Thomas test is used to assess tight hip flexors. What constitutes a positive Thomas test?

• A. The knee remains extended and the lumbar spine remains neutral.
• B. The involved hip flexes or the lumbar spine flexes.
• C. The contralateral leg remains in extension.
• D. Pain in the knee occurs with hip flexion.

Answer: (B)

The main idea here is that the Thomas test checks for tight hip flexors, especially the iliopsoas. When you perform the test, a positive result is seen if the leg being tested does not stay relaxed in neutral and instead shows hip flexion, or if the pelvis causes the lower back to flex as you bring the knee toward the chest. In other words, tight hip flexors pull the thigh into flexion and can force the lumbar spine to flex as a compensatory change. If the involved leg lies flat on the table with the hip and knee fully extended and the lumbar spine remains neutral, the test is not positive. Pain in the knee isn’t the defining sign of hip flexor tightness, and the position of the contralateral leg isn’t the key diagnostic cue.