditions is crucial for appropriate and effective treatment.
Diving Deeper into Differentiation
Mechanical low back pain is usually the result of injuries or strains in the muscles, ligaments, or intervertebral discs. This type of pain generally improves with rest and can be treated with physical therapy and analgesics. On the other hand, ankylosing spondylitis is a chronic inflammatory disease that primarily affects the spine and sacroiliac joints. It is characterized by morning lumbar stiffness that improves with exercise and not with rest, and it may be associated with other extra-articular manifestations such as uveitis or psoriasis.
Ankylosing spondylitis is frequently associated with the HLA-B27 antigen, and its diagnosis can be confirmed through imaging techniques such as magnetic resonance imaging, which reveals inflammation in the sacroiliac joints. The Schober test is a useful clinical tool for assessing lumbar mobility in these patients.
In contrast, mechanical low back pain does not present these inflammatory markers and is usually more localized. Clinical evaluation and patient history are essential for differentiating between these conditions, as treatment and prognosis vary significantly.
Conclusions
The distinction between ankylosing spondylitis and mechanical low back pain is essential for the proper management of the patient. While mechanical pain can be treated with conservative measures, ankylosing spondylitis requires a more aggressive approach, including the use of non-steroidal anti-inflammatory drugs and, in some cases, biological agents. Early identification of axial inflammation can prevent complications and improve the patient's quality of life.
Referencias
- [1] Recognizing Axial Spondyloarthritis: A Guide for Primary Care
- [2] Differential diagnosis between mechanical and inflammatory lower back pain, therapy options
- [3] Sacroiliac Joint Injury
Created 6/1/2025