Lower Back Not Touching the Floor? Why That Gap Is Normal

A lower back not touching the floor is normal when you lie on your back, and it is one of the first things people notice in a lesson. Your lower spine has a gentle inward curve. So it arches away from the floor a little while your pelvis and ribs rest down. That small space is part of how a spine is built, and it does not mean anything is out of place.

I hear this question often in Feldenkrais Method® lessons. Someone lies down, begins to scan the back of the body, and finds a space where they expected contact. Then they ask, a little worried, whether they should push it down. The short reply is no. The longer reply is more interesting, and it starts with the shape of the spine.

Why your lower back is not touching the floor

Seen from the side, the spine is not a straight rod. It has a series of soft curves. The neck curves inward, the upper back curves outward, and the lower back curves inward again. Doctors call this lower curve the lumbar lordosis. "Lumbar" means the lower back. "Lordosis" simply means a curve that bends toward the front of the body.

When you lie on your back, the floor meets the parts of you that stand out the most. Those are usually the back of the head, the shoulder blades, the back of the ribs, the pelvis and the heels. The lower back sits between the ribs and the pelvis, and its inward curve carries it slightly up and away. So a space appears under the waist. Many people can slide a whole hand into it. Some can fit only a few fingers, and some feel almost no space at all.

These curves have a purpose. They help the spine share the load of your weight and soften the small jolts of walking. A spine with its natural curves is a spine doing its everyday work.

What changes the gap under your lower back

The gap under your lower back when lying down varies a lot from person to person, and even from day to day. A few things shape it.

The depth of your curve. Some spines curve more and some curve less. Both are ordinary variations, in the same way that feet come with higher or lower arches.

The shape of your buttocks and back. Fuller buttocks lift the pelvis higher off the floor, so the space under the waist looks bigger. A rounder upper back can do something similar from the other end.

How your pelvis and hip fronts rest. When your legs lie long and straight, the muscles at the front of the hips are lengthened. They can gently draw the pelvis forward, so it tips and the arch grows. If you have read about how anterior pelvic tilt relates to lower back pain, this is the same tipping, seen while you lie down.

Bent knees or straight legs. This is the change most people notice first. Bend your knees and stand your feet on the floor, and the pelvis can roll back a little. The waist then sinks nearer the floor, and the space often shrinks. Lengthen your legs again, and it usually returns.

The surface under you. A soft mattress lets the pelvis sink and fills the space. A firm floor shows it more clearly.

How settled you are. The muscles along the back often hold more firmly at the start of a lesson. As you rest and move gently, many people feel the back spread and grow heavier. The space can soften over twenty minutes, without any pushing at all.

Should you press your lower back flat to the floor

Pressing the lower back flat is not a goal. You can do it by tightening the belly and tucking the pelvis, and some exercise classes ask for it on purpose. As a way of resting, though, it asks the muscles to work hard to hold a shape your spine does not need. Most people tire of it quickly. The effort can leave the back feeling more held than before.

A more useful question is how your back meets the floor. Where is the contact clear? Where is it light? Does one side of the waist feel nearer the floor than the other? Questions like these turn a worry into information. In Feldenkrais, curiosity tends to change more than force does, because the nervous system responds to what feels safe and easy.

It also helps to keep pain in its place. According to the World Health Organization, roughly nine in ten cases of low back pain are nonspecific, meaning no single clear cause can be found (WHO, 2023). The space under your waist is not pain, and it is not a diagnosis. Even when a back does ache, the curve on its own is rarely the whole story. Our Feldypedia guide to chronic lower back pain looks at that wider picture.

A gentle way to explore how your back meets the floor

Here is a short exploration you can try on a carpet, a mat or a firm bed. Move slowly, and keep every movement small enough to stay easy.

Settle onto your back with both knees bent and the soles of your feet flat, about pelvis width apart. Let your arms rest by your sides. Take a few breaths and sense the back of your body: the head, the shoulder blades, the pelvis. Then bring your attention to your waist. Is there a space under it? Roughly how big does it seem? You might slide a hand under to check, then take the hand away again.

Now begin a very small rocking of the pelvis. Press lightly through your feet, and let the pelvis roll so your tailbone lifts a little and your waist comes nearer the floor. Then let it roll the other way, so the tailbone sinks and the waist lifts slightly. Go back and forth a few times, slowly, like a rocking chair with a very shallow curve. Notice how far up your spine the movement travels. Then stop and rest.

After the rest, sense your waist again. Has the space changed? Does the back feel wider, heavier, or about the same? Then slowly lengthen one leg along the floor, and then the other. Notice what happens under your waist as the legs grow long. Compare it with how it felt at the start.

There is no result to aim for. Some people find the space shrinks. Others find it stays the same size and simply feels less held. Either way, you have learned something about your own back. For a slower way into this, our gentle notes on how to relax your back build on the same idea, and the supine pelvic tilt takes the rocking further. If lying flat feels uncomfortable, our guide on how to lie down with lower back pain suggests supported positions.

Alongside clinical care and other methods

This kind of noticing sits alongside clinical care and never replaces it. A doctor or physiotherapist can assess your back, and gentle awareness work can go along with whatever they suggest.

Please ask a clinician if lying on your back is painful, if back pain wakes you at night, or if you feel numbness, tingling or weakness in a leg. A sudden change in the shape of your back, or pain after a fall, is also worth checking. If you lose control of your bladder or bowel, or the groin area goes numb, get urgent care.

Other movement methods look at the lower back curve from their own angles. Pilates often trains the deep belly muscles, and some of its exercises use a flattened back on purpose. Yoga works through held shapes and steady breathing. The Alexander Technique explores how you organize yourself during daily actions such as sitting and standing. Each works through a different route, and many people enjoy combining them. The Feldenkrais approach leans on slow, small movement and attention, so you discover new options rather than hold one fixed shape.

If you would like guided lessons that begin right here, lying down and sensing the floor, Feldy offers short audio lessons you can follow with your eyes closed. You can also see how the program supports people with lower back pain.

Common Questions about a lower back not touching the floor (FAQ)

Is it normal for my lower back not to touch the floor when I lie down?

Yes. The lower spine curves gently inward, so it usually lifts a little off the floor while the pelvis and ribs rest down. A small space under the waist is expected. Its size varies from person to person, and on its own it is not a sign of a problem.

Should I try to flatten my lower back against the floor?

There is no need. Holding the back flat takes steady muscle effort, and the spine does not need that shape to rest. It is more useful to notice where your back meets the floor and where it lifts. Gentle movement and rest often let the back settle by itself.

Why does my lower back touch the floor when I bend my knees?

With the knees bent and the feet standing, the pelvis can roll back a little. That brings the waist nearer the floor. With straight legs, the fronts of the hips stay long and can tip the pelvis forward, which deepens the arch. Both positions are normal.

How long until the gap under my lower back changes?

It differs for everyone. Many people feel the back grow heavier or wider after one slow lesson. Others notice a change over a few weeks of regular, gentle practice. The aim is a back that feels easy, whatever size the gap turns out to be.

What is the best way to lie down if my lower back does not touch the floor?

Many people feel most comfortable with the knees bent and the feet standing, or with a pillow or rolled towel under the knees. A folded towel under the waist can also feel supportive. Choose whatever lets you breathe and rest without effort.

Can a big gap under my lower back cause pain?

A deeper curve is a common variation, and on its own it does not mean pain will follow. Most low back pain has no single clear cause. If you do have pain, look at the wider picture, such as how you move through your day, and ask a clinician if you are unsure.

When should I ask a clinician about how my back rests on the floor?

Ask a clinician if lying on your back is painful, if pain wakes you at night, or if you notice numbness, tingling or weakness in a leg. A sudden change in the shape of your back is also worth checking. Seek urgent care for any loss of bladder or bowel control.