Thomas Test
- Target muscle
- —
- Equipment
- Body weight
- Body part
- Stretching
- Type
- Stretching
The Thomas Test is a classic hip flexor flexibility assessment performed at the edge of a bench or table. You hug one knee to your chest while letting the opposite leg hang free, revealing tightness in the hip flexors — particularly the iliopsoas and rectus femoris. It doubles as a passive stretch when held, making it useful for both evaluation and targeted flexibility work.
How to do the Thomas Test
- 1Sit on the edge of a firm bench or table so your hips are at the very end.
- 2Lie back and bring both knees toward your chest, holding them with your hands.
- 3Keep your lower back flat against the bench throughout the test.
- 4Release one leg and let it lower toward the floor while continuing to hug the opposite knee firmly to your chest.
- 5Allow the hanging leg to relax completely — do not actively push it down.
- 6Observe or feel how far the thigh drops: ideally it reaches parallel to the floor or below.
- 7Hold the position for 20–30 seconds if using it as a stretch.
- 8Return the lowered leg to your chest, then switch sides and repeat.
Form tips
- Press your lower back firmly into the bench before releasing the leg — any arch reduces the accuracy of the assessment and the effectiveness of the stretch.
- Keep the hugged knee pulled all the way to your chest; letting it drift forward allows the pelvis to tilt and masks hip flexor tightness.
- Let gravity do the work on the hanging leg — actively pushing it down is not the same as passive flexibility.
- If your knee on the hanging leg bends past 90 degrees, that indicates rectus femoris tightness separate from iliopsoas tightness.
- Perform on a stable surface with enough room for the leg to hang freely without touching the floor.
Common mistakes
- Arching the lower back off the bench: this tilts the pelvis and shortens the hip flexors artificially, making the test look normal when tightness is present.
- Not hugging the test knee close enough: a loosely held knee allows the pelvis to rotate, giving a false reading and reducing the stretch effect.
- Actively lowering the hanging leg: using muscle effort to push the leg down tests strength rather than passive flexibility.
- Sitting too far from the edge: if the hip is not at the very end of the bench, the thigh cannot hang freely past neutral and the hip flexors are never fully challenged.
- Rushing the hold: holding for only a few seconds does not allow the hip flexors to relax into the stretch; aim for at least 20 seconds per side.
Frequently asked questions
What does the Thomas Test measure?
It assesses passive flexibility and potential tightness in the hip flexor muscles, primarily the iliopsoas and rectus femoris. If the hanging thigh cannot reach parallel to the floor, hip flexor tightness is indicated. Excessive knee bend in the hanging leg (beyond 90 degrees) specifically points to rectus femoris tightness.
Can I use the Thomas Test as a stretch, not just an assessment?
Yes. Holding the position for 20–30 seconds with the lower back flat and the opposite knee hugged to the chest creates a passive stretch on the hip flexors of the hanging leg. Repeating this daily can gradually improve flexibility over time.
How do I know if I have tight hip flexors from this test?
If the thigh of the hanging leg sits above parallel to the floor when you are fully relaxed and your lower back is flat, that indicates hip flexor tightness. The greater the angle above parallel, the more restricted the range of motion.
Do I need any equipment to perform the Thomas Test?
You need a firm bench, table, or elevated surface where your hips can rest at the very edge and your legs can hang freely. A standard weight bench or massage table works well. No other equipment is required.
How often should I do the Thomas Test stretch?
For flexibility improvement, perform it daily or at least five times per week, holding each side for 20–30 seconds. Reassess your range of motion every two to four weeks to track progress.
