The Thomas stretch works on the muscles at the front of the hip (hip flexors, mainly iliopsoas) while you lie on your back. You lie at the very end of a firm bed, hug one knee toward your chest and let the other leg hang down over the edge. Hugging one knee keeps your lower back and pelvis still, so the hanging thigh can drop and stretch the front of that hip. Physios use a similar position to check hip flexor length, known as the Thomas test.

How to do the thomas stretch

Sit on the end of a firm, stable bed or treatment table. Lie back with a pillow under your head, so your bottom is right at the edge and both legs hang down over the end.
Lift the leg you are not stretching and hug that knee toward your chest, with both hands holding just below the knee.
Draw the knee in only until your lower back rests flat on the bed. Pulling harder than that adds nothing.
Let the other leg relax and hang over the end, knee soft and only a little bent, as in the video. You should feel a stretch at the front of that hip as the thigh drops.
Hold still and breathe normally. In the video each hold lasts about 10 seconds.
Slowly lower the hugged leg back down so both legs hang again. Rest, then repeat.

What you should feel

A stretch at the front of the hip on the hanging leg, sometimes reaching into the top of the thigh. The hugged leg should feel supported, and your lower back should feel relaxed on the bed.

Common mistakes

Lying too far up the bed, so the hanging thigh has nowhere to drop.
Letting go of the knee and allowing the lower back to arch off the bed.
Pulling the hugged knee in so hard that the hip or knee pinches.
Letting the hanging leg roll out to the side instead of keeping the knee pointing up toward the ceiling.

How often

Many programs hold this position for around 20 to 30 seconds and repeat it 2 to 3 times, once or twice a day. The shorter holds in the video are a fair place to start if the stretch feels strong. Your physio will adjust this.

Stop and check with your physio if

A sharp or pinching pain at the front of the hip or in the groin, on either side.
Your lower back hurts or pinches while you are in the stretch.
Numbness, tingling or burning spreads down the front of the hanging thigh.

From the clinic

The voice guide calls the hugged leg your unaffected leg, so the stretch lands on the side that is tight or sore. Use a bed or table that does not tip or slide, and check where the edge is before you lie back. When you finish, bring both knees up, roll onto your side and push yourself up with your arms rather than sitting straight up from your back.

Feel it more in the front of the thigh than in the hip? Try the standing quad stretch. The hip flexor stretch in a split stance needs no bed at all.

If you have had a hip replacement, get the go-ahead from your surgeon or physio before you try the Thomas stretch. Hugging one knee in bends that hip well past a right angle while the other thigh drops below the line of your body, and many surgeons ask you to avoid that for the first months after some operations. If you are pregnant and beyond the first trimester, check with your physio before doing stretches that have you lying on your back.

Written and checked by the PocketPhysio editorial team. Last updated 2026-09-26.

This page is general education, not a diagnosis or a personal treatment plan. If you have pain, an injury or a health condition, see a physiotherapist or doctor before starting new exercises.

Thomas stretch