C CUSHION LAB Extra Support Orthopedic Knee Pillow (Large) review

The Large measures 11 inches long, 8.5 inches wide and 6.5 inches tall (about 28 × 22 × 16.5 cm), and Cushion Lab says it's meant for side sleepers 5′8″ and up, or anyone who wants extra support^[1]. The listing also gives its weight as 1.1 pounds (0.5 kg)^[1]. Cushion Lab's own product page lists 9.5 × 8.5 × 5.5 inches, which matches the Medium's listed length and width^[2,3]. So the Large is the same width as the Medium, with an extra inch of height between your knees and an extra 1.5 inches of length along your legs.

That inch of height is the whole point of this pillow. A knee pillow's job is to hold your top knee level with your top hip. If the knee drops toward the mattress, the top hip slides into adduction, with the thigh angled down and across your body^[4]. Broad hips and thick thighs widen the gap the pillow has to fill, so a pillow that suits an average frame can leave a larger sleeper's top knee hanging low. Most of the other knee pillows we list hold the knees about 5.5 to 6 inches apart. Our knee pillow guide compares them and shows how to check the angle in your own sleeping position.

One naming quirk can make shopping confusing. On Amazon this is the “Extra Support Orthopedic Knee Pillow” in Large. On Cushion Lab's own site it's called the Side Sleeper Knee Pillow and comes in Medium and Large. They're the same product: the Large listing's model number, 3E-MYK3-DG2A, is the Large SKU on Cushion Lab's page^[1,2].

It's one block of dense memory foam cut into a contoured shape, sold as firm support but described by testers as conforming. Cushion Lab calls the foam Hyperfoam and describes it as an extra-dense, CertiPUR-US certified viscoelastic memory foam, designed to support your legs all night without flattening^[2]. The company says all of its memory foams carry CertiPUR-US certification^[5]. The Amazon listing for the Large describes the core as extra-dense, gel-infused memory foam^[1]. Cushion Lab's own page doesn't mention gel, so treat the cooling gel as a listing claim rather than a confirmed spec.

Firmness labels don't agree. Cushion Lab pitches the pillow at people who want firm leg support^[2], while Amazon's product details field calls the Large “medium” and the Medium “soft”^[1,3]. We rate it 7 out of 10, which is medium-firm. The tester description fits that: Good Housekeeping's Grace Wu said the foam “molds to your body without sinking in,” giving a mix of pressure relief and support^[6].

The shape matters as much as the foam. Cushion Lab lists three design features: a contoured, leg-fitting shape, a bolstered middle for rebounding support, and curved edges meant to keep the pillow between your legs^[2]. In practice that's the hourglass profile that many knee pillows share^[6]. Each knee rests in a shallow cradle instead of perching on a flat block, which helps it stay put without a strap.

Testers found it cradles the knees well, and the larger size can sit between the knees or higher up between the thighs. Good Housekeeping Institute tested knee pillows in its lab, including wash tests, and matched 18 consumer testers with pillows to use at home over several weeks. Cushion Lab's pillow won its Best for Pressure Relief award^[6].

All of the testers said it cushioned their knees well. One said the contoured shape cradled the knees and kept them in place. Another said it easily held a gap between her knees. Wu added that, compared with similar styles in the test, the larger size sat nicely between the knees or thighs for a range of body types^[6].

Cushion Lab describes it as fitting between the thighs^[1], and Mayo Clinic's side-sleeping advice for back pain is to draw your legs up slightly toward your chest and put a pillow between your legs^[7]. Try both spots for a few nights. Between the knees, the full 6.5 inches separates the bony points. Higher up, the contour sits against softer thigh tissue.

What it doesn't do is support your lower leg. At 11 inches long, it stops well short of your shins, so your top foot can still drop toward the bed. For outer hip pain, Alison Grimaldi and Angela Fearon suggest pillows between the knees and the shins^[4]. If your top ankle sags, add a folded pillow lower down, or look at a full-length body pillow instead.

Turning over takes practice. With no strap, the pillow only comes with you if your knees carry it. Good Housekeeping notes a learning curve with most knee pillows if you move around at night: you have to actively work to keep one in place between your legs^[6]. The contoured edges help, but expect to fish it out from the sheets now and then during the first week.

Pick by the width of your hips and thighs more than your height, and buy where returns are easy. Cushion Lab draws the line at 5′8″^[1]. Good Housekeeping's testers didn't find that rule reliable: one tester under 5′8″ preferred the Large, while others found even the standard size a little too wide^[6].

That isn't surprising. Height is only a stand-in for frame size. Two people of the same height can have very different hip widths, and a pillow that levels one person's top leg can push another person's knee above their hip. Lean toward the Large if standard knee pillows feel flat by morning, if your top knee still angles down with one in place, or if you have broad hips. Lean toward the Medium if you're slim or petite, or if the Large props your top knee higher than your hip.

You can measure before you order. Lie on your side with your knees bent and your top thigh level, and have someone measure the gap between your inner knees. If it's closer to 6.5 inches (16.5 cm) than 5.5 inches (14 cm), start with the Large. If it's smaller, start with the Medium.

Returns depend on where you buy. Bought directly from Cushion Lab, you can return it within 30 days of purchase for a full refund, as long as it's in like-new condition and in its original packaging. You pay the return shipping, and the original shipping fee isn't refunded^[8]. The Large Amazon listing advertises a satisfaction guarantee with a full refund^[1]; check the return window shown at checkout before you open it.

It suits the everyday problems a knee pillow targets, with one caveat after hip surgery. The evidence behind knee pillows in general is covered in our knee pillow guide. Here's how this pillow fits each case.

• Outer hip pain. Keeping the top knee up reduces adduction of the top hip, which is the aim for gluteal tendinopathy and “bursitis” type pain^[4]. A dense pillow helps here because it keeps its height. A pillow that compresses lets the knee sag back down by morning.
• Low back pain and sciatica. NHS specialists at the Royal Orthopaedic Hospital suggest a small, firm cushion between the knees when you lie on your side^[9]. This pillow is both.
• Bony or sore knees. Stacked knees press bone onto bone. Pressure-care guides recommend pillows between the knees and ankles to keep bony points from touching^[10], and 6.5 inches of foam keeps them well apart. If osteoarthritis makes your knees tender, though, this dense foam may feel harder than you want.
• Pregnancy. The NHS suggests a pillow between your legs for extra support in bed if you have pelvic girdle pain^[11], and the listing names pregnancy among its uses^[1]. It won't support your bump or back, though. Our body and pregnancy pillow guide covers pillows that do.
• After a hip replacement. Follow your surgical team. After a posterior-approach replacement, Hospital for Special Surgery tells patients lying on the non-operated side to keep at least two firm pillows between the legs so they never cross^[12]. A single knee pillow isn't a substitute for that setup or for an abduction pillow, so ask before you switch.

Expect some warmth, because it's solid memory foam held between two warm legs, and no tester we found measured its temperature. Sleep Foundation notes that most knee pillows are memory foam, which tends to trap heat, and that breathable covers are the usual fix^[13]. Cushion Lab's cover is hypoallergenic, 100% recycled polyester with what the company calls Air-Layer technology to move air away^[2]. Good Housekeeping's testers scored temperature as part of their ratings, but the write-up doesn't comment on heat for this pillow^[6]. If you already run hot at night, the Contour Legacy has ventilation holes in the foam.

Cleaning is simple. The cover comes off and is machine washable. Cushion Lab says to air dry it or tumble dry on low heat, and that the memory foam core itself isn't washable^[2]. Because the core can't go in the machine, wash the cover often if you sweat at night.

Cushion Lab says its extra-dense foam is designed not to flatten^[2], but the warranty is short at one year. Cushion Lab covers defects in materials and workmanship under normal use for one year from purchase, for the original buyer^[5,1]. A defect warranty isn't a promise that the foam won't soften with use.

Sleep Foundation says knee pillows can last anywhere from one year to several years^[13]. Since this pillow's job is to hold one specific gap, judge it by function, not looks. Every few months, lie on your side with it in place and check whether your top knee still sits level with your hip. When the knee starts to drop, the foam has compressed and the pillow has done its time.

Choose the Cushion Lab Large for size, the ComfiLife for value, and the Contour Legacy if heat bothers you.

• ComfiLife Orthopedic Knee Pillow: Good Housekeeping named it Best Value in the same test that gave Cushion Lab its pressure relief award^[6]. It's our best-value knee pillow: firm, simple and cheaper.
• Contour Legacy Leg & Knee: the hourglass design its maker calls the original, with ventilation holes in the foam. A better fit if heat matters more to you than extra height.
• 5 STARS UNITED: our softest knee pick. It may be kinder to sore, arthritic knees, but it's less likely to hold a wide gap for a large frame.
• Coop Adjustable Body Pillow: if you want your shins, arms and chest supported too, a body pillow does what no knee pillow can.

Buy the Large if you're tall or broad-hipped, standard knee pillows feel flat by morning, and you want a dense, contoured spacer with a pressure relief award from a hands-on test. Skip it if you're petite (get the Medium), you sleep hot and want ventilation, your top foot drops and you need shin support, or you just want the cheapest spacer that works.