The Schober test is a simple, non-invasive physical examination utilized by healthcare professionals to assess the flexibility of the lower back, also known as the lumbar spine. This quick procedure helps to evaluate how well a person can bend forward, providing a straightforward measure of spinal mobility.
Purpose of the Schober Test
The primary purpose of the Schober test is to serve as a screening tool for detecting reduced flexion in the lumbar spine. Healthcare providers often use this test when inflammatory conditions affecting the spine are suspected. Such conditions include ankylosing spondylitis and other spondyloarthropathies, which are types of inflammatory arthritis that cause stiffness and pain in the spine. The Schober test helps a doctor understand if a patient’s spinal movement is limited, which can then guide further diagnostic steps. It also aids in monitoring the progression of these conditions and evaluating the effectiveness of treatments over time.
The Schober Test Procedure
The Schober test begins with the patient standing upright with their feet about 30 cm apart. A clinician first locates the spinous process of the fifth lumbar vertebra (L5) on the patient’s lower back and marks it with a horizontal line. A second mark is then made 10 centimeters directly above this initial line.
The patient is then instructed to bend forward as far as possible, as if trying to touch their toes, while keeping their knees straight. Once the patient reaches their maximum forward bend, the clinician measures the new distance between the two marked points. This difference between the standing and bent measurements indicates the degree of lumbar flexion.
A common variation, the Modified Schober Test, uses different anatomical landmarks for marking. For this version, the clinician identifies the posterior superior iliac spines (PSIS), which are bony prominences often felt as dimples on the lower back. A horizontal line is drawn at the center point between these two PSIS marks. A second mark is then placed 10 centimeters above this central line, and a third mark is placed 5 centimeters below it, creating a total initial distance of 15 centimeters. The patient then bends forward, and the distance between the top and bottom marks is remeasured.
Interpreting Test Results
The measurements obtained from the Schober test provide information about lumbar spine flexibility. A normal result shows an increase in the distance between the two marked points of 5 centimeters or more when the patient bends forward. This increase suggests a healthy range of motion in the lower back. Conversely, a restricted result, indicated by an increase of less than 5 centimeters, suggests a limitation in lumbar flexion. While a restricted result can be a sign of conditions like ankylosing spondylitis or other issues causing lower back stiffness, the Schober test is a screening tool and not a definitive diagnosis on its own. An abnormal finding prompts a physician to order further investigations, such as imaging studies like X-rays or MRI scans, and blood tests, to confirm any underlying medical condition.