Tight hips This test helps you figure out why. The Thomas test is a simple clinical screen used to tell whether limited hip motion is coming from the hip flexors or the quadriceps. These two are often grouped together but they behave very differently and need different approaches. As a physical therapist this is a test I use often when someone reports tight hips anterior hip discomfort or stiffness that does not improve with stretching. To perform it lie on your back near the edge of a table pul