Quick Answer: No single sleeping position is universally best, but back sleeping supports spinal alignment most consistently, while side sleeping is ideal for reducing snoring and acid reflux. Stomach sleeping puts the most stress on your neck and lower back and is generally least recommended by chiropractors.
9 min read
Your sleeping position shapes more than just how rested you feel in the morning. It determines how much pressure sits on your spine, whether your airway stays open, and whether you wake up with neck or back pain. The Canadian Chiropractic Association notes that poor spinal positioning during sleep is one of the most overlooked contributors to chronic musculoskeletal pain, affecting an estimated 85% of working Canadians at some point in their lives.
Most people do not consciously choose their position. You fall asleep in whatever feels natural. But understanding what your position does to your body, and how your mattress either helps or works against it, can make a real difference. When customers come into our store on West Street, the first question we ask is not "what firmness do you want?" It's "how do you sleep?" The rest of the conversation flows from there.
The 6 Main Sleeping Positions
Sleep researchers typically identify six primary sleeping positions, though most people shift between a few during the night. Each has a distinct effect on spinal alignment, breathing, and pressure distribution.
Sleeping Positions at a Glance
- Back (supine): Best for spinal alignment; not ideal for snorers or sleep apnea
- Side (lateral): Best for snoring, acid reflux, and pregnancy; needs pressure relief
- Fetal: Most popular worldwide; good for snoring but can strain neck and hips
- Stomach (prone): Hardest on neck and lumbar spine; generally least recommended
- Starfish: Back variation with arms raised; can cause shoulder pressure
- Soldier: Back variation with arms at sides; tends toward snoring
Back Sleeping (Supine)
Back sleeping is generally considered the gold standard for spinal health. When you lie face-up, your weight distributes evenly across the largest surface area of your body. Your spine can maintain its natural S-curve without the lateral bending that side sleeping introduces.
The catch: back sleeping raises the soft palate and allows the tongue to fall toward the throat. This makes it the position most associated with snoring and obstructive sleep apnea. A 2015 study published in the Journal of Clinical Sleep Medicine found that sleep apnea severity was significantly worse in the supine position for roughly 55% of patients.
What the Research Says About Back Sleeping
The Canadian Chiropractic Association recommends back sleeping with a pillow that supports the natural cervical curve, not so thick that it pushes the chin toward the chest, and not so flat that the head falls back. A medium-loft contour pillow positioned under the neck (not under the head) is typically ideal. For those with lower back pain, a pillow under the knees reduces lumbar compression significantly.
Best for: People without sleep apnea or snoring issues, those with lower back pain who use a knee pillow, and anyone recovering from hip or shoulder surgery.
Mattress considerations: Back sleepers generally do best on a medium to medium-firm mattress. Too soft and the hips sink, reversing the lumbar curve. Too firm and the lower back loses contact with the surface, creating a gap that leads to morning stiffness. A medium-firm mattress keeps the hips level while supporting the lumbar region.
Side Sleeping
Side sleeping is the second most common position globally and, for many people, the most practical choice. It opens the airway more than back sleeping, reduces snoring, and is strongly recommended during pregnancy (left side specifically) because it improves circulation to the uterus and reduces pressure on the liver.
The challenge with side sleeping is pressure. Your entire body weight funnels through the contact points, primarily the shoulder and hip on the down side. On a mattress that's too firm, this creates pinch points that can lead to rotator cuff discomfort and hip bursitis-like pressure over time. On a mattress that's too soft, the shoulder and hip sink while the waist isn't supported, creating a lateral bend in the spine.
What We See in Our Brantford Showroom
Side sleepers are by far the most common type we work with. When someone tells us they're waking up with shoulder pain or hip soreness, the most frequent culprit we find is a mattress that's too firm for their body type. Lighter side sleepers, under 130 lbs, often need a genuinely plush surface to allow their shoulder to sink in without bridging. Heavier side sleepers need firmness for support but still need a conforming comfort layer to relieve those pressure points. The right answer is different for every person, which is why we encourage customers to actually lie down for 10–15 minutes on each mattress rather than just pressing with a hand.
Best for: People who snore, those with acid reflux (left-side sleeping reduces symptoms), pregnant women, and most people as a general default.
Mattress considerations: Plush to medium mattresses are generally best for side sleepers. A hybrid mattress with individually wrapped coils and a foam comfort layer provides both pressure relief and support, the coils prevent sinking too deep while the foam cradles the shoulder and hip. Check out our full guide to the best mattresses for side sleepers in Canada.
Fetal Position
The fetal position, curled on your side with knees drawn toward the chest, is the most popular sleeping position worldwide. It's a natural, instinctive posture that most people find deeply comfortable.
Physiologically, it's a variant of side sleeping with additional considerations. The tight curl puts the spine in lateral flexion, which over a full night can contribute to stiffness, particularly in the upper back. People who sleep in a very tight fetal curl may wake with neck tension from having the chin pressed toward the chest. A looser fetal position, with the body only slightly curled, has most of the breathing benefits of side sleeping without the extreme spinal flex.
Research published in Sleep Medicine Reviews notes that the fetal position is particularly common in people with lower back pain, possibly because it opens the vertebral joints and reduces nerve pressure temporarily. However, the same research cautions that the position can worsen pain if maintained too rigidly throughout the night.
Pillow tip: Fetal sleepers benefit from a body pillow placed between the knees. This prevents the top hip from rotating forward and pulling the lumbar spine out of alignment. Our Symbia 50-inch body pillow is designed specifically for this purpose.
Stomach Sleeping (Prone)
Stomach sleeping is the position most consistently flagged by chiropractors and physiotherapists as problematic. When you lie face-down, you must turn your head 90 degrees to one side to breathe. This rotation is held for hours, placing sustained rotational stress on the cervical vertebrae and the muscles along the neck and upper back.
Simultaneously, the lower back arches. The lumbar spine extends instead of maintaining its natural curve, compressing the posterior elements of the vertebrae (facet joints) and potentially aggravating lumbar stenosis or disc issues. The Canadian Physiotherapy Association notes that many chronic neck and lower back complaints in adults who are otherwise healthy are directly traceable to habitual prone sleeping.
Is Stomach Sleeping Ever Recommended?
There is one notable exception: infants should always be placed on their backs to sleep (to reduce SIDS risk), but for adults with obstructive sleep apnea who cannot tolerate CPAP therapy, prone sleeping can reduce apnea events by reducing airway collapse. Outside of specific medical contexts, most healthcare providers recommend transitioning away from stomach sleeping if possible.
If you cannot stop stomach sleeping: Use the thinnest pillow possible for your head, or no pillow at all, to reduce cervical rotation. Place a firm pillow under your pelvis (not your stomach) to reduce lumbar hyperextension. And choose a firm mattress so your hips don't sink and exaggerate the arch.
Transitioning off stomach sleeping takes time. Sleeping on your side with a body pillow in front of you as a barrier is a common physical therapy technique for retraining the habit over several weeks.
Starfish and Soldier Variations
These are both variations of back sleeping with distinct arm positions.
Soldier position: Arms at the sides, body straight, like a person standing at attention. This is one of the better back-sleeping variants because it keeps the arms from creating shoulder pressure. People who sleep in soldier position tend to snore more because the rigid posture keeps the chin slightly raised, narrowing the airway. A slight pillow elevation (two to three inches) can help.
Starfish position: Arms raised above the head or out to the sides, creating a wide splayed posture. The shoulder concern here is real: holding the arms elevated for hours creates sustained tension in the rotator cuff. If you regularly wake with shoulder aching or tingling in the hands, your sleeping position is worth investigating. Bringing the arms down to the sides or onto a pillow at chest height is an easy correction.
Choosing a Mattress for Your Sleep Position
Mattress Firmness by Sleep Position
- Back sleepers: Medium to medium-firm. Lumbar support is priority. Look for a mattress that doesn't let the hips sink more than 1–2 inches.
- Side sleepers: Medium to plush. Shoulder and hip pressure relief is priority. Memory foam or hybrid comfort layers work well.
- Stomach sleepers: Firm to medium-firm. Prevents the hips from sinking and the lumbar from hyperextending. Avoid thick pillow-top surfaces.
- Combination sleepers: Medium is the classic "safe zone." A mattress that's responsive enough to allow position changes without feeling stuck, latex and hybrid mattresses tend to perform best here.
- Fetal position: Same as side sleeper, but body pillow between knees is especially important for hip alignment.
Body weight also matters. A lighter person sleeping on their side needs a softer surface to allow the shoulder to sink in. A heavier person sleeping on their back needs more support depth to prevent total immersion. Our guide to mattress firmness and body type goes deeper on this.
In our experience, the most common mistake is buying a mattress based on what feels comfortable for 30 seconds rather than what actually supports your position for 7–8 hours. A mattress that feels lush and cloud-like when you press your hand on it may be causing problems if you're a stomach sleeper who needs firm support underneath. This is why lying on a mattress for at least 10 minutes in your actual sleep position, not just sitting on the edge, tells you so much more.
Pillow Choice by Sleep Position
The wrong pillow for your position can negate even the best mattress choice. Pillow loft (height) and fill determine whether the cervical spine stays neutral during the night.
Pillow Height Guide by Sleep Position
- Back sleepers: Low to medium loft (3–4 inches). A contour pillow that cradles the neck without pushing the chin forward. Our Somnia posture pillow is designed for this.
- Side sleepers: High loft (4–6 inches depending on shoulder width). The pillow fills the gap between your head and the mattress. Our Somnia 4.5 contour pillow is specifically designed for side sleepers.
- Stomach sleepers: Very low loft or no pillow for the head. A firm pillow under the pelvis instead.
- Combination sleepers: Adjustable-fill pillows work best, you can dial in loft for each position. Our RiseSleep Adjustable Gel Pillow is a good option here.
A dedicated pillow-choosing guide covers all of this in more detail, including materials, fill types, and how to test pillow height at home.
A Simple Home Test for Pillow Height
Stand against a wall. The gap between your neck and the wall is roughly the pillow loft you need. Back sleepers typically measure 2–4 inches; side sleepers with broader shoulders often measure 5–6 inches. This won't be exact, but it rules out pillows that are dramatically wrong for you.
Frequently Asked Questions
What is the healthiest sleeping position?
Back sleeping is generally considered best for spinal alignment because it distributes weight evenly and keeps the spine neutral. However, it's not suitable for everyone, people with sleep apnea, snoring, or acid reflux typically do better on their side. The "healthiest" position depends on your specific health situation, body type, and what your mattress and pillow support.
Is sleeping on your stomach bad for you?
Most chiropractors and physiotherapists advise against it for sustained nightly use. The combination of neck rotation (to breathe) and lumbar hyperextension places prolonged stress on the cervical spine and lower back. If you can't stop, using a very flat pillow for your head and placing a firm pillow under your pelvis helps reduce the impact.
Why do I keep waking up with shoulder pain as a side sleeper?
This usually points to a mattress that's too firm for your body weight. If your shoulder can't sink into the surface, your rotator cuff and the muscles along the shoulder girdle bear the load instead of the mattress. A softer comfort layer, or a mattress topper, typically resolves this. Our guide to side sleeper mattresses covers what to look for.
Can I train myself to sleep in a different position?
Yes, though it takes a few weeks. The most effective technique physical therapists recommend is placing a body pillow behind you (to prevent rolling to your back) or in front of you (to prevent rolling onto your stomach). Some people sew a tennis ball into the back of a sleep shirt as a physical deterrent. Consistency over two to four weeks is usually enough to shift the habit.
Does it matter which side I sleep on?
Yes, in some cases. Left-side sleeping is recommended during pregnancy to improve circulation and reduce pressure on the liver. Left-side sleeping also tends to reduce acid reflux symptoms, since the stomach sits lower than the esophagus in this position. For most people without these concerns, the distinction between left and right side sleeping matters less than whether the mattress properly supports whichever shoulder is down.
Find the Right Mattress for Your Sleep Position
We've been helping Brantford families find the right mattress since 1997. When you come in, we start with your sleep position and work from there, firmness, materials, pillow recommendations, all of it. No pressure, no upselling. Just honest advice.
441 1/2 West Street, Brantford, Ontario
Call 519-770-0001