Tests & Diagnosis
In order to test for sacroiliac joint tenderness – the most common and easily identifiable symptom of ankylosing spondylitis – your physician will conduct one or more physical examinations to reveal tenderness in the sacroiliac joint area:
- Wall Test: Assesses range of motion in the neck.
- Chest Expansion Test: Measures chest expansion capability.
- Pelvic Compression Test: Assesses joint pain in the pelvis area.
- Lower Back (Schober’s) Test: Measures flexibility of the spine.
- FABER test: Assesses pain in the hip and sacroiliac joint
- Leg Drop (Gaenslen’s) Test: Assesses level of pain in the sacroiliac joint.
- Occiput to Wall Test: Measures the distance from the back of the head to the wall.
These tests can also be used to assess progression of AS after an initial diagnosis is made, allowing your physician to track changes in range of motion and flexibility, stiffness and pain in the spinal area over time.
X-rays can also reveal changes to joints and bones indicative of early onset AS, as can magnetic resonance imaging (MRI) tests.
AS is diagnosed clinically, based on specific signs and symptoms that only a doctor can properly assess; you should not attempt these tests on your own. Other (differential) diagnoses must be ruled out due to their similarity with some symptoms of ankylosing spondylitis:
- Other spondyloarthropathies (seronegative inflammatory diseases)
- Spinal injury
- Cancerous tumour