Most people think “tight hip flexors” just means one muscle, but there are a few different players involved: iliacus, psoas, TFL, rectus fem, and even sartorius to a degree. The Thomas test is one of the cleanest ways to see which one is actually limiting your range. • If the leg drops when you abduct it, the TFL is the one stopping the length. • If the knee cannot get close to 100 degrees flexion, the rectus fem is hanging on. • If neither of those change anything, you are looking at iliacus an