The best posture to sleep in is a posture that aligns your body correctly. Perfect sleeping posture is where your muscles are supported so they don’t pull on your joints, and your joints are relaxed but supported in a neutral position.
Best sleep posture for back sleepers
For back sleepers, the best posture to sleep in is NOT flat on your back. Sleeping flat on your back with your legs straight strains the joints in your lower back. Instead, to sleep in the best sleeping posture, back sleepers should sleep with their feet resting on a knee wedge pillow.
When you sleep with your legs elevated on a knee wedge pillow, it not only improves circulation throughout your body, but also aligns your spine. With the weight of your legs supported, your back lies flat against the mattress instead of arching like it does when your legs are straight. When your back is lying flat, the joints in your spine are in a neutral and restful position.
Best posture to sleep in for side sleepers
For side sleepers, the best sleeping posture is with your lower back and hips fully supported. To do this, you use a side sleeper wedge to support your lower back, and a leg separator pillow to support your hips, lower back, knees, and ankles.
A side sleeper wedge is a small wedge that fits in the small of your waist. Part of the reason that people wake up with back pain when sleeping on their side is because when you sleep without the curve of your waist unsupported, your spine curves down towards the bed. A side sleeper wedge will keep your spine straight. A supported spine is a happy spine.
Have you ever thought about the fact that when you sleep on your side, there is a slope from the top of your hip down to your knee and down to your ankle? This slope means the muscles in your lower back and hips are being pulled. This can lead to muscle pain, joint pain, and can exacerbate conditions like hip bursitis and IT Band syndrome.
To align the lower body, side sleepers should use a supportive leg separator pillow. This is different than “putting a pillow in between your knees.” A leg separator pillow should be supportive enough to hold your top leg as close to parallel to the bed as possible. It should also be long enough that it can run from your groin to your feet.
For stomach sleepers
Unfortunately, there is no good sleep posture for stomach sleepers. Sleeping on your stomach puts strain on your neck, shoulders, and lower back. It's best to transition from sleeping on your stomach to sleeping on your side.
The best posture to sleep in is either sleeping on your back or your side in a way that aligns your muscles and joints so they are fully at rest. When your muscles and joints are at rest, you can rest!
-Bryan Blare, Doctor of Physical Therapy