The way you position yourself when lying down can either relieve lower back pain or make it significantly worse. The two most protective positions are on your back with a pillow under your knees, or on your side with a pillow between your knees. Both keep your spine in a neutral alignment that takes pressure off the muscles and discs in your lower back. Just as important as your position, though, is how you get into and out of bed, and how long you stay there.
Best Positions for Lying Down
If you sleep on your back, place a pillow under your knees. This relaxes the muscles along your lower spine and preserves its natural curve, preventing your pelvis from tilting forward and pulling on your back. If you still feel a gap between your lower back and the mattress, tuck a small rolled towel under your waist for extra support.
If you prefer your side, draw your knees up slightly and place a firm pillow between them. This keeps your hips, pelvis, and spine aligned so your top leg doesn’t pull your spine into a twist. The pillow should be thick enough that your knees stay roughly hip-width apart. A thin pillow that compresses flat won’t do much.
A loose fetal position, where you lie on your side with your knees gently pulled toward your chest, can help if you have a herniated disc or spinal stenosis. Curling up opens the spaces between your vertebrae, which reduces pressure on compressed nerves. The key word is “loose.” Pulling your knees too tightly toward your chest can strain your hips and round your spine excessively.
Positions to Avoid or Modify
Stomach sleeping is the hardest position on your lower back. It forces your lumbar spine into extension, compressing the joints and muscles along the back of your spine. It also requires you to turn your head to one side for hours, which strains your neck and upper back. If you genuinely cannot fall asleep any other way, placing a flat pillow under your pelvis can reduce some of the arch in your lower back. Using a very flat head pillow, or no pillow at all, also helps keep your spine closer to neutral.
Adjustments for Sciatica
Sciatica adds a layer of complexity because the pain radiates down your leg, and certain positions can increase tension on the sciatic nerve. Back sleeping with a pillow under your knees works well here too, since it prevents your lower back from arching and pressing on the nerve root. Side sleeping with a pillow between your knees aligns your hips and takes pressure off the pelvis, which is where the sciatic nerve passes through.
If your sciatica is caused by spinal stenosis (a narrowing of the spinal canal), sleeping in a slightly rounded or reclined position tends to feel best. You can achieve this by using a large wedge pillow under your head and upper back, sleeping in a recliner or adjustable bed with the head elevated, or curling into a fetal position. All of these open up the spinal canal and reduce compression on the nerves.
How to Get In and Out of Bed
The moment most people aggravate their back isn’t while lying still. It’s the twist-and-push motion of getting into or out of bed. The log roll technique eliminates that twist entirely.
To get into bed, sit on the edge with your back straight. Without twisting your torso, begin lowering yourself onto your side, using your arms to control the descent. As your upper body lowers, let your legs rise onto the mattress at the same time, keeping them in line with your trunk. The goal is to move your body as one unit, like a log rolling, rather than dropping your shoulders first and swinging your legs up after.
To get out, reverse the process. Roll onto the side closest to the edge of the bed. Use your arms to push your upper body upright while simultaneously lowering your legs to the floor, keeping your trunk straight the entire time. Push yourself to standing with your hands on the mattress. This feels awkward the first few times, but it prevents the spinal twisting and flexion that can send a sharp bolt of pain through your lower back.
How Long You Should Stay in Bed
Lying down feels like the right thing to do when your back hurts, but extended bed rest actually slows recovery. Harvard Health recommends limiting time in bed to a few hours at a stretch, and no more than a day or two total. Clinical trials consistently show that returning to normal activities early, with short rest breaks as needed, leads to better outcomes than staying home in bed for days.
Prolonged lying down weakens the muscles that support your spine, stiffens your joints, and can make pain worse over time. Think of rest as a tool you use in small doses, not a treatment plan. Getting up to walk, even briefly, keeps blood flowing to injured tissues and prevents the deconditioning that makes your next flare-up more likely.
Your Mattress Matters
The surface you’re lying on plays a real role in whether your position helps or hurts. The old advice to sleep on the firmest mattress possible is outdated. Current recommendations from sleep and spine experts favor a medium-firm mattress, which provides enough support to keep your spine aligned while also cushioning your joints and pressure points. A mattress that’s too firm creates gaps under your lower back and pushes against your hips and shoulders. One that’s too soft lets your body sink unevenly, pulling your spine out of alignment.
If buying a new mattress isn’t realistic right now, you can experiment with what you have. A thin plywood board between your mattress and box spring adds firmness to a sagging bed. A mattress topper can soften one that feels like concrete. The test is simple: when you lie in your preferred position, your spine should feel like it’s in the same alignment as when you’re standing with good posture.