Which reflex test indicates lumbosacral nerve root irritation when positive?

Lasegue's sign, also known as the straight leg raise test, is used to assess lumbosacral nerve root irritation, particularly involving the lumbar and sacral nerve roots (L4 to S1). When this test is positive, it typically indicates the presence of nerve root compression, often due to conditions like a herniated disc. A positive Lasegue's sign occurs when raising a straight leg elicits pain along the distribution of the sciatic nerve, suggesting irritation or compression of the lumbosacral nerve roots.

The other tests mentioned assess different aspects of neurological function. The patellar reflex evaluates the integrity of the L2 to L4 spinal nerves, specifically the femoral nerve, and is more related to knee extension. The Achilles reflex tests the S1 to S2 nerve roots via the tibial nerve and does not specifically indicate lumbosacral irritation. The Babinski reflex is an upper motor neuron sign that is not directly linked to lumbosacral nerve irritation but rather indicates neurological function of descending motor pathways. Understanding the specificity of each reflex test helps in clinical assessments of nerve root conditions.