Knee Pillow for Side Sleepers: How to Use One for Hip and Lower-Back Comfort
Updated November 2026 · By the Beauty Pillow team
Quick answer: When you sleep on your side, your top leg tends to slide forward and down, twisting the pelvis and pulling the lower back out of line. A pillow between the knees keeps the legs stacked, so the hips, pelvis and spine stay in a more neutral position. Mayo Clinic recommends exactly this for side sleepers with back pain: bend your knees slightly toward your chest and place a pillow between your legs.
Why a pillow between the knees helps
Without support, the top knee slides forward and drops toward the mattress. The top hip rotates forward with it, and the lower back twists slightly. Over a full night, that can leave the hips, knees or lower back feeling stiff. A knee pillow fills the gap between the knees so the top leg rests level with the hip.
How to position a knee pillow
- Lie on your side and bend your knees slightly, drawing them a little toward your chest.
- Place the pillow between your knees so your top knee sits level with your hip.
- Check your head pillow: it should fill the space between your ear and shoulder so your neck stays in line with your spine.
- If you change sides during the night, take the pillow with you; a contoured knee pillow is easier to keep in place than a regular pillow.
Back or stomach sleeper?
| Position | Where the pillow goes | Why |
|---|---|---|
| Side | Between the knees | Keeps the legs, hips and spine aligned |
| Back | Under the knees | Mayo Clinic notes this may relax the back muscles and help maintain the natural curve of the lower back |
| Stomach | Under the hips and lower stomach | Mayo Clinic describes stomach sleeping as hard on the back and suggests this if you can't sleep any other way |
What to look for in a knee pillow
- A contoured shape that cups the thighs and knees, so it stays in place when you move
- Supportive foam that doesn't flatten under the weight of the leg overnight
- Enough height to keep your top knee level with your hip
- A removable, washable cover
Our Knee & Leg Support Pillow
The Knee & Leg Support Pillow is a contoured memory foam pillow for side sleepers (between the knees) and back sleepers (under the knees).
- Size: 19.5 × 25.5 × 13 cm (7.7 × 10 × 5.1 in)
- Material: memory foam with a Skin+ cover
- Shape: side support walls, upper thigh support, a knee separation zone and lower leg support
If you also wake up with creases on your face, the Beauty Pillow + Knee Support Pillow Set combines it with our contoured anti-wrinkle pillow for back and side sleepers.
Frequently asked questions
Should the pillow go between the knees or the ankles?
Between the knees for most people. If your lower legs also drop, a longer pillow or a body pillow can support the whole leg.
Is it OK to use a knee pillow every night?
Yes. Many side sleepers use one every night as part of their normal setup.
Can a knee pillow help with sciatica or hip pain?
Many people find side sleeping with a knee pillow more comfortable, but it is not a treatment. If you have ongoing or severe pain, talk to a doctor or physical therapist.
Is a knee pillow useful during pregnancy?
Side sleeping with a pillow between the knees is a common choice during pregnancy. Ask your healthcare provider what support is right for you.
Memory foam or a regular pillow between the knees?
A regular pillow works, but it tends to flatten and slip out during the night. A contoured memory foam pillow keeps its height and stays in place.
Sources
- Mayo Clinic. Sleeping positions that reduce back pain.
This article is for general information and is not medical advice.
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