Which test is typically used for diagnosing lumbar radiculopathy?

Lasegue's sign, also known as the straight leg raise test, is commonly used to diagnose lumbar radiculopathy. This test involves raising the patient's straight leg while they are lying down. If this maneuver causes pain that radiates down the leg, it indicates irritation or compression of the lumbar nerve roots, which is characteristic of lumbar radiculopathy. The mechanism behind this test is that by elevating the straight leg, tension is applied to the sciatic nerve and the roots from where it originates, allowing the examiner to assess for nerve root involvement.

In contrast, Spurling's test is primarily utilized to assess cervical radiculopathy, as it involves extending and laterally bending the cervical spine to see if that reproduces radicular symptoms. Choi's test is less commonly referenced in standard clinical practice and is not a routine test for lumbar radiculopathy specifically. Kehr's sign indicates referred pain from splenic irritation or other intra-abdominal pathology and is not related to lumbar nerve root issues. Thus, Lasegue's sign is the most appropriate and specific test for diagnosing lumbar radiculopathy among the choices provided.