Thomas test

The Thomas test is a physical examination test, named after the Welsh orthopaedic surgeon, Hugh Owen Thomas (1834–1891), to rule out hip flexion contracture (fixed partial flexion of the hip) and psoas syndrome (injury to the psoas muscle).

[1] If the iliopsoas muscle is shortened, or a contracture is present, the lower extremity on the involved side will be unable to fully extend at the hip.

[2] Sometimes, with a very flexible patient, the Thomas test will be normal despite a psoas dysfunction being present.

However, in the patient with a normal hip joint, a positive test is a good indicator of psoas hypertonicity.

[3] Psoas syndrome is often associated with runners, dancers, and gymnasts who complain of hip "stiffness" and reported "snapping" feeling when flexing at the waist.

Illustration of the Thomas test. From Hugh Thomas Owen's "Diseases of the hip, knee, and ankle joints: with their deformities, treated by a new and efficient method", 1875.