When you bend forward, your hips should fold, not your lower back

If you threw out your back putting on socks or washing your face

Key points in 30 seconds

1. In a study that measured the pressure inside the disc directly, bending forward while standing was about 2 times the pressure of standing, and sitting back comfortably was a little lower than standing.
2. With the same 20 kg box, lifting with a rounded back was about 4.6 times, and lifting with bent knees and the box held close to the body was about 2.2 times, a difference of more than double.
3. The real star of bending forward is the hip joint. When the pelvis is stiff, the lower back moves to do its share too.
4. There's one move to learn: bending forward by pushing your hips back. Apply it to lifting, putting on socks, washing your face, the first hour of the morning and sneezing.
5. This article is about herniated discs. Spinal stenosis is a condition that feels better when you bend forward, so the movements to be careful with are different.

What we often hear

• "It wasn't anything heavy. I threw my back out picking up a tissue."
• "Washing my face in the morning is the scariest part."
• "I heard sitting is the worst thing for your back."
• "Do I have to live without ever bending forward?"

Think back to the moment you threw out your back.

Some people do it lifting something heavy, but surprisingly often it happens at moments like these. Putting on socks. Washing your face. Picking up a tissue from the floor. Lifting your child in the morning. All small, ordinary movements, but in that moment you feel something give way in your lower back, and your leg starts to pull.

Here we explain why those ordinary movements are a big deal for a disc, and how to change the same movements. The key fits in one sentence. When you bend forward, your lower back shouldn't fold. Your hips should.

How much is the disc squeezed in each position?

There's a study that actually measured it. A tiny pressure sensor was placed inside a lumbar disc of a healthy adult, and the pressure inside the disc was measured through a day of different positions and movements. Taking standing as 1, here's how it looks.

Position or movement	Compared with standing
Lying flat on your back	About 1/5
Sitting back comfortably	A little lower
Sitting and bending forward as far as possible	About 1.6 times
Standing and bending forward	About 2 times
Lifting a 20 kg box with bent knees, held close to the body	About 2.2 times
Lifting the same box with bent knees	About 3.4 times
Lifting the same box with a rounded back	About 4.6 times

Two things stand out in this table.

First, what presses hard on the disc is the moment you round your back to bend forward, more than sitting itself. People often say sitting is the worst thing for your back, but in this measurement, sitting back comfortably was lower than standing. Whether sitting or standing, pressure goes up when you curl your back to bend forward.

Second, even with the same weight, pressure differs by more than double depending on how you lift. It comes down to whether you lift with a rounded back, or bend your knees and hold the load close to your body.

To be honest, this study measured one person, so the numbers themselves are for reference only. But the direction, that pressure rises the more you bend forward, matches earlier studies and is reliable.

So do I have to live without bending forward?

There's no need for that. You just need to change how you bend.

In the exam room, we explain it like this. We say "bending your back," but the real star of bending your body forward is the hip joint. Normally, the pelvis folds forward, the upper body comes down, and the lower back keeps its shape on top. The lumbar spine is built more for holding steady than for moving a lot, so the more it moves, the less stable it becomes.

But after years of sitting for long periods or working in a squat, the area around the pelvis stiffens and doesn't fold well. Since the body still has to bend, it curls the lower back instead of using the pelvis that won't move. Every time, the lower back does the pelvis's share of the work too.

When that adds up to dozens of times a day over several years, the pressure pushing the disc backward is repeated over and over. The moment you threw out your back putting on socks was the last of countless movements your lower back had been doing in the pelvis's place for years.

How do I practice bending from the hips?

Stand with your back to a wall, one step away from it. Bend your knees slightly and try pushing your hips back until they touch the wall.

As you do this, your lower back shouldn't curl; your back and lower back should stay like one flat board while only your upper body tilts forward. This is practice for feeling in your body the difference between bending from the lower back and bending from the hips.

It feels awkward at first, and the backs of your thighs will pull. That's the feeling of your pelvis folding.

How should I change things in daily life?

First, when lifting things. Bend your knees, push your hips back and lower yourself close to the object, then hold it tight against your body and stand up using your legs. With the same box, pressure was twice as high when lifted with a rounded back as when held close to the body. If you can't reduce the weight, reduce the distance.

Second, when putting on socks and washing your face. At the sink, put one hand on the counter and bend your knees slightly. Put on socks and shoes sitting down, or with one foot up on a chair or step. While you have disc pain, just avoiding curling your back to reach down to your feet while standing can make your mornings different.

Third, the first hour of the morning. In the same study, the disc absorbed water overnight, so its pressure was higher in the morning. Be especially careful about lifting heavy things or bending deeply right after you get up. When lifting your child, too, sit down first and then stand up with them.

Fourth, when sitting. The problem is less sitting for a long time than sitting hunched forward. Lean against the backrest, and get up and change position once an hour. Changing position often is better for your back than straining to hold a perfect posture.

Fifth, when you cough or sneeze. Disc pressure shoots up for a moment. If you're standing, put a hand on your knee or a wall, and do it without curling your back.

Is changing the movement enough?

Behind the movement are two foundations. In the exam room, we say, "To stay pain-free, you need two things: strength and flexibility."

• Flexibility: For the pelvis to fold, the backs of the thighs and the area around the hips need to be supple.
• Strength: For the lower back to keep its shape, the abs and glutes need to support it.

Some people have strength but lack flexibility, so the lower back moves in its place. Others are flexible but lack the strength to support it. The prescription depends on which one is missing.

There's one thing we must add. This article is about herniated discs. Spinal stenosis is a condition that actually feels better when you bend forward, so with a different name come different movements to be careful with (the spinal stenosis stretching article). The right order is to first know the name of your leg numbness, and how to tell them apart is summarized in My legs are numb. Is it a herniated disc or spinal stenosis?.

If your bladder or bowel habits have changed, the area where a bike saddle touches has gone numb, or your ankles or toes are getting weaker and weaker, this isn't something to fix by correcting movement. You need a surgical evaluation right away, and if you come to us, we'll tell you the same thing and refer you right away.

How we work

First, we look at what moves and what's stiff. We have you do the forward bend yourself to see whether your lower back or your pelvis folds, and check the alignment of your pelvis and spine with the X-body posture analysis. We examine leg strength, sensation and warning signs, and if needed, look at the disc in partnership with the radiology clinic on the 2nd floor of the same building.

Second, we loosen what's stiff and let the lower back rest. We manage leg pain and tension around the lower back with acupuncture and pharmacopuncture (herbal acupuncture), and restore movement to a stiff pelvis and hip joints with Chuna (Korean manual therapy). We set the hip-hinge movement and flexibility and strength exercises down to the method and number of reps, and check them together at the next visit.

Third, we check by movement and symptoms. At set points, we look at your leg pain score, the extent of numbness, and whether your lower back has stopped folding when you bend forward. We don't treat without evidence.

What changes

A morning when you lift your foot to put on your socks without a second thought. Hands that don't hesitate when you see something you've dropped. A body where the lower back no longer does the pelvis's work.

That's what we aim for.

How fast the movement becomes second nature differs from person to person, depending on how stiff you are, your strength and your living conditions.

Today's takeaway

If you have a herniated disc, don't curl your lower back when you bend forward. Push your hips back. Even with the same movement, the pressure on the disc changes greatly depending on where you fold.

There are two things to try today.

• When you put on socks or wash your face, notice where you fold to bend forward. Does your lower back curl, or do your hips push back?
• Stand with your back to a wall and practice pushing your hips back to touch it, just ten times.

Bring that feeling with you, and we'll help you figure out whether flexibility or strength is what's missing. We're open until 8:30 p.m. on weekdays, and on weekends and public holidays too.

How herniated discs can be reabsorbed on their own, and the evidence behind it, is summarized in the director's column A ruptured disc can shrink on its own.

For questions or appointments, message us in English through the messenger at the bottom right of the page, or call +82-53-716-1175.

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References

Wilke HJ, Neef P, Caimi M, Hoogland T, Claes LE. New in vivo measurements of pressures in the intervertebral disc in daily life. Spine. 1999;24(8):755-762. PMID: 10222525